Plant Genetic Resources newsletter

Transcripción

ISSN 1020-3362
Plant Genetic Resources Newsletter
Bulletin de Ressources Phytogénétiques
Noticiario de Recursos Fitogenéticos
No. 123, 2000
Food and Agriculture Organization of the United Nations and the
International Plant Genetic Resources Institute
Organisation des Nations Unies pour l'alimentation et l'agriculture et
l'institut international des ressources phytogénétiques
Organización de las Naciones Unidas para la Agricultura y la Alimentación y
el Instituto Internacional de Recursos Fitogenéticos
Bureau de
rédaction
Oficina de
Redacción
The designations employed, and the
presentation of material in the periodical, and in maps which appear herein, do not imply the expression of any
opinion whatsoever on the part of
IPGRI or FAO concerning the legal
status of any country, territory, city
or area or its authorities, or concerning the delimitation of its frontiers or
boundaries. Similarly, the views expressed are those of the authors and
do not necessarily reflect the views
of IPGRI or FAO.
Les appellations employées dans
cette publication et la présentation
des données et cartes qui y figurent
n’impliquent de la part de l’IPGRI et
de la FAO aucune prise de position
quant au statut juridique des pays,
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Las denominaciones empleadas, y
la forma en que aparecen presentados los datos en esta publicación,
no implican, de parte del IPGRI o la
FAO, juicio alguno sobre la condición jurídica de países, territorios,
ciudades o zonas, o de sus autoridades, ni respecto de la delimitación
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las de sus autores y no reflejan necesariamente la opinión del IPGRI o
la FAO.
Cover: Close-up of part of a wild
cassava plant in the field. This crop
is discussed in the paper by Allem
(pp. 19-22). Photo by IPGRI.
Couverture: Gros plan d'une plante
sauvage de manioc sur le terrain.
Cette culture est commentée dans
le document de Allem (pp. 19-22).
Photo IPGRI.
Portada: Primer plano de una parte
de la planta silvestre de mandioca
en el campo. Se habla de este cultivo en el documento escrito por Allem (pp. 19-22). Foto del IPGRI.
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© IPGRI/FAO 2000
Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No.
No.
123:
1231- 1
8
ARTICLE
Utilization of germplasm conserved in Chinese
national genebanks – a survey
Gao Weidong¹*, Jiahe Fang¹, Diansheng Zheng¹, Yu Li¹, Xinxiong Lu¹,
Ramanatha V. Rao², Toby Hodgkin³ and Zhang Zongwen4
¹ Institute of Crop Germplasm Resources of the Chinese Academy of Agricultural Sciences, Beijing 100081, China.
² IPGRI Regional Office for Asia, the Pacific and Oceania, Serdang, Malaysia
³ IPGRI, Rome, Italy
4 IPGRI Office for East Asia, Beijing, China
Summary
Résumé
Resumen
Utilization of germplasm
conserved in Chinese national
genebanks – a survey
Enquête sur l’utilisation du
matériel génétique conservé
dans les banques de gènes
nationales en Chine
Estudio del uso de
germoplasma conservado en
bancos nacionales de China
A survey on the use of germplasm conserved in Chinese national genebanks
was conducted jointly by the Institute of
Crop Germplasm Resources of the Chinese Academy of Agricultural Sciences
(CAAS) and IPGRI in 1998-99. A study
was made of the distribution of accessions in the 15-year period from 1984 to
1998, the 10 crops targeted being: rice,
wheat, soyabean, maize, cotton, oranges, tea, mulberry, cabbage and cucumber. The aim was to determine patterns
of germplasm distribution and use, identify constraints to the use of germplasm
conserved in genebanks and suggest
how the situation could be improved.
This investigation was conducted
through a literature review, a questionnaire, a workshop and site visits. The
results showed that 178 495 accessions of
the 10 target crops, including 448 species
and 29 subspecies, have been collected in
China, of which 161 979 accessions were
preserved in seed genebanks and 16 516
accessions in field genebanks. Over the
15-year period, germplasm distributed
by genebanks was used for screening
crop germplasm resources (i.e. for characterization and evaluation for desired
traits), for breeding, for basic research
and for other uses (including direct use in
production). Some accessions were not
used by recipients but only stored as part
of a working collection. The research
identified 24 factors limiting the effective
use of germplasm according to the respondents. For example, most thought
that present policies and systems were
not beneficial to the sharing of crop germplasm resources and that this has led to
insufficient germplasm distribution and
use. Recommendations were made to
increase the use of germplasm in China.
This research could also be considered a
model for surveying the use of germplasm in other countries or genebanks.
Key words: Cabbage, China, cotton,
cucumber, genebanks, germplasm,
maize, mulberry, oranges, rice,
soyabean, tea, wheat
Une enquête sur l’utilisation du matériel
génétique conservé dans les banques de
gènes nationales en Chine a été menée
conjointement par l’Institut des ressources génétiques des plantes cultivées de
l’Académie chinoise des sciences
agronomiques et l’IPGRI en 1998-99. On
a étudié la distribution des accessions sur
une période de 15 ans (1984-1998), pour
10 cultures cibles: riz, blé, soja, maïs,
coton, orange, thé, mûre, chou et concombre, afin de déterminer les modes de
distribution et d’utilisation du matériel
génétique, et d’identifier les obstacles à
l’utilisation du matériel génétique conservé dans les banques de gènes et les
possibilités d’amélioration de la situation.
L’étude a consisté en une étude bibliographique, un questionnaire, un atelier et des visites de sites. Les résultats
montrent que 178 495 accessions des 10
cultures cibles, comprenant 448 espèces
et 29 sous-espèces, ont été collectées en
Chine : 161 979 ont été conservées dans
des banques de semences et 16 516 dans
des collections au champ. Au cours de la
période considérée, le matériel génétique
distribué par les banques de gènes a été
utilisé pour le criblage des ressources
phytogénétiques (caractérisation et évaluation), la sélection, la recherche fondamentale, l’utilisation directe (culture), etc.
Certaines accessions n’ont pas été utilisées par les bénéficiaires, mais conservées dans une collection de travail.
L’enquête a permis d’identifier 24 facteurs qui, selon les personnes interrogées, limitent l’utilisation efficace du
matériel génétique. La plupart estiment
que les politiques et systèmes actuels ne
favorisent pas le partage des ressources
phytogénétiques, d’où une distribution
et une utilisation insuffisantes de ce matériel. Des recommandations sont formulées pour le développement de
l’utilisation du matériel génétique en
Chine. Cette enquête pourrait servir de
modèle à des études similaires dans
d’autres pays ou d’autres banques de
gènes.
El
Instituto
de
Recursos
de
Germoplasma Vegetal de la Academia
China de Ciencias Agrícolas y el IPGRI
estudiaron conjuntamente en 1998-99 el
uso de germoplasma conservado en
bancos de germoplasma nacionales de
China. Se estudió la distribución de
accesiones durante 15 años (1984- 1998),
de 10 cultivos: arroz, trigo, soja, maíz,
algodón, naranjas, té, mora, col y pepino.
Se pretendía determinar pautas de
distribución y uso de germoplasma,
señalar las limitaciones en el uso del
germoplasma conservado en los bancos
y sugerir formas de mejorar la situación.
La investigación se realizó a través de
una revisión de la bibliografía, un
cuestionario, una taller y visitas sobre el
terreno. Se constató que se habían
recogido en China 178 495 accesiones de
las 10 plantas citadas, correspondientes a
448 especies y 29 subespecies, de las
cuales 161 979 accesiones se conservaban
en bancos de semillas y 16 516 accesiones
en bancos en el campo. Durante los 15
años, el germoplasma distribuido por los
bancos se utilizó para seleccionar recursos
de germoplasma (o sea para caracterizar
y evaluar rasgos deseados), para mejora
genética, para investigación básica y para
otros usos (como el uso directo en la
producción). Los receptores no usaban
todas las accesiones, sino que guardaban
algunas como parte de una colección de
trabajo. Se enumeraron 24 factores
limitativos del uso efectivo del
germoplasma según los encuestados.
Por ejemplo, la mayoría pensaban que
las políticas y sistemas actuales no
favorecen el intercambio de recursos de
germoplasma y que por ello son
insuficientes su distribución y su uso. Se
formularon recomendaciones para
aumentar el uso de germoplasma en
China. Este trabajo puede servir de
modelo para estudiar el uso de
germoplasma en otros países o bancos
de germoplasma.
2
Plant Genetic Resources Newsletter, 2000, No. 123
Introduction
Over the 15-year period under study, from 1984 to 1998, the
central government in Beijing has established a modern longterm storage genebank, a duplicate genebank and a number of
medium-term genebanks for germplasm exchange. In addition,
32 national germplasm nurseries for perennial and vegetatively
propagated crops (including two in vitro banks), and 21 local and
provincial medium-term genebanks have been established nationwide. These provide basic facilities for the conservation and
research of crop genetic resources. By September 1998, the
germplasm preserved in the national genebanks and nurseries
had reached 355 000 accessions. Of these, 318 000 accessions of
161 crops, belonging to more than 600 species of 174 genera of
30 families, are preserved in the long-term genebank and over 37
000 accessions of more than 50 crops, belonging to 1026 species
or subspecies, are preserved in the germplasm nurseries.
Germplasm conserved in genebanks accounts for approximately
85% of accessions collected in China. Much of this is endemic to
China and includes rare germplasm and wild relatives of crops,
including elite material for crop improvement (Gao Weidong
and Shumin Wang 1997).
In the same period genebanks have also distributed hundreds of thousands of germplasm to institutions and researchers at home and abroad. However, the use being made of the
distributed germplasm is unclear. There still seems to exist in
China the belief that “crop germplasm resources are abundant
but breeding materials are scarce”. Although some factors limiting the effective use of germplasm are known, little has been
done to examine the extent of this or how to reduce the phenomenon. The present project aimed to explore the use of germplasm
in China from 1984 to 1998 in order to collect information on
germplasm utilization in agriculture, genetic research, character
evaluation, germplasm enhancement and exploitation; provide
a scientific basis for solving the problems mentioned above, and
formulate strategies to increase the use of crop germplasm resources.
Materials and methods
Target crops
The target crops include rice, wheat, soyabean, maize, cotton,
citrus, tea, mulberry, Peking cabbage and cucumber. Information on the distribution, exchange and utilization of this
germplasm, which is preserved in the national medium-term
genebanks, nurseries and local genebanks, was collected for the
15-year period 1984 to 1998.
Major activities
Survey by questionnaire
A total of 676 questionnaires were sent to experts in China (580)
and abroad (96) at the beginning of January 1999. By the end of
June 1999, 249 questionnaires (36.8%) had been returned. Approximately 41% of Chinese scientists responded and 11.5% of
scientists from other countries (Table 1).
Literature review
More than 120 papers and other documents on germplasm
utilization in China were reviewed, such as Chinese Agricul-
tural Sciences, Acta Genetica Sinica, Acta Botanica Sinica, Acta
Phytophysiologica Sinica, Acta Phytochemica Sinica, Acta
Agronomica Sinica, Journal of Crops, Acta Entomologica Sinica,
Crop Genetic Resources, Chinese Rice Sciences, Triticeae crops,
Maize Sciences, Soybean Sciences, Fruit Sciences, Acta
Horticulturae Sinica, Cotton in China, Citrus in China, Vegetables in China, Tea Sciences, Mulberry Sciences and other local
journals.
Workshop
A workshop on the status of germplasm utilization, problems
and solutions at the national genebanks/nurseries in China
was held from 26 to 27 May 1999 and hosted by the Institute of
Crop Germplasm Resources of Chinese Academy of Agricultural Sciences (CAAS). Twenty-one scientists from different
institutions attended the workshop.
Case studies
Experts undertook on-the-spot investigations at 13 institutes:
the Crop Cultivation and Breeding Institute, the Cotton Institute, the Citrus Institute, the Vegetable and Flower Institute, the
Tea Institute, the Mulberry Institute and the Crop Germplasm
Resources Institute all of CAAS; the China Rice Research Institute; the Jilin Academy of Agricultural Sciences; the Shanxi
Academy of Agricultural Sciences; the Hainan Academy of
Agricultural Sciences; the Northeast Agricultural University;
and the Nanjing Agricultural University. The focus was on
investigating the status of germplasm distribution and utilization for the 10 crops identified.
Results and discussion
Germplasm preservation
A total of 178 495 accessions of the target 10 crops, consisting of
448 biological species and 29 subspecies, have been collected in
China (Table 2). Of these, 161 979 accessions are preserved in
genebanks and 16 516 accessions are preserved in nurseries.
Germplasm distribution
Given the information in the survey, it is evident that germplasm
distribution for the 10 crops made great progress in 15-year period
examined (Table 3). A total of 184 743 accessions were distributed
to 8635 institutions concerned with crop breeding, basic research,
production and teaching. The material distributed included bred
varieties, breeding lines, landraces, wild relatives and genetic
stock. The crops were rice, wheat, maize, soyabean, cotton, citrus,
Peking cabbage, cucumber, tea tree and mulberry.
Germplasm utilization
The current project investigated the status of germplasm utilization for the 10 target crops (Table 4). It was shown that the
use of germplasm could be divided into five areas: screening,
breeding, basic research, other uses and no use made of the
material. According to the survey, of the 136 802 accessions
received in the 15-year period, 21% of the total were used for
screening crop germplasm resources, 8.1% for breeding, 9.0%
for basic research, 2.0% for other purposes and 59.9% were not
used at all.
Plant Genetic Resources Newsletter, 2000, No. 123 3
Table 1. General information concerning respondents
Respondents
from China
Respondents
from abroad
Total
Activity
No.
%
No.
%
No.
%
Curator
Breeder
Curator
and breeder
Other
Total
43
88
101
18.1
37.0
42.4
2
1
7
18.2
9.1
63.6
45
89
108
18.1
35.7
43.4
6
238
2.5
41.0
1
11
9.1
11.5
7
249
2.8
36.8
From Table 4 it can be seen that mainly cultivars were
used for breeding, with the percentage of wild relatives used
being considerably lower (0.4%), although their potential is
noteworthy. Landraces and breeding lines were used mainly
for screening useful characteristics and genetic stock was
used mainly for basic research. Wild relatives were used for
screening and basic research, and cultivars were mainly
used for screening. Further information on the use of
germplasm in breeding, production and basic research is
given below.
Table 2. Conservation status of 10 target crops in China
Crop
Rice
Wheat
Maize
Soyabean
Cotton
Citrus
Peking cabbage
Cucumber
Tea tree
Mulberry
Total
Species
36
297
1
3
60
22
–
1
17
11
448
Subspecies
2
18
–
–
–
–
1
–
5
3
29
Accessions conserved
Genebank Nursery
Total
64 390
41 013
15 967
31 206
6264
–
1665
1474
–
–
161 979
73 323
42 811
15 967
31 206
6724
1041
1665
1474
2527
1757
178 495
8933
1798
–
–
460
1041
–
–
2527
1757
16 516
The use of germplasm in breeding
The 13 breeding institutes that received accessions used 21.1% in crop improvement
(Table 5). Altogether 1281 varieties were bred
using 1487 accessions. Of the 1487 accessions, 0.8% were from genebanks and nurseries. This indicates that the rate of effective
use was higher for cash crops than for field
crops. The total area planted with varieties
bred using germplasm received as parents
has been estimated at 37 481 720 ha for the
15-year period. This is 25.2% of the total
area planted with the target crops. Of the
total area cultivated with germplasm received from genebanks or nurseries, 18 497
400 ha was planted with rice, 10 207 400 ha
Table 3. The status of germplasm distribution by germplasm holders for 10 target crops (1984-98)
Crop
Landraces
Advanced
lines
Genetic
stocks
Wild
relatives
Rice
Wheat
Maize
Soyabean
Cotton
Citrus
Peking cabbage
Cucumber
Tea
Mulberry
Total
8586
2517
800
8850
31
10 440
2500
2200
4500
1000
41 424 (22.4%)
26 700
23 566
1000
2500
4510
–
900
750
–
85
60 011 (32.5%)
450
1989
100
250
135
744
45
–
300
35
4048 (2.2%)
949
1508
10
1500
55
1417
–
–
2175
50
7664 (4.1%)
Cultivars
Total (%)
21 065
23 430
3000
5000
10 269
7310
60
30
910
522
71 596 (38.8%)
57 750 (31.3)
53 010 (28.7)
4910 (2.7)
18 100 (9.8)
15 000 (8.1)
19 911(10.8)
3505 (1.9)
2980 (1.6)
7885 (4.3)
1692 (0.9)
184 743
Table 4. Information on the use of the germplasm received for the target crops (1984-98)
Germplasm use
Landraces
Advanced
lines
Genetic
stocks
Wild
relatives
Cultivars
Total
Germplasm received
Screening
No.
%
Breeding
No.
%
Basic research
No.
%
Other (including
No.
direct use)
%
Not used
No.
%
40 701
9668
23.8
2390
5.9
3557
8.7
605
1.5
24 481
60.1
54 114
9562
17.6
4258
7.9
3028
5.6
1305
2.4
35 961
66.5
1 348
160
11.9
57
4.2
769
57.0
50
3.7
312
23.2
6729
634
9.4
27
0.4
638
9.5
35
0.5
5395
80.2
33 910
8731
25.8
4345
12.8
4286
12.6
712
2.1
15 836
46.7
136 802
28 755
21
11 077
8.1
12 278
9.0
2707
2.0
81 985
59.9
4
Table 5. Utilization of germplasm received at the 13 main breeding centres (1984-98)
Germplasm involved in
development of released varieties
Total area
cultivated
Germplasm used
for breeding
From
genebanks
Total
Crop†
‘000 ha
Germplasm
received
No.
%
Varieties
bred
No.
%
No.
Rice
Wheat
Maize
Soyabean
Cotton
Citrus
Cucumber
Tea
Mulberry
Total
18 497.67
10 207.40
6609.09
300.80
1789.29
2.54
66.90
4.11
3.92
37 481.72
35 000
53 010
4523
13 300
1662
700
1474
1772
398
11 1839
3260
13 252
733
4633
1170
138
400
34
30
23 650
9.3
25.0
16.2
34.8
70.4
19.7
27.1
1.92
7.5
21.1
376
267
120
292
192
8
64
109
19
1 447
303
213
87
36
163
11
32
34
13
892
0.87
0.4
1.92
0.27
9.8
1.57
2.17
1.92
3.27
0.8
393
1.12
424
0.8
141
3.1
71
5.3
282 16.9
17
2.43
106
7.19
34
1.92
20
5.03
1487 1.33
†
%
Peking cabbage was not included.
with wheat, 6 609 090 ha with maize and 1 789 290 ha with
varieties of cotton.
Currently, 85% of the major crops in China are grown using
modern varieties. This has resulted in annual rice yields rising
from 5250 kg/ha in 1985 to 6319 kg/ha in 1997, wheat yields
from 2490 kg/ha in 1985 to 4101 kg/ha in 1997, corn yields from
3600 kg/ha in 1985 to 4387 kg/ha in 1997, soyabean from 1365
kg/ha in 1985 to 1764 kg/ha in 1997 and cotton from 810 kg/ha
in 1985 to 1024 kg/ha in 1997. In addition, approximately 7080% of maize is grown using maize hybrids. All of these achievements are closely dependent upon the use of crop germplasm.
Xiaohongmai has been grown for its drought tolerance in the
Inner Mongolian Region for at least 100 years and the rice
landraces Zhubao and Yabao have been grown in Lingshui
County of Hainan Province (where the Li ethnic group lives) for at
least 30 years. The use of landraces has not only protected
biodiversity but also helped to develop local economies.
However, new varieties with high yields, good quality and
resistance to diseases and pests have replaced landraces in most
regions, although landraces are still used in some remote regions
and areas where minor ethnic groups live. Prof. Manmao Qian
(Qian et al. 1996) has estimated that in the 1950s nearly 10 000
wheat cultivars were still being used in China but that only 300
Direct use in production
improved varieties are currently in use.
The survey showed that in the 15-year period under discussion,
The survey results showed that approximately 66 major rice
178 landraces were directly used in production on 12 722 000 ha, landraces, such as Laohudao and Hongkewan, are used in rice
accounting for 0.9% of the cultivated area grown with the target production on 77.5% of the total area grown with landraces in
crops (Table 6). In general, improved varieties of field crops have the 15-year period. For soyabean, 13 major landraces are still
been in production for 3-7 years, tea trees and mulberry for 5-15 currently used in production including Shizhu Zhuyaozi of
years and vegetables for 2-4 years. Landraces, however, have been Sichuan and Juhuang of Guangdong, with a growing area 8.3%
in use for much longer. For example, the wheat landrace of the area grown with landraces. Other major landraces include
Xiaohongmai for wheat on 7.8% of the area planted;
Table 6. Use of landraces for the 10 target crops (1984-98)
Baibaomi, Huobaomi and Huanghuoyumi for maize
on 3.2% of the area planted; Husang 32, Dahuasang
No. of
and Dayibai for mulberry on 1.3% of the area
landraces
Growing
planted; Yichuanling and Xintaimici for cucumber
Crop
used
Elite traits used
area (ha)
on 1.0% of the area planted; 15 landraces such as
Rice
66
Disease resistance
9 909 000
Qichen and Xuechen for citrus on 0.3% of the area
Wheat
1
Stress tolerance
1 000 000
planted, and 50 landraces, such as Xuchuan
Maize
10
Disease resistance, early
46 031
Gouniannaocha of Jiangxi and Tenchong
maturity, drought tolerance
Wenjiatangdayecha of Yunnan for tea on 0.1% of
Soyabean
13
Large grain, used for
1 064 050
vegetables, early maturity
the total area planted with landraces. No landraces
Citrus
15
Good quality, high yield,
39 700
are used to grow cotton.
Cucumber
Tea
Mulberry
Total
4
50
19
178
early maturity
Disease resistance,
cold tolerance
Good quality, high yield
High yield
124 500
16 055
163 388
12 362 724
Basic research
For the 10 target crops, 12 278 accessions were used
for basic research (see Table 4). This has mainly
focused on the following areas: genetics and the
mechanism of heterosis, botany, plant taxonomy, biological
diversity, plant physiology, plant biochemistry, phytopathology and resistance mechanisms, molecular biology, genetic engineering, cytological engineering and environmental biology.
Most of the research results were published in China.
Limiting factors in the use of germplasm resources
The use of crop germplasm resources in China has made great
progress since 1984. However, there are some factors which limit
its effective use (see Table 7). The survey investigated the views
of respondents working in different areas of genetic resources.
The questions can be divided into five categories: (a) characterization and evaluation (8-11), (b) exchange and communication
(1, 2, 4, 14), (c) germplasm enhancement (13), (d) policies (1922) and (e) other factors. Respondents differed on numbers 3, 57, 12, 15-18, 23 and 24 which came under (e) and were in
agreement on questions 1, 8-11, 13 and 19-22. Further details
are given in Table 8.
Germplasm characterization and evaluation
The survey showed that there was a lack of in-depth studies on
the huge collections and basically that germplasm was characterized and evaluated phenotypically, which led to an unclear
understanding of its use value. For some accessions, no characterization and evaluation of agronomic characters, resistance to
disease and pests or tolerance to stress had been carried out. For
example, although all the wheat germplasm (38 000 accessions)
preserved in the national genebanks had been characterized
agronomically, resistance to seven diseases had been evaluated
for only 22 000 accessions, drought tolerance for only 15 000
accessions, cold and salt tolerance for only 2000-3000 accessions, and crude protein and lysine content for only 20 000
accessions. Approximately two-thirds of maize germplasm had
been characterized and evaluated for resistance to disease and
pests, stress tolerance and quality analysis. This lack of characterization and evaluation has undoubtedly limited, to some
extent, the wide use of the rich genetic diversity available and
the enhancement of germplasm.
Germplasm exchange and communication
Medium-term germplasm exchange banks, facilities for
germplasm multiplication and regeneration, and information
networks are needed for the effective use of germplasm resources. For many reasons, however, these facilities have not
been established or perfected. Most of the medium-term
genebanks are located in different provinces and are responsible
for the medium-term preservation of local germplasm. Some
provinces have no modern medium-term genebanks and the
conditions for preservation are poor. Approximately 7% of respondents have long-term genebanks, 20% medium-term banks,
42% germplasm nurseries, 29% working genebanks and 2% no
genebanks. Moreover, because of the lack of funding for the
regeneration of germplasm preserved in the medium-term banks,
no material is available for distribution and some accessions
have been lost.
As some provincial medium-term genebanks are not linked to
the National Germplasm Information Database, this has led to
the ineffective germplasm and information exchange between
units working on germplasm and units working on breeding and
basic research. Thus, some germplasm curators are unaware of
Table 7. Factors limiting the use of crop germplasm resources (CGR)
No.
Statement
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Limited exchange of CGR information
Breeders do not know CGR information in genebanks
Curators do not know breeders’ needs
Poor distribution of CGR
Insufficient number of CGR for target crop in genebanks
Insufficient number of useful CGR for target crop in genebanks
Little genetic diversity of target crop preserved in genebanks
Insufficient characterization and evaluation in genebanks
Insufficient characterization and evaluation for disease and pest resistance of CGR in genebanks
Insufficient characterization and evaluation for stress tolerance (e.g. cold, drought, salt, etc.) of CGR in genebanks
Insufficient genetic evaluation of CGR in genebanks
Unreliable data of CGR characterization and evaluation
Insufficient CGR enhancement
Obtaining desirable CGR from national medium-term genebanks is difficult
Amount of CGR supplied by national genebanks is not sufficient to meet needs
Time taken to respond and provide CGR requested is very long
Obtaining CGR from national medium-term genebanks is expensive
Property right may be involved if CGR from other Chinese institutions is used
Elite materials held by breeders is not preserved in genebanks
Present policies and systems are not beneficial to CGR sharing
Government has not paid great attention to genetic resource activities
Breeders do not request CGR from curators
Introduction of desirable materials from other countries is faster and less expensive than requesting them from
Chinese institutes or enhancement by self
Requests for CGR are sometimes limited by policies, e.g. only institutions that send CGR to the genebank can obtain
the CGR
24
6
breeders’ urgent requirements and breeders are unaware of the
information available on germplasm. This has resulted in the
inaccurate objectives of both curators and breeders.
Germplasm enhancement
Germplasm enhancement to broaden genetic diversity is very
important for the effective use of germplasm resources. In China,
poor germplasm enhancement and improvement has led to the
poor exploitation and inefficient use of elite germplasm. With
the exception of a few landraces, it is impossible that all
germplasm traits are elite. In the past, breeders used traditional
breeding methods to develop varieties and they often needed
only one or two elite traits. Nowadays they require materials
with more elite traits resulting in an urgent need for germplasm
enhancement.
Policies
Firstly, although the Government has paid considerable attention
to crop germplasm resources in the past two decades, not enough
has been done to support such a huge undertaking and insufficient resources have been given to increasing public awareness.
Secondly, in general the Government does not give high priority to
germplasm management and this has led to the lack of funds and
poor equipment in some genebanks. Thirdly, present policies do
not facilitate sharing germplasm between holders and users, and
the intellectual property rights of holders and breeders cannot be
protected effectively. This is why some elite material owned by
breeders is not preserved in the national genebanks and/or nurseries and, therefore, cannot be used by others.
Other factors
Respondents had different opinions on the following questions.
(a) Do germplasm curators know the needs of breeders? (b) Are
the accessions preserved in the genebanks sufficient for research? (c) Is there enough useful germplasm in the genebanks?
(d) Is there sufficient genetic diversity in the accessions preserved in the genebanks? (e) Is the amount of seed provided
enough? (f) Does the time for seed provision take too long? (g) Is
the cost of obtaining germplasm from the genebanks too high?
(h) Is the introduction of parents from abroad faster and quicker
than waiting for germplasm enhancement by breeders? An
analysis of the returned questionnaires is given in Table 8.
Analysis of limiting factors involved in germplasm
utilization
The use of germplasm resources
The survey supports the view that germplasm should be further
evaluated to promote its utilization. Over 90% of respondents
stated they would use germplasm for breeding purposes if it was
evaluated more. Lack of funds is considered to be the most
important limiting factor in the use of germplasm, followed by
policy, evaluation, information and others.
Germplasm sharing
The survey showed that more than half the respondents proposed that the sharing of germplasm should conform to the
principle of bilateral benefit, that is, breeders or others who hope
to use the germplasm preserved in the genebanks may obtain
materials required but at considerable cost. This is perhaps a
Table 8. Analysis of factors limiting germplasm utilization
Factor
Response
Germplasm received needs further evaluation
Yes
No
Yes
No
Financial
Policies
Characterization and evaluation data
Information
Other
Policies
Lack of useful germplasm
Lack of information
Other
Catalogues
Journals
Database systems
Oral presentation
Other
Bilateral benefits
Distribution free of charge
Other
No policy guarantee benefits
No mutual understanding
Low genetic diversity of
germplasm in genebanks
Belief that other breeders do
not have elite germplasm
Other
Germplasm received is used in breeding programmes
Major limiting factors in using germplasm
Most serious problems in germplasm enhancement
Major approaches to access information of germplasm
Ways to share information and elite germplasm
Major difficulties in germplasm exchange among
breeders and curators
China (%)
Abroad (%)
90
8
98
2
45
31
14
9
1
34
27
19
20
34
36
7
20
3
79
18
3
55
29
8
80
20
80
20
33
33
17
17
0
37
13
25
25
33
22
28
17
0
50
40
10
33.3
33.3
11.1
2
11.1
6
11.1
good way for developing countries, such as China, to
sustainably run genebanks and nurseries, and provide materials
to breeders and other users. However, the measures taken should
be in keeping with the requirements of the International Undertaking on Plant Genetic Resources.
Germplasm enhancement
According to the respondents, the major limiting factors for
germplasm enhancement are policies, the lack of useful
germplasm and the shortage of information. Policies are the
main bottleneck but determining which materials should be
enhanced is also critical.
Germplasm and information exchange
The difficulties in germplasm and information exchange mainly
result from the lack of protection of intellectual property rights
and the lack of communication between breeders and curators.
Breeders and other germplasm users obtain information concerning germplasm mainly via catalogues and journals. However, scientists in other countries also obtain information via
information databases. Some Chinese scientists are now beginning to use these methods.
Suggestions and recommendations
During this study, experts from different fields made many
suggestions on how to effectively improve the use of germplasm.
After careful analysis of these suggestions, the following list of
proposals has been drawn up.
1. Strengthening characterization, evaluation and
the enhancement of germplasm
While germplasm collecting and preservation should continue,
in the near future the emphasis should be shifted to characterization and evaluation, and in-depth research into germplasm
resources. Biotechnology, including the use of molecular markers, cell engineering and genetic engineering, should be used in
germplasm enhancement and more genotyping should be conducted. In particular, favourable genes existing in wild relatives
of crops should be transferred to cultivars to obtain new types of
germplasm. Germplasm researchers should provide not only
elite germplasm but also information concerning its characteristics and genetic mechanism in order to improve the use of the
material.
Germplasm enhancement should target diverse ecological
regions and diverse breeding objectives. For wild relatives especially, more trials and research is needed in order to exploit
potential value. Germplasm researchers should understand the
unique advantages and the accompanying disadvantages of their
own accessions, and then form clear objectives to improve them.
2. Promoting the exchange of germplasm and
associated information
Approximately 350 000 accessions are preserved in the National
Genebank of China and in medium-term genebanks. However,
the limited multiplication of accessions in China seriously influences the distribution and exchange of germplasm resources. It
is suggested that germplasm researchers should increase and
improve their contacts with breeders to exchange germplasm
and associated information. To do this, various activities need
to be organized such as ecogeographical trials. These should
include material from different ecological regions and provide
opportunities for interaction between germplasm researchers
and users as well as farmers. A national information network,
accessible to breeders and other researchers, should also be
developed to provide relevant information on germplasm conservation, characterization, evaluation and enhancement.
3. Formulating benefit-sharing policies
Benefit-sharing policies for the use of germplasm should be
drawn up in order to encourage cooperation between germplasm
holders and users. On the one hand, this should include the
principle that germplasm providers should benefit from the use
of their germplasm by breeders and other researchers, while on
other, encourage breeders to send their improved and enhanced
elite materials to genebanks for preservation, exchange and use.
Paid germplasm services could be considered as a way of satisfying users and meeting the needs of the market.
4. Strengthening financial support
The Government should increase its support for the conservation and use of germplasm resources. This is critical for promoting the various activities needed to increase the use of
germplasm. At the same time, each institution concerned with
germplasm should apply for funds, through the various channels available, to carry out research to identify, evaluate, enhance and ensure the provision of useful germplasm for crop
improvement and other purposes.
5. Establishing a national coordinating mechanism
A national coordinating mechanism is essential for the promotion of the use of plant genetic resources in China and a national
committee for plant genetic resources should be the coordinating and decision-making body in the country, composed of
officials from various sectors, as well as experts on conservation
and the use of plant genetic resources. This body would be
responsible for formulating rules and management policies, and
for making short- medium- and long-term plans for action.
6. Future work
It is suggested that the proceedings of the workshop organized
for this project be published. This provides useful information
on the use of crop genetic resources, particularly for the 10 target
crops, and will assist scientists and the relevant authorities to
make the decisions needed to strengthen the national
programme for the conservation and use of crop germplasm in
China. This information will also be of use to scientists and
organizations concerned with plant genetic resources in other
countries.
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Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No. No.
123:123
9 - 18
9
ARTICLE
The use of home gardens as a component of the
national strategy for the in situ conservation of plant
genetic resources in Cuba
L. Castiñeiras1*, Z. Fundora Mayor1, S. Pico1 and E. Salinas2
Instituto de Investigaciones Fundamentales en Agricultura Tropical “Alejandro de Humboldt” (INIFAT), Calle 2 esqu. 1,
Santiago de las Vegas, Ciudad de La Habana, Cuba. Tel: +53 7 579308; Fax: +53 7 579014; Email: [email protected]
2 Facultad de Geografía de la Universidad de La Habana, Calle 23 esqu. a L. Vedado Plaza, Ciudad de La Habana, Cuba
1
Summary
The use of home gardens as a
component of the national
strategy for the in situ
conservation of plant genetic
resources in Cuba
This study determines and describes the
factors to be considered when developing a plan for the use of home gardens
(“conucos”) as part of the in situ conservation of Cuban cultivated plant genetic
resources. These factors were geographical, environmental, cultural, ethnological, phytogenetic, socioeconomic and
type of agricultural production system,
whether private or cooperative. On the
basis of these and the diversity found in
the “conucos” of the various provinces,
30 areas with different characteristics
were selected from 12 provinces and the
special municipality of Isla de la Juventud.
The study also included the monitoring
of some species for infraspecific variability, selected on the basis of their importance, origin and domestication in the
Central American and Caribbean regions. On the basis of this study it is
proposed to use home gardens to conserve plant genetic diversity and to integrate them into the existing ex situ
(genebanks and botanical gardens) and
in situ (protected areas) conservation
programmes, as well as with socioeconomic programmes. The questionnaire
used to select and monitor the “conucos”
is given as an appendix.
Key words: Ethnology, ex situ, home
gardens, in situ, socioeconomics
Résumé
Utilisation des jardins
familiaux comme composante
de la stratégie nationale pour
la conservation in situ des
ressources phytogénétiques à
Cuba
Cette étude détermine et décrit les facteurs à prendre en compte lorsqu’on
élabore un plan pour l’utilisation des jardins familiaux (“conucos”) dans le cadre
de la conservation in situ des ressources
génétiques des plantes cultivées à Cuba.
Il s’agit de facteurs géographiques, environnementaux, culturels, ethnologiques,
phytogénétiques, socioéconomiques et
relatifs aux types de systèmes de production agricole, qu’ils soient privés ou
coopératifs. Sur la base de ces facteurs et
de la diversité présente dans les “conucos” des diverses provinces, 30 zones
présentant des caractéristiques différentes ont été sélectionnées dans 12
provinces et la municipalité spéciale de
Isla de la Juventud. L’étude comprend
également le suivi de plusieurs espèces
pour leur variabilité infraspécifique,
choisies en fonction de leur importance,
de leur origine et de leur domestication
dans les régions d’Amérique centrale et
des Caraïbes. Sur la base de cette étude, il
est proposé d’utiliser les jardins familiaux
pour conserver la diversité génétique des
végétaux et de les intégrer dans les programmes de conservation ex situ
(banques de gènes et jardins botaniques)
et in situ (zones protégées) en cours, ainsi
que dans des programmes socioéconomiques. Le questionnaire utilisé
pour le choix et le suivi des “conucos”
figure en annexe.
Resumen
Los huertos familiares como
parte de la estrategia nacional
para la conservación in situ de
los recursos fitogenéticos en
Cuba
Este estudio enumera y describe los factores que hay que considerar para planificar el uso de los huertos familiares (“conucos”) con miras a la conservación in
situ de los recursos genéticos de plantas
cultivadas cubanas. Tales factores son
geográficos, ambientales, culturales, etnológicos, fitogenéticos, socioeconómicos y relativos al sistema de producción
agrícola, privada o en cooperativa. Sobre
esta base y en función de la diversidad de
“conucos” de varias provincias, se seleccionaron 30 zonas con características
diferentes en 12 provincias y en el municipio especial de Isla de la Juventud. Se
observó también la variabilidad intraespecífica de algunas especies seleccionadas por su importancia, su origen y
su domesticación en América Central y
el Caribe. Sobre la base de este estudio se
propone utilizar los huertos familiares
para conservar la diversidad fitogenética
e integrarlos en los actuales programas
de conservación ex situ (bancos de germoplasma y jardines botánicos) e in situ
(zones protegidos), así como en los programas socioeconómicos. En el apéndice
puede verse el cuestionario utilizado para
seleccionar y observar los “conucos”.
Introduction
Cuba has a rich natural flora with approximately 6700 species
of vascular plants distributed in 1300 genera and 181 families.
Nearly 50% of the flora is endemic, one of the highest percentages in the Antillean area (Capote et al. 1992).
Many authors have commented on the importance of home
gardens for the in situ conservation of plant genetic resources.
Altieri and Merrick (1987) and Altieri et al. (1987) discussed the role
of in situ conservation in preserving traditional agricultural systems
and Niñez (1986) pointed out that home gardens are a useful
mechanism for conserving non-crop species and that, depending
upon the diversity present, they can be considered as genebanks for
primitive cultivars with a potential value. Ragione and Perrino
(1995) have described a successful example of on-farm conservation of old fruit tree varieties in the Timber Valley, Italy, carried out
for a number of years by several groups composed of farmers, local
cooperatives and/or regional associations, farmer’s associations,
local and regional institutions, amateur clubs and private nurseries.
Salazar (1996) also discussed the important role of home gardens in
rural communities for the conservation of rice in Viet Nam. Nevertheless, it is important to note that because of the small size of plant
populations involved in home gardens, there is a risk of gene loss
through genetic drift and founder effect.
10
As Esquivel and Hammer (1994) pointed out, the in situ
conservation of landraces and their wild relatives through the
use of “conucos” in Cuba is important because it allows for the
continuous process of evolution by means of introgression,
domestication and adaptation to unfavourable conditions to
take place in the natural environment. This has given rise to an
interesting variability of cultivated plants in Cuba. These authors also stressed the importance of “conucos” as a refuge for
landraces and obsolete cultivars, which are rich reservoirs of
genes for adaptation and resistance.
“Conucos” are small gardens where farmers practise traditional agriculture mainly based on local cultivars. They are also
referred to as “vega”, “sitio” or “patio”, depending on their size
and the locality in which they occur. A number of studies have
been carried out on the historical development, structure and
composition of Cuban “conucos” (Esquivel and Hammer 1988,
1992a, b). In some cases mixed gardens overspill into tropical
forests making it difficult to identify the borders between them.
The authors observed a total of 80 taxa in the six “conucos”
studied and these were classified according to their use.
Activities concerning plant genetic resources are supported
by the State through the National System of Plant Genetic
Resources (NSPGR), which is composed of a network of
genebanks belonging to different institutions and ministries
throughout the country where ex situ collections of the most
important crops are preserved. These include, among others,
sugar cane, tobacco, vegetables, grains, oil seeds, major tropical
roots and tubers, bananas and plantains, citrus and fruit crops.
The National System of Protected Areas, which are identified
and managed according to the regulations of the World Conservation Union , is also integrated into the NSPGR.
Home gardens are integrated with the protected areas used
to preserve primitive and obsolete cultivated species. It is proposed to integrate these with the ex situ conservation strategies
already existing in Cuba. According to Hodgkin (1995) there are
two main considerations that need to be taken into account
when considering the in situ conservation of plant genetic resources of cultivated plants: (a) the factors influencing farmers’
decisions to maintain diversity in their crops and (b) the approaches that could support farmers in maintaining diversity.
The objectives of this study are: (a) to identify and describe the
factors to be considered in developing a plan to use “conucos” as
part of Cuba’s in situ conservation strategy, (b) to determine
potential areas where “conucos” can contribute to the in situ
preservation of the genetic resources of cultivated plants, on the
basis of geographical, ethnological, phytogenetical and socioeconomic factors, and (c) analyze the possibility of creating a network of areas of in situ conservation using “conucos” to complement the already existing ex situ conservation programmes.
vation of plant diversity were also examined, taking into consideration the different cultures that converge in Cuba (Rivero de la
Calle 1966; Franco 1975; Ortiz 1975; Pérez de la Riva 1977; Valdés
1978, 1986; Dacal and Rivero de la Calle 1986).
Wild and cultivated plants were analyzed and a survey
undertaken of their origins and use in accordance with the
scientific studies performed by Esquivel et al. (1989), Capote et al.
(1992), Hammer et al. (1992), Knüpffer (1992), Rodríguez et al.
(1992), and on previous collecting missions carried out in Cuba.
In addition, socioeconomic factors affecting the Cuban agricultural system and types of land tenancy were studied to examine
the importance that each gives to subsistence agriculture
(MINAG 1991; Santana 1991).
Results
Secondary data used
Major geographical factors were examined according to Salinas
and Salinas (1992), and the types of Cuban landscape and their
human modification over time were also analyzed to understand
their effect on biodiversity (Perera 1986; Perera and Rosabal 1986;
Leiva 1992). Ethnological factors that could influence the preser-
The factors that need to be considered for the in situ conservation
of cultivated plant genetic resources are given below.
Analysis of secondary data
Considering the data obtained on the main types of landscapes
and the ethnological, phytogenetical and socioeconomic factors,
11 provinces were identified where “conucos” could be used for
the in situ conservation of cultivated plants. In each area two to
three families were visited. In some cases, once the purpose of
the research had been explained, sites were recommended by
members of the provincial delegations from the Ministry of
Agriculture or by local experts As they knew the areas, including
the crops grown, the production systems and the farmers, they
were able to judge their suitability. In other cases they were
selected at random by observing possible sites from the road.
In order to prepare the exploration of the selected areas and
to identify potential “conucos”, the mission examined information accumulated during previous visits and collecting missions, as well as the detailed studies of “conucos” carried out
during the INIFAT-ZIGuK collaboration that took place between 1986-1993 (Esquivel and Hammer 1988; Esquivel et al.
1990, Esquivel and Hammer 1992a, 1992b; Hammer et al. 1992;
Esquivel and Hammer 1994).
Exploration missions
A questionnaire was prepared to provide the data needed to
select “conucos”. This included an introduction, general questions, data on the locality, ethnological data, data on the
“conuco” (origin, area, destination of the production and its
possible use) and specific information about the plants grown.
This served as a guide for the exchange of information with the
farmers and is given in Appendix 1.
An inventory was made of cultivated plants present in the
“conucos” to select possible species that merit conservation and
to monitor variability. The study of infraspecific variability was
based on visual observations of flower and fruit characteristics
using IPGRI descriptors. In some cases infraspecific variability
was obtained from interviews with farmers.
Geography
There are three main geographical features in Cuba: insularity
(predominance of coastal landscapes and a strong marine influ-
ence on natural elements); geological and geomorphological
complexity (the association of reliefs, plains and mountains,
and the combination of the different types of relief); and climate
(significant influence of winds and great variation in humidity
associated with a very complex rain regime).
Prior to 1492 when Cuba was ‘discovered’ by Christopher
Columbus the inhabitants had made localized modifications to
the landscape through hunting, fishing and agricultural activities. From the first half of the 16th century up to the 19th century
rapid agricultural development took place, particularly with the
growth of sugar cane plantations, the exploitation of forests
and cattle raising. The third period, from the middle of the 20th
century onwards, was characterized by a rapid loss of forests;
an increase in relatively small farms growing sugar, plantain
and citrus; the development of hunting; and an increase in
urban areas (Leiva 1992).
In 1963 national reserves were created, covering a total land
area of 25 000 ha, in order to provide different levels of protection as recommended by the World Conservation Union (Leiva
1992, McNeely 1995) and to preserve the landscape. At present
these comprise an estimated 9% of the land in Cuba.
Ethnology
Cuba’s population is of varied origin and is a mixture not only
of races but also of cultures, with influences from Indoamerica,
Europe, Africa, French Haiti and Asia as well as post-war
immigrants from various countries. A short description of each
ethnic group follows.
Indoamericans The Taínos, of the Arawak tribes in the Orinoco area
of South America, were the most advanced group of early settlers.
During the conquest and colonization of Cuba, the aboriginal
population diminished and indigenous people from Central
America and the Caribbean, such as Yucatánecans, were brought
in. Agricultural practices such as “tumba y quema” (slash and
burn) for the cultivation of grains and maize, and “montones”
(hills) for roots and tubers are examples of the influence of the
indigenous cultures of Central and South America.
Europeans The majority of immigrants were Spanish and they
brought their Mediterranean implements and customs with
them. English people living in Havana also had some cultural
influence.
Africans The most important factor in the introduction of African slaves was the development of the sugar cane industry at
the end of 16th century (Pérez de la Riva 1977). African culture
has been one of the strongest influences on Cuban culture,
which can still be seen in the music, dance and religion.
French-Haitians French influence was considerable, particularly in
the eastern provinces where French immigrants built mansions
near their coffee plantations. Many African slaves came to Cuba
with their French masters from Haiti, and their descendants and
some elements of their culture still survive.
Asians After 1842 a great number of Chinese came to Cuba from
the English colonies of Barbados, Jamaica and Trinidad. Later
they were contracted directly from China to work in the agricultural sector and with them a new form of slavery commenced
consisting of heavy workloads for extremely low rewards. The
Japanese were a minority within the Asian immigrants and were
concentrated in relatively few areas. Their most important role
was in the development of fruit and vegetable crops.
Post-war minorities After the Second World War many European
immigrants came to Cuba, one group being the Swiss who
settled in specific areas and introduced advanced agricultural
technologies. In the first half of the 20th century many North
Americans also settled in Cuba and their influence can still be
seen in some food, cultural and linguistic customs.
Phytogenetic
According to Rodríguez et al. (1994), there are 809 endemic taxa of
wild flora, belonging to 55 families and 86 genera, related to the
cultivated plants in Cuba. One of the characteristics of this flora
is the presence of species complexes (a group of similar related
species), one example being Eugenia. The relative abundance of
such complexes is an indication of genetic plasticity and suggests an active geneflow among them. Species related to cultivated rice, such as Oryza perennis, or to sweet potato (Ipomoea spp.),
are other examples of this, as is the existence of an endemic
fruit-bearing species of Solanum, which could be useful for breeding purposes.
Knüpffer (1992) estimated that there are a total of 1045 taxa
of cultivated flora belonging to 117 families and 531 genera,
excluding woody trees and ornamental plants. The majority of
these species are cultivated as medicinal plants (432), fruit crops
(262), forage plants (173) or vegetables (99). These plants come
mainly from America but also from Europe, Indochina, Indonesia, Africa and the Indian subcontinent.
Socioeconomic
There are three basic agricultural production systems in Cuba:
(1) state production (state farms); (2) the cooperative sector,
including cooperatives that provide credit and services (CCS),
cooperatives for agriculture and cattle production (CPA), and
basic units of cooperative production (UBPC); and (3) the private sector. Agricultural production in home gardens in the
CPAs and UBPCs is dedicated to complementing food supplies
as staple foods are obtained directly from the state sector and
through internal trade networks.
Crops grown in CCSs and in private farms are exclusively
the property of the farmers who own the land and many families depend upon their produce. Farmers cultivate species and
varieties that are then passed on from one generation to another, sometimes over periods of more than 80 years. In general,
as they are adapted to poor agroclimatic conditions, these genotypes can be cultivated out of the main growing season and on
the poorest farmland.
Land use in extensive agricultural production systems may be
determined by only one crop; in such cases home gardens occupy
a very small area, poorly managed, and in general on the edges of
land. Home gardens used for vegetables, and root and tuber
production in the cooperatives are on better land than those in the
extensive systems and occupy larger areas, although they are
limited in size by an agreement with the cooperative. In urban
areas, home gardens are managed by families who then share the
produce. They may be located in peri-urban centres and sometimes include cultivation without soil (hydroponics).
12
Plant genetic diversity in home gardens:
proposed areas for in situ conservation
The results of the exploration mission showed that it was possible to find a large variety of cultivated plants, as well as related
wild species, in a number of different areas. Thirty localities with
different characteristics from 12 provinces were selected. Two
provinces were excluded due to their similarity with other selected areas close by.
Table 1 gives the areas selected, some of their characteristics,
the type of predominant landscape and the number of important species observed in each. Variability among the selected
areas can be observed between the regions where there is a
certain amount of agricultural development and those where
isolation permits the maintenance of traditional or underutilized
cultivars. Such areas are to be found throughout the country
and among all the principal landscapes. Some “conucos” can be
considered as living genebanks because of the variety of species
maintained and the variability within them. These should be
preserved for the future as a complement to ex situ strategies.
The list of the principal species observed in the “conucos” is
shown in Table 2. Species were classified into six groups according to their utilization by farmers. The group of roots and tubers
included 16 species, legumes and grains 15 species, while 29
species could be classified as vegetables. A further 20 species
were classified as fruit crops, 20 as medicinal, stimulants and
spices, and seven species were placed in the group of fibres and
ornamental plants. An analysis of the main crops in the areas
visited enabled the identification of 107 species maintained by
farmers in their own gardens. The variation within the home
gardens visited indicates their potential for the conservation of
plant genetic diversity.
A high level of infraspecific variability was observed in many
crops, based on morphological characters. For example, Phaseolus
vulgaris possessed wide variation for seed characters and different degrees of resistance or tolerance to diseases in open conditions. Variability was even greater in Phaseolus lunatus, a species
that is maintained as a perennial crop close to fences or in
abandoned maize fields and given little or no attention. Another interesting case was that of maize where pure races such
as ‘Criollo’, ‘Canilla’ and ‘Tuzón’ were only found in very isolated “conucos”. In the eastern region of Cuba it was also
possible to find primitive cultivars of flint maize with little
introgression from modern dent maize.
High infraspecific variability was also observed in vegetables,
such as in primitive cultivars of Lycopersicon esculentum and in a
related weedy form L. esculentum var. cerasiforme. We observed
variable populations of Capsicum annuum, C. chinense and C.
frutescens dispersed throughout the island and it was interesting
to note the high degree of cross pollination and morphological
similarities among some of these species, which made identification difficult (Barrios 1999).
It is common to find many species of fruit crops in “conucos”
as they provide food as well as shade for houses, crops, pasture
and roads. Infraspecific variability was considerable for roots
and tubers. For example, Manihot esculenta was observed in the
majority of the “conucos” visited, the primitive cultivars had a
wide variation in texture, colour and root fibre. Primitive and
variable cultivars of Ipomoea batatas, with wild related taxa, were
also found throughout Cuba (Fernández et al. 2000).
To summarize, crops such as bananas, plantains and common beans, with a range of species and types, appeared in most
of the “conucos”. Other crops such as maize and sweet potato
were also found, however, the most important vegetable crops
grown were tomatoes, pumpkins and the Alliaceae, as these are
extensively used in Cuban cooking. Medicinal plants have increased in importance in recent years and are given special care
by families. In all probability this phenomenon is influenced by
current socioeconomic factors, which have led to a scarcity of
medicines. Doctors play an important role in promoting the use
of plants for medicinal purposes.
Survey to characterize and monitor “conucos”
The utilization of farmers as local experts is important in the
areas explored. Many farmers have lived in the same place
sometimes for more than sixty years and know the farms as well
as their home gardens, including the crops grown and their
characteristics. The meetings with local experts, that took place
prior to exploring a region, proved very useful for this study.
Frequently farmers were recommended by the provincial delegations of the Ministry of Agriculture.
In general, Cuban farmers are kind and hospitable. When
arriving at a farmer’s home, the specialist described the Institution and the objectives of the research. During the discussions
and while completing the questionnaire, members of the families gave interesting and useful answers. The recommendations
and information given served as an introduction to other farmers allowing the whole region to be explored. Despite the current
trend of migration from the country to the cities (temporally or
definitively), farmers tend to maintain themselves on their land
for more than sixty years. This is one reason why a home garden
can be used for the in situ conservation of plant genetic resources.
The educational and vocational level of family members,
which were noted in the questionnaire, should be taken into
consideration as they can have a positive or negative influence
on the garden with respect to the diversity maintained and its
utilization. This information is also useful for predicting the
future of a “conuco”. Data on a family’s ethnic roots and the
economic position of the owner are also significant as these
factors are reflected in the choice of plants cultivated.
Some questions dealt with quantitative indices like garden
size, climatic characteristics and degree of pollution, while others were concerned with the organization of the garden. The
replies provided information on the structure, composition and
function of the garden. In many cases, “conucos” with similar
plant taxa, content and organization were managed by their
owners in completely different ways.
A large number of questions were asked about the plants
present in each “conuco” (Appendix 1-IV) in order to record
each species and obtain information on the types and varieties
of species present, and their relationship with wild or semi-wild
types. The final question asked was whether the farmer would
allow their “conuco” to be considered as a potential site for the
in situ conservation of the plants. In the majority of the cases the
answer was in the affirmative.
Table 1. Characteristics of the selected areas in different Cuban provinces, predominant landscapes and the
number of species observed in each area
Area
Province
Characteristics
Predominant
landscape
frequently Guane
Pinar del Rio
Fluvial marine plains
15
Viñales
Pinar del Rio
Pinar del Rio
Cocodrilo
Isla de la Juventud†
Karstic mountains and
valleys
Dissectional low
mountains
Karstic plains
20
Soroa
Influence of Spaniards,
tobacco cultivation
Influence of Africans, tobacco
cultivation in the valleys, timber
French influence, timber, tourism
Jucaro
Isla de la Juventud†
11
Guira de Melena
Havana
Sandy accumulative
alluvial plains
Karstic plains
Loma de Grillo
Havana
Highlands and hills
13
Stgo. de las Vegas
Havana City
Karstic plains
20
Alamar
Cienaga de Zapata
Havana City
Matanzas
Marine plains
Accumulative marshy
plains
11
13
Valle de Yumuri
Matanzas
Fluvial plains
12
Perico
Matanzas
Karstic plains
19
Highlands and hills
denuded
16
Karstic dissectional low
mountains
13
Low mountains denuded
karstic
Denuded and eroded
plains
Karstic plains
15
Moist highlands, hills
and mountains
14
Sandy accumulative
alluvial plains
Denuded eroded plains
Highlands and hills
denuded karstic
Low mountains denuded
16
Very moist middle mountains
Highlands and hills denuded
14
15
Accumulative alluvial plains
Low denuded mountains
14
15
Dissectional low mountains
15
Low denuded mountains
14
Accumulative eroded plains
16
Accumulative eroded plains
8
La Sierrita-San Blas Cienfuegos
Topes de Collantes
Sti. Spiritus
Banao
Sti. Spiritus
Zaza del Medio
Sti. Spiritus
Cevallos
Ciego de Avila
Palma City –
Sierra Cubitas
Camaguey
Omaja
Las Tunas
Velazco
Yaguajay
Holguin
Holguin
Pinares de Mayari
Holguin
Turquino
Gran Piedra
Santiago de Cuba
Santiago de Cuba
Guantanamo Valley
Yateras
Guantanamo
Guantanamo
Caujeri
Guantanamo
Yunque de Baracoa Guantanamo
Cajobabo
Guantanamo
La Maquina
Guantanamo
†
Havana Special Municipality
Ethnic (caimaneros), fishing
settlements in great isolation
Strongly influenced by ethnic minorities
(Japanese, North Americans)
Intense agricultural development, still
small farms, traditional crops and
high-yielding cultivars
Influence of ethnic minorities
(Yucatecan Indians), relative isolation
Relationship with foreign institutions,
rich in fruit gardens with unique
collections
Urban area in peripheral zone
Subsistence “conucos”, isolation,
national park, potential ecotourism
for rare-bird watching
Isolation, ecotourism and health
tourism development
African and Asiatic influence, sugar
cane dominates commercial production
Coffee plantations, integrated
programme for medicinal plants,
potential for ecotourism
Coffee and timber production, plant
introduction or acclimatization, health
and ecotourism
Area of small vegetable farms
especially from Canary Islands
(North Americans), production of
citrus fruit and vegetables
Influence ethnic minorities
(North Americans), cultivation of
citrus and other fruits
(North Americans, Europeans)
Agricultural development
An important place for Taíno
development. Obsolete cultivars
Highly microclimatic, potential
for ecotourism
Isolated region, national park
“Conucos” with rare and
obsolete cultivars
High temperature and salinity
Isolation, occupied mainly by
descendants of aboriginal groups
Horticultural zone., “conucos”
frequently feature obsolete and
rare cultivars
Isolated, coffee, coconut and
cacao cultivation
Isolated, agro-forestry systems and
potential for ecotourism
Coffee cultivation, some “conucos”
contain obsolete cultivars
No. of
species
12
15
20
13
16
18
15
12
14
Table 2. Main species found in Cuban “conucos” according to farmer’s utilization, their origin and the
frequency of the species observed in the 30 sites selected
Use/Species
Roots/tubers
Arracacia
xanthorriza
Beta vulgaris
Brassica napus
subsp. napus
Brassica rapa
Colocasia esculenta
Cyperus esculentus
Daucus carota
Dioscorea alata
Dioscorea bulbifera
Ipomoea batatas
Manihot esculenta
Maranta
arundinacea
Plectranthus
amboinicus
Raphanus sativus
Sechium edule
Xanthosoma
sagittifolium
Origin
Freq.
NW†
1
OW
OW
1
1
OW
OW
OW
OW
OW
OW
NW
NW
NW
2
3
2
1
3
2
10
8
3
OW
1
OW
NW
1
4
NW
7
Grain/legumes
Arachis hypogaea
NW
8
Cajanus cajan
Canavalia gladiata
Canavalia spp.
OW
OW
OW
5
1
1
Cicer arietinum
Helianthus annuus
Lablab purpureus
Mucuna pruriens
subsp. deeringiana
Pachyrhizus erosus
Panicum miliaceum
Phaseolus lunatus
Phaseolus vulgaris
Sorghum vulgare
Vigna ungiculata
Zea mays
OW
NW
OW
OW
2
5
2
3
NW
OW
NW
NW
OW
OW
NW
1
2
13
12
2
13
11
Use/Species
Origin
Freq
Medicinal/stimulant/spices
Aloe vera
OW
3
Use/Species
Origin
Freq.
Fruits/fruit trees
Averrhoa carambola
OW
1
Aloe spp.
Artemisia
abrotanum
Coffea arabica
Coriandrum sativum
Datura candida
Erygium foetidum
Laurus nobilis
Mentha spicata
Mentha spp.
Nicotiana tabacum
Ocimum basilicum
OW
OW
1
1
Annona reticulata
Annona muricata
NW
NW
1
1
OW
OW
NW
NW
OW
OW
OW
NW
OW
2
4
1
1
3
4
1
3
2
Annona squamosa
Carica papaya
Citrullus lanatus
Citrus aurantiifolia
Citrus aurantium
Citrus sinensis
Cocos nucifera
Cucumis melo
Mammea americana
NW
NW
OW
OW
OW
OW
OW
OW
NW
1
4
4
4
2
1
1
4
4
Ocimum
gratissimun
Ocimum temiflorum
Orthosiphon
aristatus
Petroselium crispum
OW
5
Manilkara zapota
NW
2
OW
OW
2
3
BO§
NW
4
1
OW
2
Mangifera indica
Melothria
guadalupensis
Muntigia calabura
NW
1
Saccharum
officinarum
Satureja hortensis
OW
1
Musa spp.
OW
9
OW
1
NW
2
Sesamum orientale
Zingiber officinale
OW
OW
5
2
Pasiflora
quadrangularis
Persea americana
Psidium guajabita
NW
NW
4
2
OW
6
Fibre/ornamentals
Catharanthus roseus
OW
2
NW
OW
OW
4
4
1
Gossypium hirsutum
Gossypium spp.
Justicia pectoralis
NW
NW
NW
1
1
5
OW
OW
OW
OW
3
1
8
9
Lippia alba
Luffa acutangula
Ruta chalepensis
NW
OW
OW
4
1
1
NW
OW
OW
OW
OW
OW
OW
1
1
1
3
3
1
1
OW
NW
NW
NW
OW
OW
OW
NW
OW
BO
NW
1
2
2
5
1
1
4
12
1
1
10
OW
OW
NW
1
1
1
Vegetables
Abelmoschus
esculentus
Allium canadese
Allium cepa
Allium cepa var.
aggregatum
Allium chinense
Allium fistulosum
Allium sativum
Allium spp.
Amaranthus spp.
Apium graveolens
Basella alba
Benincasa hispida
Brassica juncea
Brassica napus
Brassica napus
var. esculenta
Brassica spp.
Capsicum annuum
Capsicum chinense
Capsicum frutescens
Cimbopogon citratus
Cucumis dipsacus
Cucumis sativus
Cucurbita moschata
Lactuca sativa
Lagenaria siceraria
Lycopersicon
esculentum
Momordica charantia
Solanum melongena
Solanum ciliatum
NW = New World; OW = New World; BW = both New and Old World.
Identification of crops to characterize and monitor
the infraspecific diversity within and among the
“conucos”
It is important to identify the species and varieties that should
be targeted for in situ conservation. As a considerable number of
cultivated plant species posses high infraspecific variability, at
least on the basis of the morphological characteristics observed,
it was difficult to select crops for the characterization and
monitoring of variability among home gardens for use in the
next stage of the project.
When selecting crops of primary concern for further studies, the origin and diversity of the species, in relation to their
geographic position, were taken into account as well as ethnological and socioeconomic factors, the diversity found in
previous exploration missions, the frequency of their appearance in the “conucos” visited, the type of crops and their
utilization by farmers (Table 2). Using these criteria the following crops were selected: tomato (Lycopersicon esculentum),
maize (Zea mays), peanut (Arachis hypogaea), pumpkin (Cucurbita
moschata), common bean (Phaseolus vulgaris), lima bean (Phaseolus
lunatus), origanum (Ocimum gratissimum), sweet potato (Ipomoea
batatas), banana and plantains (Musa spp.), and cowpea (Vigna
unguiculata).
A morphological minimum descriptor list was prepared to
monitor each selected species for at least three years. It is proposed to add descriptors to these lists for each crop on an
individual basis. Flexibility in this aspect of the programme is
crucial as the frequency of monitoring each morphological character depends upon the crop itself. For example, a perennial
crop could be monitored monthly during flowering and the
fructification period, while an annual crop should be monitored
several times a month. This implies that a careful study is
needed prior to beginning work on in situ conservation.
Discussion
Developing an integrated plan for the in situ
conservation of plant genetic resources
Institutional aspects
A head coordinator is needed to develop a plan for the in situ
conservation of plant genetic resources and to liase with the
different institutions that come under the Ministries of Agriculture, Science, Technology, Environment and Higher Education. Field coordinators would then be selected at the level of
municipality and province. They would come under the direction of the local and municipal governments, or other organizations such as Non-governmental Organizations, and be responsible for the protection and conservation of the home
gardens in their areas.
At the same time, an education campaign is needed to
divulge information concerning the importance of the in situ
conservation of plant genetic resources. This should involve
farmers, local experts and people from local governments. Not
all institutions in a province/municipality will be involved with
the selected home gardens. Only institutions in, or near, the
selected home garden will be involved in the work and they will
choose, depending upon their means, which home gardens to be
involved with.
Integration with ex situ conservation, other in situ
conservation programmes and existing socioeconomic
programmes
After demonstrating the contribution of Cuban “conucos” to the
evolution of cultivated plants and the benefits of an in situ approach to conserving plant genetic resources, it will then be necessary to decide how best to preserve these agro-ecosystems. Both
programmes for ex situ conservation, such as genebanks or botanical gardens, as well as in situ conservation in protected areas,
should be connected with the rational utilization of natural resources and the conservation of primitive or obsolete cultivars in
home gardens. Ministries and universities with activities related
to the conservation and use of plant genetic resources should
work together in order to establish an effective monitoring system
for conserving plant genetic resources in home gardens. The
conditions needed for such activities exist, as there is good coordination at the different levels of government, between the state and
the municipalities and/or localities, and with farmers.
A network for in situ conservation in farmer’s “conucos”
should be integrated with the main socioeconomic and development programmes in the country in order to develop the sustainable use of plant genetic resources. One example is the
Cuban food programme, the main objective of which is to secure
an adequate supply of food by increasing food production
through the use of sustainable agriculture practices.
Another example is the health programme which advocates
a direct and close relationship between the doctor and the
community. One of its objectives is to promote the use of “green
medicine”. This approach was emphasized by Prain and Piniero
(1995) in a study on the community care of plant genetic
resources in the southern Philippines. Often farm families have
greater traditional knowledge and experience of the alternative
uses of medicinal plants than doctors. It should be possible to
increase the use of crop varieties, which have good yields, according to farmers, and to develop the necessary genetic base for
developing breeding and biotechnological programmes, and
other scientific research to identify and broaden the use of the
different varieties of medicinal plants.
Long-term monitoring of the variability in home gardens
could be carried out by the farmers themselves, assisted by local
experts from protected areas or provincial environmental units,
in accordance with the national integrated strategies. A structured “conuco” network would contribute to preserving plant
varieties and improve the sustainable increase of agricultural
production in the country by means of the rational use of plant
genetic resources with a low ecological cost. This would also
help to preserve valuable traditional practices and cultural values in farm communities. The use of home gardens to conserve
in situ the many varieties of cultivated species present in Cuba
can be a key complementary approach to the ongoing conservation strategies and socioeconomic programmes.
Acknowledgements
We wish to acknowledge the support of the IPGRI for these
studies and particularly the technical support of Dr Toby
Hodgkin and Dr Pablo Eyzaguirre. We wish also to thank all the
people that contributed to the revision of the manuscript.
16
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“conuco”: a perspective environment for evolution and in situ
conservation of plant genetic resources in Cuba. Genet. Resour.
Crop Evol. 39:9-22.
Esquivel, M. and K. Hammer. 1994. The “conuco”: a perspective
environment for the evolution and in situ conservation of
plant genetic resources in Cuba. Pp. 694-702 in “... y tienen
faxones y fabas muy diversos a los nuestros ...”. Origin,
Evolution and Diversity of Cuban Plant Genetic Resources,
Vol. III (K. Hammer, M. Esquivel and H. Knüpffer, eds.).
Inst. für Pflanzengenetik und Kulturpflanzenförschung,
Gatersleben, Germany.
Fernández, L., A.A. Rodríguez Nodals, N. Companioni, O.L.
Parrado, J. Saurín, Z. Fundora Mayor, A. Cairo and P. Sánchez.
(2000). Colecta de recursos fitogenéticos en la provincia de
Camaguey. Rev. Jardín Botánico Nacional (in press).
Franco, J.L. 1975. La diaspora africana en el Nuevo Mundo. Ed.
Ciencias Sociales. La Habana, Cuba.
Hammer, K., M. Esquivel and H. Knüpffer. 1992. Inventory of the
cultivated plants. Pp. 213-454 in “... y tienen faxones y fabas
muy diversos a los nuestros ...”. Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. II (K. Hammer,
M. Esquivel and H. Knüpffer, eds.). Inst. für Pflanzengenetik
und Kulturpflanzenforschung, Gatersleben, Germany.
Hodgkin, T. 1995. The role of farmers in maintaining biodiversity.
Pp. 92-93 in In Situ Conservation and Sustainable Use of
Plant Genetic Resources for Food and Agriculture in Developing Countries. Report of DSE/ATSAF/IPGRI Workshop,
Bonn-Rottgen, Germany.
Knüpffer, H. 1992. The database of cultivated plants of Cuba.
Pp. 202-212 in “... y tienen faxones y fabas muy diversos a los
Genetic Resources, Vol. II (K. Hammer, M. Esquivel and H.
Knüpffer, eds.). Inst. für Pflanzengenetik und
Leiva, A. 1992. In situ conservation of wild plants. Pp. 174-192 in
“... y tienen faxones y fabas muy diversos a los nuestros ...”.
Origin, Evolution and Diversity of Cuban Plant Genetic Resources, Vol. I (K. Hammer, M. Esquivel and H. Knüpffer,
eds.). Inst. für Pflanzengenetik und Kulturpflanzenforschung,
McNeely, J.A. 1995. The role of protected areas for conservation
and sustainable use of plant genetic resources for food and
agriculture. Pp. 27-42 in In situ Conservation and Sustainable
Use of Plant Genetic Resources for Food and Agriculture in
Developing Countries. Report of DSE/ATSAF/IPGRI Workshop, Bonn-Rottgen, Germany.
MINAG - Ministerio de la Agricultura. 1991. Plan de Acción
Forestal para Cuba. Documento Base, Ministerio de la
Agricultura, La Habana, Cuba.
Niñez, V. 1986. El huerto casero: un salvavidas? Ceres 112:31-36.
Ortiz, F. 1975. Los negros esclavos. Ed. Ciencias Sociales, La
Habana, Cuba.
Perera, A. 1986. Panorámica de las áreas protegidas en la
República de Cuba. Conservando el patrimonio natural de la
región neotropical. Proc. of the 27th Working Season of the
IUCN Commission on Natural Parks and Protected Areas,
Bariloche, Argentina.
Perera, A. and P. Rosabal. 1986. Las áreas protegidas en Cuba.
Silvestres 2:13-17. FAO Regional Office for Latin America
and the Caribbean, Santiago, Chile.
Pérez de la Riva, J. 1977. Cuántos africanos fueron traídos a
Cuba? Ed. Ciencias Sociales, La Habana, Cuba.
Prain, G.D. and M.C. Piniero. 1995. Community curatorship of
plant genetic resources in southern Philippines, preliminary
findings: towards a partnership. Proc. of an International
Workshop on User Participation in Plant Genetic Resources
Research and Development. Alaminos, Pangasinan, Philippines
Ragione, I. Dalla and P. Perrino. 1995. On-farm conservation of
fruit trees and the informal sector in Italy. Pp. 166-175 in
Integration of Conservation Strategies of Plant Genetic Resources in Europe. Proc. of an International Symposium of
Plant Genetic Resources in Europe. Gatersleben, Germany.
Rivero de la Calle, M. 1966. Las culturas aborígenes de Cuba. Ed.
Universitaria, La Habana, Cuba.
Rodríguez, M., F. Cejas, A. López and L. Montes. 1994. The wild
relatives of cultivated plants in the flora of Cuba. Pp. 570-577
in “... y tienen faxones y fabas muy diversos a los nuestros
...”. Origin, Evolution and Diversity of Cuban Plant Genetic
Resources, Vol. III (K. Hammer, M. Esquivel and H. Knüpffer,
eds.) Inst. für Pflanzengenetik und Kulturpflanzenforschung,
Salazar, R. 1996. The role of farming communities in plant genetic
resources conservation and development. Pp 170-183 in Plant
Genetic Resources in Vietnam. Proc. of a National Workshop,
Hanoi, Vietnam, 1995. Agriculture Publishing House, Hanoi,
Viet Nam.
Salinas, Er. and Ed. Salinas. 1992. Features of the nature and
landscapes. Pp. 174-192 in “... y Tienen Faxones y Fabas Muy
Diversos a Los Nuestros ...”. Origin, Evolution and Diversity
of Cuban Plant Genetic Resources, Vol. 1 (K. Hammer, M.
Esquivel and H. Knüpffer, eds.). Inst. für Pflanzengenetik
und Kulturpflanzenforschung, Gatersleben, Germany.
Santana, E. 1991. Nature conservation and sustainable development in Cuba. Conserv. Biol. 5:13-16.
Valdés, S. 1978. Indoamericanos no arawakos en el español
hablado de Cuba. Ed. Ciencias Sociales, La Habana, Cuba.
Valdés, S. 1986. La evolución de los indoamericanos en el español
hablado en Cuba. Ed. Ciencias Sociales, La Habana, Cuba.
Appendix 1. Questionnaire used in the pilot project for the in situ conservation of
cultivated plant variability in home gardens
I.
1.
2.
3.
4.
5.
6.
7.
8.
9.
NAME AND LOCALIZATION OF THE STUDY AREA (data collected from the area where the home garden is localized)
Name of the area
Locality
Province
Municipality
Geographical situation
General characteristics of flora and fauna
Pollution
Accessibility of the area
State of main communications
II. CHARACTERISTICS OF THE FARM FAMILY (data provided by the owner)
1. Name
2. Sex
3. Colour of skin
4. Place of birth
5. Date of birth
6. When did you arrive in this place?
7. Who lived here when you came?
8. Do you remember from which country your family came from?
9. Do you think you will leave here? If so why?
10. What is your level of education?
11. What is your civil state?
12. Family details (number of persons, age, sex and scholarship)
13. How many members of the family are economically dependent upon you (how many are economically unproductive)?
14. What is your main occupation?
15. What is your occupation (if your main occupation is not the home garden)?
III. DATA ON THE SPECIFIC AREA OCCUPIED BY THE HOME GARDEN
1. Name of the home garden or the house in order to identify the locality.
2. Size of the area (ha)
3. Geographic localization (using GPS) and the distance from a well-known area.
4. Topography
5. Hydrography
6. Soil type (texture, drainage, fertility and humidity)
7. Precipitation/year
8. Yearly temperature
9. Contamination
10. How far is the home garden from your home?
11. In which state did you find this place?
12. Type of home garden according to the property (specify organization system)
Private ____
State ____
Both ____
13. Which members of your family or other persons work in your home garden? What activities do they carry out?
14. How many hours per person are dedicated to working in the garden per week and per month?
15. Do you have domestic animals? If yes what type of animals?
a. Birds _____
b. Bees ____
c. Goats ____
d. Rabbits ___
e. Horses ____
f. Ovine ____
g. Pigs _____
h. Cows _____
Other ______
Why are you raising the animals (write the letter according to the above)?
Subsistence ____
Sell ____
Both ____
16. Do you remember when this land started to be cultivated?
17. Why do you cultivate this land?
Subsistence ___
Sell ___
Both ___
18. Do you have special plants in your home garden, which and why?
19. Do you have only this garden?
18
20. How did you learn to prepare and take care of your home garden?
21. What are the main plants grown in your garden?
22. Who are you growing the plants for?
23. Which of your family’s food needs can be met by the produce of your home garden?
24. How do you obtain products that you do not produce in your garden?
25. What are the main problems that you face in your home garden?
Water ___
Diseases/pests ___
Seeds ___
Equipment ___
Inputs ___ Fertilizers/pesticides ____
Diversity of GR ___
Other (specify) ___
How do you supply the inputs you need?
Buy ____
Trade ____ Exchange ____ Other (specify) ____
26. Do you receive help from the State? If yes for what?
Fertilizer ____ Pesticides ___ Seeds ___
Work equipment ___
Other (specify) ___
IV. SPECIFIC DATA ON PLANTS GROWN IN HOME GARDEN
1. Species
2. Common name
3. Genetic status
Wild ___
Weed ___
Landrace ____ Breeding cultivar ____
4. When and how did you obtain this plant?
5. What is the main reason for growing this species or variety?
6. Did you cultivate another variety of this plant? If you have stopped why did you not continue?
7. Phenology of the crop
Other (specify) ____
———————————————————————————————————————————
Month
1
2 3 4 5 6 7 8 9 10 11 12
———————————————————————————————————————————
Sowing
———————————————————————————————————————————
Harvest
———————————————————————————————————————————
8. What is the use of this plant?
9. How do you reproduce this plant?
10. Do you produce your own seeds?
11. How do you harvest the plant?
By hand ____
Mechanized ____
Both ____
12. How do you prepare the land?
By hand ____
Mechanized ____
With animals ____
13. Water management
Dryness ____
Partial irrigation ____
Irrigation (specify) ____
14. Has the crop been affected by pests or diseases? How do you prevent them?
15. How do you control weeds?
By hand ____
Chemicals ____
Not necessary ____
16. Do you fertilize this crop? Which type do you use?
Chemical ____
Organic ____
Both ____
17. How do you select the material for the next sowing?
18. How do you conserve/store the harvested material for propagation?
Paper bag ____
Paper box ____
Crystal bottle ____
Cloth Bag ____
Soil ____
Nylon bag ____
V.
1.
2.
3.
GENERAL QUESTIONS
How do you see the future of your home garden? Will someone from your immediate family keep it up after you?
What will be the main effect?
Would you like to cooperate with us in a long-term project to monitor the potential of your home garden to preserve valuable plants?
EVALUATION
1. Main observed potentiality
2. Main observed restrictions
3. Evaluation
Date:
Evaluators:
Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No. No.
123:123
19 - 19
22
ARTICLE
Ethnobotanical testimony on the ancestors of
cassava (Manihot esculenta Crantz subsp. esculenta)
Antonio C. Allem
Embrapa Recursos Genéticos e Biotecnologia, CP 02372, 70849-970 Brasília, DF, Brazil.
Summary
Résumé
Resumen
The hypothesis that cassava has living
wild ancestors was advanced in 1987.
Some authors who doubted the wild
condition of the populations reported
have suggested that these could be feral
cassava. Over the years, an ethnobotanical record of the relationship between
humans and the wild ancestors of cassava has been compiled providing
strong evidence for the wild character of
the material investigated. This study reports on the most important findings
which are: (1) the progenitor did not escape from plantations, (2) the roots are
mostly woody inedible and toxic, (3) the
leaves are toxic to livestock, (4) the plant
is widely regarded as a weed, and (5) the
common name assigned to the plant reflects its wild condition.
L´hypothèse sur léxistence de láncêtre
sauvage vivant du manioc fut proposée
à lánnée de 1987. Quelsques auteurs
mirent en doute l´état sauvage de populations étudiées, suggérant quélles pouvaient être du manioc cultivé. Pendant
les années, un approche ethnobotanique
sur les raports entre l´homme et láncêtre
sauvage du manioc fut compilé. Cet approche presente une forte évidence du
caractère sauvage des plantes. Les plus
importantes trouvailles faites sur le terrain furent : 1. Láncêtre nést pas un
évadé des plantations ; 2. Les racines sont
presque entièrement ligneuses, immangeables et toxiques ; 3. Les feuilles
sont toxiques au bétail ; 4. La plante est
considérée comme une mauvaise herbe ;
5. Le nom commun attribué à la plante
évoque sa condition sauvage.
La hipótesis sobre la existencia de un ancestral silvestre vivo de la yuca fue propuesta en 1987. Algunos autores pusieron en duda el estado silvestre de las
poblaciones estudiadas, sugeriendo que
ellas podrían ser yuca cultivada. Durante
los años, un abordaje etnobotánico sobre las relaciones entre el hombre y el
ancestral silvestre de la yuca fue compilado. Ese abordaje presenta una fuerte evidencia del carácter silvestre de las plantas. Los más importantes hallazgos
hechos en el campo fueran: 1. El ancestral
no es un evadido de las plantaciones; 2.
Las raíces son casi por completo leñosas,
incomibles y tóxicas; 3. Las hojas son tóxicas al ganado; 4. La planta es considerada como una mala hierba; 5. El nombre
común asignado a la planta evoca su
condicíon silvestre.
Ethnobotanical testimony on
the ancestors of cassava
(Manihot esculenta Crantz
subsp. esculenta)
Le témoignage ethnobotanique
sur l’ancêtre du manioc
subsp. esculenta)
El testigo etnobotánico sobre
el ancestral de la yuca
subsp. esculenta)
Key words: Ancestor, cassava,
Manihot esculenta Crantz subsp.
flabellifolia (Pohl) Ciferri, M.
esculenta Crantz subsp. peruviana
(Muell. Arg.) Allem
Introduction
Ethnobotany studies the biological, economic and cultural interrelationships between human beings and plants; more specifically, this discipline is concerned with knowledge about plants
and their use by society. In the case of Manihot, researchers have
long been familiar with the fact that wild relatives of cassava are
known to South American rural communities (Pax 1910; Rogers
1963; Rogers and Appan 1973). Cassava is known to have several
common names (Rogers and Fleming 1973; Lancaster et al. 1982).
Traditionally, the vernacular names cited by writers for the wild
species were mostly taken from herbarium labels. However, more
in-depth information from agriculturalists and collectors of wild
species is conspicuously missing from these.
The most common Portuguese name found in the literature
for wild relatives of cassava is “mandioca-brava”. The name
“mandioca-brava” (mandioca-braba is an orthographic variant) is found in Portuguese-speaking Brazil as well as in other
South American regions where Spanish, French, Dutch or English are prevalent. Rogers and Appan (1973) documented a
large variety of names for wild species of cassava but again,
most of these derive from herbarium labels and few are accompanied by more substantial ethnobotanical data. In contrast to
shrubs and small trees, which generally go under the name wild
cassava, herbs are distinguished with peculiar names, often in
the diminutive form and related to the habits of the plant. For
example, the name “mandioquinha-do-campo” given to M.
hassleriana in southern Brazil is an allusion to its habit of invading
soyabean plantations.
Attributing names to plants establishes some sort of relationship between people and plants and shows that people are
familiar with them to some extent. The history of sweet potato
shows how social traditions can be a determining factor in the
proliferation of names applied to crops (de la Puente et al. 1996).
However, in respect of cassava, the names given to plants are
not anecdotal as the terms used are invariably associated with
an economic peculiarity of the plant (e.g. agronomic property of
the root, invader of crop plantations, etc.).
This study reports on the interaction discovered to exist between agriculturalists and the ancestors of cassava, viz. Manihot
esculenta Crantz subsp. flabellifolia (Pohl) Ciferri and M. esculenta
Crantz subsp. peruviana (Muell. Arg.) Allem. The aim is to record
the vernacular historiography and the ethnobotanical knowledge
related to the ancestors of cassava. This article is also concerned
with the assumptions made about the origin of the materials.
Three authors (Bretting 1990; Heiser 1990; Bertram 1993) have
suggested that feral cassava may have been the progenitor of the
crop and that the populations described as wild by Allem (1987)
20
could have spread from cassava plantations. Subsequent publications (Allem 1994a, 1999, 2000) upheld the 1987 interpretation of
the botanical origin of cassava and reaffirm the view that these
genetic resources equate with the wild primary genepool of cassava. The purpose of this communication is to further strengthen
the hypothesis that the materials are wild.
Informal field interviews were conducted in areas of the Brazilian neotropics, particularly in western Amazonia. These mostly
took place along the sides of the road whenever local residents
showed an interest in the collecting activity or crossed the
collecting area on foot or on bicycle. Three basic questions were
asked of all the local residents that the team met: (1) “Do you
know this plant?”, (2) “Do you know its name?”, (3) “Is it wild
or cultivated by local people?”. Normally, those in transit quickly
answered the questions and proceeded on their way. However, a
few showed greater curiosity and stood by to observe the work of
the collecting team. In these cases people expanded on their
earlier answers and volunteered additional information on the
plant. On such occasions the team took the opportunity to ask a
few additional questions of the agriculturalists, the most important of which were: (4) “Is the plant frequent in the region?” (5)
“Is the plant harvested for its roots?” (6) “Is the plant restricted
to roadsides?”.
Table 1 lists the municipalities where the interviews took
place, the number of local people that took part in the survey
and their replies to the three standard questions. The remarks of
those who further expanded on their replies were recorded in
their native tongue and are given, together with a translation, in
Table 2. The field survey was carried out from 1986 to 1996,
most work being done in 1992 and 1993. The herbarium vouchers of the author are deposited at the Embrapa Recursos
Genéticos e Biotecnologia Herbarium (CENARGEN) in Brasília.
Most of the testimonies were recorded on sheets of paper as
the comments were inappropriate for the type of notebook being
used. This explains why some of the quotations given here are
missing from the respective herbarium labels.
Discussion
The first interviews took place in 1986 while collecting in the
Brazilian Amazonian states of Mato Grosso and Rondônia. Simultaneously, some data was obtained in the central state of
Goiás and in the northwestern Amazonian state of Acre. All the
people interviewed and listed in Tables 1 and 2 answered the
questions about the ancestors of cassava to some extent. This
showed that all were familiar with the plant in question, no
matter whether the plant was found as a ruderal or bordering the
woods. No one seemed to doubt the wild character of the materials. One aspect of the plant that drew the attention of the team
was the fact that although inedible to humans, a number of
people reported that armadillos and wild pigs feed on the roots.
In three locations the ancestors of cassava were described as a
weed. When João Xavier, an agriculturalist living at Colônia Bela
Vista in the state of Mato Grosso was interviewed on 14 May
1992, he could not explain why wild Manihot was found growing
on his plantation among papaya, banana trees and a few plants
of cultivated cassava as well as common beans. It took considerable time for the team to infer what
had happened, i.e. wild cassava
Table 1. Replies to three standard questions about the ancestor of cassava:
(1) Do you know this plant? (2) Do you know the name of this plant? (3) Is this
had sprouted back from dormant
plant wild or cultivated in the area?
rootstocks left underground when
the humid forest was cleared. This
Municipality
State
Date
Voucher No. of
Reply†
also explained the find of two exAgriculturalists
amples of the subspecies peruviana
Niquelândia
Goiás
4.3.86
3469
1
y; mb; w
on a derelict maize plantation at
Pontes e Lacerda
Mato Grosso
12.5.86
3530
1
y; mb; w
Colônia Bela Vista. Voucher 4033
Cacoal
Rondônia
14.5.86
3547
1
y; mb; w
documents the visit made on 8
Ariquemes
Rondônia
18.5.86
3571
1
y; mb; w
June 1992 to the farm of Gentil
Vila Rica
Mato Grosso
26.5.86
3605
1
y; mb; w
Rodrigues. There the team found
Pontes e Lacerda
Mato Grosso
13.11.91 3980
1
y; mb; w
Lambari
Mato Grosso
23.5.92
3987
1
y; mb; w
shrubs up to 2 m tall of the subspeLambari
Mato Grosso
23.5.92
3988
1
y; mb; w
cies peruviana growing together with
Pontes e Lacerda
Mato Grosso
24.5.92
3992
1
y; mb; w
maize plants, squashes and other
Pontes e Lacerda
Mato Grosso
8.6.92
4033
1
y; mb; w
minor crops. The morphology of
Lambari
Mato Grosso
3.6.93
4107
3
y; mb; w
the plants resembled that of cultiLambari
Mato Grosso
3.6.93
4108
1
y; mb; w
Lambari
Mato Grosso
3.6.93
4109
1
y; mb; w
vated cassava and the plantation
Lambari
Mato Grosso
3.6.93
4110
1
y; mb; w
was encircled by the highly deLambari
Mato Groso
3.6.93
4111
1
y; mb; w
graded remnants of the tropical
Lambari
Mato Grosso
3.6.93
4112
1
y; mb; w
rainforest. As in the previous case
Pontes e Lacerda
Mato Grosso
7.6.93
4117
2
y; mb; w
mentioned, it became evident that
Pontes e Lacerda
Mato Grosso
8.6.93
4121
1
y; mb; w
Porto Velho
Rondônia
11.6.93
4140
1
y; mb; w
the wild cassava plants growing in
Porto Velho
Rondônia
11.6.93
4141
1
y; mb; w
the plantation originally grew in
Porto Velho
Rondônia
11.6.93
4142
1
y; mb; w
the rainforest and had regrown
Guajará-Mirim
Rondônia
11.6.93
4144
1
y; mb; w
from dormant rootstocks after the
Rio Branco
Acre
14.6.93
4149
1
y; mb; w
plot had been cleared to make
†
y = yes; mb = mandioca brava; w = wild.
room for agriculture.
Table 2. Replies expanding on the ethnobotanical knowledge of the ancestor of casssava
Municipality
State
Niquelândia
Goiás
Rondonópolis
Voucher
No. of
agriculturalists
Reply
Translation
4.3.86
3467
2
Mato
Grosso
Mato
Grosso
8.5.86
3515
1
9.5.86
3516
1
Pontes e
Lacerda
Pontes e
Lacerda
Mato
Grosso
Mato
Grosso
12.5.86
3531
1
12.5.86
3532
1
Ninguém come; em outras
áreas faz-se farinha e polvilho
dela, mas não aqui.
Mandioca-brava. A raiz é
lenhosa e não é comida.
Mandioca-brava. A gente não
come porque é tóxica e a raiz
é um pau.
Mandioca-brava. O tatu come
a raiz dela.
Mandioca-brava. É abundante
na mata. Vem fácil quando
desmata. Ninguém planta.
Catéte (porco-do-mato) come
a raiz. É praga.
Cacoal
Rondônia
14.5.86
3545
2
Cacoal
Rondônia
14.5.86
3546
1
Ariquemes
Rondônia
18.5.86
3572
1
Lacerdinha
Mato
Grosso
13.11.91
3979
1
Pontes e
Lacerda
Mato
Grosso
24.5.92
3991
2
Lacerdinha
Mato
Grosso
24.5.92
3994
1
É nativa. Dá raiz, mas não
presta. Na minha lavoura de
milho tá assim dela.
Ariquemes
Rondônia
27.5.92
4009
1
Porto Velho
Rondônia
28.5.92
4012
1
No Ceará nós conhecemos
ela por ‘maniçoba’.
Esta mandioca tem muito no
mato. Não dá raiz.
Lacerdinha
Mato Grosso 8.6.92
4033
1
O gado come desta mandioca
-brava se a pastagem não
está boa. O animal não digere,
empanzina e morre.
Lambari
Mato Grosso 9.6.92
4034
1
Lambari
Mato Grosso 9.6.92
4035
5
A turma aqui chama ela de
mandioca-brava.
Todos riram à menção de que
podia ser mandioca cultivada.
Souza disse que conhecia a
planta e que havia muito dela
nas matas próximas, de
propriedade de Dr. Armando.
Lambari
Mato Grosso 14.5.92
?
1
It is not eaten; in other
areas flour and ‘polvilho’ are
made of it, but not here.
Wild cassava. The root is
woody and it is not eaten.
Wild cassava. We do not
eat it because it is toxic and
the roots are very hard.
Wild cassava. The armadillo
eats the roots.
Wild cassava. It is abundant
in the woods. It sprouts back
easily when deforestation
takes place. Nobody plants
it. Catéte (wild pigs) eat the
roots. It is a weed.
Wild cassava. It is a serious
weed in the area.
Wild cassava, bushwood
cassava. When the forest is
fallen, the plant sprouts back
vigorously. It is highly toxic.
Pigs die if fed on leaves. It is
a weed. In 1982 my father
planted some stakes and the
harvest produced roots of
fair quality, from which only
flour was made since the
root is toxic. A good harvest
was obtained within a year.
The plant propagates well
through stakes.
Wild cassava. It occurs in
the woods. It is fond of rocky
outcrops. The root only
produces ‘small potatoes’.
It is wild cassava. It is not
cultivated. It is a native of the
region. Nobody plants it. The
roots are minuscule.
It is wild cassava. It is not
planted here. It is a weed.
There is plenty of it around.
If you prune it back, it
sprouts back vigorously.
It is native. It produces roots
but they are not good. There
is lots of this wild cassava in
my maize plantation.
In Ceará we call it ‘
maniçoba’.
There is plenty of this
cassava in the bush wood.
The plant does not produce
edible roots.
Cattle eat wild cassava if
the pasture is not good. The
animal does not digest it,
the stomach swells and the
animal dies.
Folks know it by the name
mandioca-brava
All laughed at the mention
that the plant could be
cassava. Souza said he
knew the plant and that
there was plenty of it in the
nearby woods of the estate
of Dr. Armando.
If you cut it back, it sprouts
back.
Rondonópolis
Date
Mandioca-brava. É praga
séria na região.
Mandioca-brava;
mandioca-do-mato. Quando
corta a mata, aí é que ela vem
furiosa. Altamente tóxica.
Folhas dadas a porcos,
matam-nos. Em 1982 o pai
plantou estacas dela e deu
raiz boa, de onde fizemos
farinha, porque a raiz é tóxica.
Colhemos com um ano de
plantada. Pega bem de estaca.
Mandioca-brava. Dá nas
matas. Gosta mesmo é de
afloramentos rochosos. A raiz
só dá ‘batatinhas’.
É mandioca-brava. Não é
cultivada. É nativa da região.
Ninguém planta. Dá uma
raizinha assim.
É mandioca-brava. Não
plantam aqui. É praga. É o que
mais tem. Roçou, ela vem”
Quando roça, ela vem.
22
Municipality
State
Date
Voucher
No. of
agriculturalists
Reply
Translation
Lacerdinha
Mato Grosso
24.5.92
?
1
Tá atrás de mandioca? Tá
pegando mandioca? Esta não
presta, não é mandioca.
Lambari
Mato Grosso
10.6.92
4037
1
Dá pau. Não presta.
Lambari
Mato Grosso
10.6.92
4037
1
Anápolis
Goiás
18.5.92
4047
1
É mandioca-brava. É nativa.
O catitu come. Dá uma
raizinha assim.
Os fazendeiros caçam
implacavelmente a mandioca
porque as folhas são tóxicas
ao gado. Se os animais
comem folhas frescas, os
estômagos incham e o animal
morrre. As folhas da mandioca
cultivada não são tóxicas.
Hinterlândia
Goiás
18.5.92
?
1
Isto é mandioca-brava. Não
produz raízes. Nativa da região.
Não é fugida de plantações
de mandioca ao redor.
Rio Branco
Acre
14.6.93
4149
1
Faz mal de comer. É selvagem.
Are you after cassava? Are
you collecting cassava?
This is rubbish, it is not
cassava.
The roots are hard, it is no
good.
It is wild cassava, it is native.
Wild pigs eat the roots. It
produces a minute root.
Farmers search for its
ancestor implacably
because the leaves are
toxic to cattle, their
stomachs swell and they
die if they eat fresh leaves.
In contrast, the leaves of
the domesticated variety
are not toxic.
This is wild cassava. It
does not yield roots. It is
native to the area and it
has not escaped from
nearby cassava plantations.
It is no good to eat it is wild.
Three young boys (voucher 4107) laughed at the idea that
“mandioca-brava” could be the ancestor of cultivated cassava.
The same type of reaction occurred in Colônia Bela Vista, and in
the municipality of Lambari on a plot of land donated by the
federal government and shared among 20 families. When the
team asked about the subspecies peruviana, the wife of the landless José Lopes de Souza, a migrant from the Brazilian state of
Minas Gerais, and three visiting neighbours, laughed at the
mention of feral cassava. Agriculturalist José Lopes de Souza,
39, offered to take the collecting group to an area where there
was still plenty of this wild cassava (see voucher 4035). The
results of this exploratory mission are reported in Allem (1994b).
A particularly enlightening view of the wild state of the
material took place in the district of Lacerdinha on 24 May 1992,
at km 323 of BR-174 highway (see Table 2). A 12-year-old boy
who saw the team collecting seeds of the subspecies peruviana
stopped and dismounted from his bicycle thinking that the
team were collecting the plant by mistake (dialogue given in
Table 2). Similarly, two men awaiting a bus on 24 May 1992, at
km 208 of BR-174 highway, eventually intervened after 20 min
of watching the team as they were unable to understand why
seeds of the subspecies peruviana were being collected from along
the embankment (see voucher 3991 in Table 2).
A final revealing episode on the wild character of the plant
occurred 63 km NW of the municipality of Ariquemes on BR-364
highway (voucher 4009, Table 2). A migrant from the Brazilian
northeastern state of Ceará, walking along the road, addressed
the team saying “In Ceará we know it as maniçoba”. This
testimony was relevant because it strengthened the hypothesis
of the wild nature of the plant by associating its morphology
with that of wild relatives from northeast Brazil. In northeast
Brazil, a woody species of Manihot living in the xerophilous
vegetation known as Caatinga, is called maniçobas.
To sum up, the rich folklore and wisdom of the inhabitants
of the Brazilian neotropics indicate that wild relatives of cassava
still abound.
References
Allem, A.C. 1987. Manihot esculenta is a native of the neotropics.
Plant Genet. Resour. Newsl. 71:22-24.
Allem, A.C. 1994a. The origin of Manihot esculenta Crantz
(Euphorbiaceae). Genet. Resour. Crop Evol. 41:133-150.
Allem, A.C. 1994b. Manihot germplasm collecting priorities. Pp.
87-110 in Report of the First Meeting of the International
Network for Cassava Genetic Resources. International Crop
Network Series No. 10. IPGRI, Rome, Italy.
Allem, A.C. 1999. The closest wild relatives of cassava (Manihot
esculenta Crantz). Euphytica 107:123-133.
Allem, A.C. 2000. The origins and taxonomy of cassava (Manihot
esculenta Crantz subspecies esculenta). In Cassava: Biology,
Production and Utilization (R.J. Hillocks, M.J. Thresh and A.C.
Bellotti, eds.). CABI International, Oxford, UK (in press).
Bertram, R.B. 1993. Application of molecular techniques to genetic
resources of cassava (Manihot esculenta Crantz, Euphorbiaceae):
interspecific evolutionary relationships and intraspecific characterization. PhD thesis, University of Maryland, U.S.A.
Bretting, P.K. 1990. New perspectives on the origin and evolution
of New World domesticated plants: introduction. Econ. Bot.
(Suppl.) 44:1-5.
Heiser, C.B., Jr. 1990. New perspectives on the origin and evolution of New World domesticated plants: summary. Econ.
Bot. (Suppl.) 44:111-116.
Lancaster, P.A., J.S. Ingram, M.Y. Lim and D.G. Coursey. 1982.
Traditional cassava-based foods: survey of processing techniques. Econ. Bot. 36:12-45.
Pax, F. 1910. Euphorbiaceae-Adrianeae. In Das Pflanzenreich,
IV. (A. Engler, ed.). 147.II. 44:1-111.
Puente, de la F., D.F. Austin and J. Díaz. 1996. Common names
of the sweet potato (Ipomoea batatas) in the Americas. Plant
Genet. Resour. Newsl. 106:13-15.
Rogers, D.J. 1963. Studies of Manihot esculenta Crantz and related
species. Bull. Torrey Botanical Club 90:43-54.
Rogers, D.J. and Appan, S.G. 1973. Manihot and Manihotoides
(Euphorbiaceae), a computer-assisted study. Flora Neotropica,
monograph no. 13. Hafner Press, New York, USA.
Rogers, D.J. and H.S. Fleming. 1973. Monograph of Manihot
esculenta Crantz. Econ. Bot. 27:1-114.
Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No. No.
123:123
23 - 23
27
ARTICLE
Reincorporación del fríjol carauta (Phaseolus lunatus
L.) a la agricultura tradicional en el resguardo indígena
de San Andrés de Sotavento (Córdoba, Colombia)
Gustavo Ballesteros P.¹, Asterio Torres G.²* y Martha Barrera³
¹ Universidad de Córdoba, Montería, Colombia
² Instituto Técnico Industrial y Agropecuario de Campeche, Baranoa, Atlántico Colombia. Email: [email protected]
³ Unidad Municipal de Asistencia Técnica, Agropecuaria (UMATA), Polonuevo, Atlántico, Colombia
Resumen
Résumé
Summary
Cuatro especies de Phaseolus (P. vulgaris,
P. lunatus, P. Coccineus y P. acutifolius)
han proporcionado, desde tiempos prehispánicos, alimento a los pueblos de
América, que las convirtieron, junto con
el maíz, en su dieta básica. En la Costa
Atlántica (Costa Caribe) de Colombia se
ha cultivado así el fríjol zaragoza o carauta (Phaseolus lunatus L.) y ha tenido gran
aceptación solo o asociado con yuca
(Manihot esculenta), maíz (Zea mays),
guandú (Cajanus cajan), millo (Sorghum
sp) y ñame (Dioscorea alata). Este fríjol,
por su gran rusticidad, su valor proteico
y su pertenencia a la cultura local, puede
complementar la dieta de hidratos de
carbono predominante en la ‘provincia’
Zenú. Por ello, el presente trabajo se realizó, entre 1990 y 1993, para promover el
cultivo del fríjol carauta en tres comunidades del resguardo indígena de San
Andrés de Sotavento. Se consideraron
los siguientes objetivos: realizar colectas
de fríjol carauta en la Costa Atlántica colombiana, evaluar las características
agronómicas de las accesiones colectadas, y conocer el grado de aceptabilidad
y la posibilidad de reinserción de las accesiones. De las 16 accesiones evaluadas,
sólo 8 son homogéneas en cuanto a su
rendimiento, con un coeficiente de variación que oscila entre 10.3% y 28.2%. Su
contenido de ácido cianhídrico (compuestos cianógenos) oscila entre 17.6 y 96.0
ppm, que las hace aptas para el consumo
humano. Por estas características, las
ocho accesiones escogidas se consideran
promisorias para la zona del Resguardo
Indígena de San Andrés de Sotavento.
Después de 3 años de iniciado el estudio,
sólo el 20% de los productores han continuado sembrando el frijol carauta como
componente adicional de los sistemas de
producción basados en la trilogía maízyuca-millo. Esta baja reinserción se explica por la escasa demanda de carauta en
los mercados regionales y por la competencia de otras leguminosas, como Vigna
unguiculata y Vigna sesquipedalis.
Quatre espèces de Phaseolus (P. vulgaris, P.
lunatus, P. coccineus, P. acutifolius) ont nourri de nombreuses populations américaines
depuis l’arrivée de Colomb dans le Nouveau Monde; haricots et maïs étaient les
aliments de base de ces populations. Sur la
côte caraïbe (ou atlantique) de la Colombie, la variété de haricot carauta (Phaseolus
lunatus L.) a été depuis lors une composante importante du régime alimentaire
avec le manioc (Maniot esculenta), le maïs
(Zea mays), le pois cajan (Cajanus cajanus), le
sorgho (Sorghum sp.) et l’igname ailée
(Dioscorea alata). Ce type de haricot, compte
tenu de ses qualités alimentaires, de sa
valeur nutritionnelle et de son rapport avec
la culture locale, peut contribuer au régime
alimentaire à base de glucides des populations Zenú. Pour cette raison, les présents
travaux ont été lancés en 1990-1993 en vue
de promouvoir le haricot carauta dans trois
communautés de la Réserve indienne de
San Andrés de Sotavento. Les principaux
objectifs de ces travaux sont les suivants:
constituer une collection de haricots carauta pour la côte atlantique colombienne;
évaluer les caractères agronomiques des
accessions collectées; estimer le niveau
d’acceptabilité et la réintroduction potentielle des accessions de haricots. L’étude se
penche sur les résultats suivants: sur 16
accessions évaluées, 8 seulement ont affiché un comportement uniforme. Ainsi, le
coefficient de variation se situe entre 10,3 %
et 28,2 %. Par ailleurs, les accessions ont
une teneur en cyanure qui varie entre 17,6
et 96 ppm; elles peuvent donc être consommées sans danger. En raison de ces
caractéristiques, le haricot carauta est considéré comme une accession prometteuse
pour la Réserve indienne de San Andrés de
Sotavento. Après trois années d’efforts
pour le réintroduire, seuls 20% des producteurs cultivent encore le haricot carauta et
l’utilisent comme complément dans leur
système de production basé sur le maïs, le
manioc et le sorgho. On peut attribuer cette
adoption limitée à la faible demande de
haricots carauta dans le commerce local et
à la présence d’une variété de haricot compétitive sur le marché.
Four species of Phaseolus (P. vulgaris, P.
lunatus, P. coccineus, P. acutifolius) have
provided food to many American peoples since the arrival of Columbus in the
New World; beans and corn made the
basic diet of those cultures. In the Caribbean (or Atlantic) Coast of Colombia, the
Lima bean (Phaseolus lunatus L.) has been
since then an important component of
the diet together with cassava (Maniot
esculenta), corn (Zea mays), guandú (Cajanus cajanus), millo (Sorghum sp.) and
ñame (Dioscorea alata). This type of bean,
given its food quality, nutritious value
and relationship to the local culture, can
contribute to the mainly carbohydrate
diet of the Zenú culture. For that reason,
the present work was launched in 19901993 to promote the Lima bean in three
communities of the San Andrés de Sotavento Indian Reserve. The main objectives of this work are the following: to
make a Lima bean collection for the Colombian Atlantic Coast; to evaluate the
agronomic traits of the collected accessions; to estimate the acceptability level
and the potential reintroduction of the
bean accessions. The following results
are discussed in this work: out of 16 evaluated accessions only 8 had a uniform
performance. Thus, the variation coefficient lies between 10.3% and 28.2%. Besides, the accessions have a cyanide content that varies between 17.6 and 96 ppm;
therefore, they can be consumed safely.
Due to these characteristics, the Lima
beans are considered promising accessions for the Indian Reserve of San Andrés de Sotavento. After 3 years of reinsertion effort, only 20% of the producers
are still cropping the Lima bean and using it as a complement in their production system based in corn, cassava and
sorghum. The reasons for this low adoption are probably the low demand for
the Lima beans in the local market and
the presence of a competitve bean variety in the market.
Reincorporación del fríjol
carauta (Phaseolus lunatus L.)
a la agricultura tradicional en
el resguardo indígena de San
Andrés de Sotavento (Córdoba,
Colombia)
Réintroduction du haricot de
Lima (Phaseolus lunatus L.)
dans l’agriculture traditionnelle
au bénéfice des communautés
autochtones de San Andrés de
Sotavento (Córdoba, Colombie)
Reincoportating Lima bean
(Phaseolus lunatus L.) into the
traditional agriculture
protecting indigenous
communities of San Andrés de
Sotavento (Córdoba, Colombia)
Key words: Collecting, Colombia,
Lima bean, Phaseolus lunatus, reintroduction, traditional farming
24
Introducción
El fríjol lima (Phaseolus lunatus L.), denominado carauta, caraura y
zaragoza en la Costa Atlántica (Costa Caribe) de Colombia, es
una leguminosa de grano que ha estado ligada a la cultura y a
las tradiciones indígenas y mestizas de esta región de Colombia.
Este fríjol se distribuye desde la península de la Guajira hasta el
Golfo de Darién, en los límites con Panamá. Sin embargo, a
excepción de algunas zonas de sabana de Sucre y del Bajo
Magdalena, su producción y su consumo son marginales y no se
vende en los mercados regionales.
En el Resguardo Indígena de San Andrés de Sotavento,
perteneciente a la etnia Zenú, existe la memoria histórica del
cultivo de carauta y se han mantenido algunas tradiciones
agrícolas alrededor de la asociación del maíz, la yuca y el ñame.
Se consideró, por tanto, pertinente iniciar en la zona un
programa de fomento del cultivo y hacer allí una evaluación de
la aceptación del fríjol entre las comunidades indígenas.
Preferencias regionales
El género Phaseolus ha sido un importante recurso agrícola en
América y en el viejo mundo, donde se ha consumido como
semilla seca, como vaina verde o como un producto procesado.
Es una importante fuente de proteína y de calorías para la dieta
humana en Africa y en América, donde es un suplemento de la
dieta calórica basada en maíz, yuca, ñame y arroz (Oriza sativa). El
incremento del costo de la proteína animal en Europa y América
del Norte ha convertido algunas especies de fríjol en fuente
importante de proteína. Cada país y cada zona geográfica tiene
una preferencia respecto al color y al tamaño de la semilla de
fríjol, la cual proviene de la dispersión (y el consiguiente
consumo) de ciertos tipos de fríjol en el pasado.
En la Costa Atlántica colombiana, las leguminosas
preferidas son el fríjol criollo (Vigna unguiculata), en las variedades
de semilla blanca y roja, que se consume abundantemente durante la semana santa; la habichuela (Vigna sesquipedalis) cuyas
vainas y semillas se consumen tiernas; el guandú (Cajanus cajan);
y la carauta (Phaseolus lunatus).
El nombre carauta se deriva, posiblemente, de los carautas,
una tribu caribe que se asentó entre los ríos Sinú y León, cerca de
la frontera colombo-panameña. La carauta tiene demanda en
los mercados de Barranquilla como semilla tierna, tipo sieva de
color blanco, que se produce en las riberas del Bajo Magdalena.
Asimismo, se expende en los mercados de las sabanas de Sucre
(Sincelejo, Corozal, Ovejas, Chalán y Colosó) y de Bolívar (El
Carmen, San Juan y San Jacinto), como semilla seca y tierna,
tipo sieva y papa, de color rojo con vetas negras y blanco con
vetas rojas.
En esas sabanas se siembran accesiones volubles y arbustivas
alrededor de los cultivos de yuca, maíz, millo y ñame; la carauta
es un componente importante de la dieta rural pues todas las
tardes se consume este fríjol con arroz.
Diferentes análisis indican que el fríjol carauta tiene 20% de
proteína que, aunque de buen valor biológico, alto contenido de
lisina y gran digestibilidad, es deficiente en treonina. Este fríjol
posee un glucósido cianogénico, la faseolunatina, y la enzima
linamarasa, los cuales se hidrolizan en presencia de humedad
en la molienda y liberan glucósidos generando ácido cianhídrico
(HCN), cuyo contenido varía de 10 a más 300 mg/100g de fríjol.
Se acepta con frecuencia que las semillas coloreadas de fríjol
lima tienen un alto contenido de glucósidos, aunque algunos
estudios reportan ausencia de correlación entre ambos
caracteres. Muchos genotipos comerciales tienen sólo de 1 a 8
ppm de HCN en la semilla, en la que generalmente se acepta una
concentración límite de 100 a 200 ppm de HCN.
Metodología
Las colectas se hicieron en la Costa Atlántica colombiana y se
dedicaron a las variedades criollas de fríjol carauta cultivadas
por los pequeños agricultores de la región. Durante la etapa de
exploración, en los sitios de colecta se tomaron datos según el
formulario de recolección de fríjol del Instituto Internacional de
Recursos Fitogenéticos (IPGRI) y del Centro Internacional de
Agricultura Tropical (CIAT). Asimismo, mediante entrevistas y
encuestas con los productores se amplió la información sobre la
etnobotánica de la especie.
Los materiales recolectados fueron enviados al CIAT con el
fin de ampliar la colección mundial de germoplasma de fríjol
lima; gran parte de estas accesiones ya hacen parte de los
catálogos de ese Centro.
La semilla colectada era insuficiente para establecer las
accesiones entre las comunidades indígenas del resguardo de
San Andrés de Sotavento, en Córdoba; se montó, por tanto, un
ensayo de multiplicación de semillas durante 1988B, en los
predios de la Universidad de Córdoba, en las condiciones
siguientes: temperatura promedio de 29 ºC, humedad relativa
del 85%, precipitación anual de 1200 mm, suelos francos y
altura de 19 m.s.n.m.
Las plantas del ensayo se sembraron a 1 m entre una y otra
y se montó un sistema de espalderas de alambre sostenidas por
postes de madera. Las plantas manifestaron un gran desarrollo
vegetativo debido a la intensa precipitación que cayó durante el
tiempo de cultivo.
Los problemas de sanidad del ensayo fueron los crisomélidos
(Diabrotica sp., Omopoita sp., Cistena sp., Diphaulaca sp., Ginandrobrotica
sp.), las chinches de encaje(Gargaphia sp.) y el virus del mosaico
(VMB). Se manifestó asimismo un gran porcentaje de variación
en la descendencia de algunos genotipos debido a la alogamia
ocurrida entre estos materiales de fríjol.
Partiendo de estos datos, se montó otro ensayo en 1990 en la
finca Mina de Oro, localidad de Comején, en Purísima, Córdoba,
perteneciente al Resguardo Indígena de San Andrés de
Sotavento, en las condiciones siguientes: suelos ácidos de textura
arenosa, terreno de topografía ondulada, temperatura promedio
de 29ºC, humedad relativa de 85%, precipitación anual de 1200
mm y una altitud de 20 m.s.n.m.
El suelo se preparó según la tecnología tradicional de la
zona: pica, quema y limpia. La siembra manual se hizo
colocando tres semillas por sitio y raleando a los 15 días para
dejar sólo una planta, a un metro entre plantas y a un metro
entre surcos. El ensayo se hizo en parcelas de 54 m 2,
organizadas en un diseño de bloques al azar. Había 10
plantas por parcela y se tomaron datos de fenología, de
componentes del rendimiento, de área foliar en la antesis y del
índice de área foliar.
Asimismo, en el laboratorio de utilización de yuca del
CIAT se determinó el contenido de HCN de la semilla por el
método de Cooke.
Los granos cocidos y aliñados (de igual forma en cada caso)
fueron presentados a un panel compuesto por 50 indígenas de
la comunidad de Comején para evaluar la aceptabilidad de los
materiales. A las variables de medición y de recuento se les
aplicó un análisis de estimación de intervalos.
En 1991 se repartió, en la localidad de Comején, semilla
mezclada de carauta entre 42 familias, con la recomendación de
que la sembraran en sus parcelas. En 1992 se repartió de nuevo
semilla de una de las muestras promisorias (Unicor 3) entre las
mujeres de la comunidad para que la sembraran en los patios.
En 1993B se hizo un recorrido para evaluar la presencia de
este fríjol en los campos de los agricultores de Comején. Se
evaluaron además las condiciones de sanidad del cultivo y el
manejo de éste en las parcelas y en los patios. Finalmente, se
hizo una encuesta a las mujeres de esta comunidad.
Resultados
Etnobotánica del cultivo
El fríjol carauta se encuentra distribuido en toda la Costa
Atlántica (Costa Caribe) de Colombia, especialmente en los
departamentos de Atlántico (Juan de Acosta, Tubará, Usiacurí
y Ponedera), Bolívar (El Carmen, La Casona, San Jacinto y San
Juan), Sucre (Ovejas, Colosó, Chalán y Don Gabriel),
Magdalena (Sevilla, Guaimaro, Guacamayal y Sierra Nevada),
Córdoba (Montería, Tierralta y Valencia), y en el Urabá
Antioqueño.
La denominación más usual es carauta, aunque en algunos
sitios se conoce como haba, zaragoza, garbanzo o con nombres
que reflejan la forma y el color de la semilla, como panchita, fríjol
rojo, carita de santo, huevo de codorniz y venezolana.
En los sitios de colecta se desconoce su procedencia; los
campesinos lo consideran nativo porque se ha cultivado de
generación en generación.
En 50% de los casos, aproximadamente, los cultivos son de
patio y consisten en unas 10 plantas alrededor de la vivienda.
Sólo en los departamentos de Atlántico y Sucre lo cultivan en
campo abierto pero no llega a 0.5 ha el área sembrada por familia
(500 a 1500 plantas). A excepción del área tabacalera de Sucre,
en ninguna zona se mecaniza la tierra sino que usan el
procedimiento tradicional de roza, tumba y quema. Se utilizan
las cercas o ramas de árboles como tutores (en Sucre), se intercala
con la yuca o el maíz (en Magdalena) o se asocia con yuca y
millo (en Atlántico).
En la siembra no se aplica ningún producto que proteja la
semilla. Por lo regular, se siembra a distancias de 3 m entre
plantas, cuando se hace en el patio; en el campo, a de 2 m entre
plantas y a 2 ó 3 m entre surcos. Para sembrar utilizan espeques
de madera, colocando 3 a 4 semillas por sitio. En ninguna de las
zonas del ensayo se fertiliza y en todas se hace control manual
de las malezas.
Las siembras se hacen a principios de la época de lluvias
(abril-mayo) o a principios del estiaje en los terrenos aluviales de
las riberas del río Magdalena.
Son comunes los ataques de crisomélidos (Cerotoma sp.,
Diabrotica sp., Diphaulaca sp., Colapsis sp., Cistena sp.). En Córdoba
y Magdalena se ha encontrado en las semillas el coleóptero
perforador de la semilla (Hipotenemus sp.), el cual se introduce por
el hilum y hace galerías dentro de la semilla; se han contado
hasta 24 insectos por semilla y las accesiones más atacadas son
Unico 3 y Unico 7. Se encontraron además plantas con fuertes
ataques de la chinche de encaje (Gargaphia zanchesi). En las riberas
del Magdalena es común el virus del mosaico (VMB).
La producción de grano se inicia 3 meses después de la
siembra; el fríjol se consume como semilla tierna y como semilla
seca. En las zonas rurales de los municipios de Ovejas, Colosó y
Chalán, la comida tradicional de la tarde es arroz con carauta,
en proporción de 1 libra de carauta por 1 libra de arroz. La
carauta seca se pone a ablandar en agua y así se elimina un poco
el cianuro.
No hay todavía un cálculo preciso del rendimiento de este
fríjol pues la cosecha es escalonada y no se llevan estadísticas.
En la mayoría de los casos, la producción es para autoconsumo
aunque en las ciudades donde hay demanda (Barraquilla,
Ovejas, El Carmen) se colocan excedentes en el mercado que
llegan a tener altos precios (Col$800/lb).
El fríjol almacenado es atacado con frecuencia por el gorgojo
pintado (Zabrotes subfasciatus). Según los campesinos encuestados,
el fríjol carauta necesita menos tiempo para la cocción que los
fríjoles andinos (Phaseolus vulgaris); además, no produce malestar
estomacal y necesita pocos cuidados en el campo debido a su
rusticidad.
Evaluacion de los materiales colectados
Los materiales colectados aparecen en el Cuadro 1. Se les asignó
un código compuesto por las siglas Unicor, que corresponde al
lugar del primer depósito, o sea, la Universidad de Córdoba, y
un número según el orden en que fueron colectados. El CIAT les
asignó un código, compuesto por una letra y un número que
corresponde a los 3 tipos: sieva, papa y lima grande. Predomina
en los materiales el tipo sieva y son de hábito indeterminado
trepador.
Las plántulas tienen hipocotilos verdes o verdes con
pigmentos púrpura y los tallos variaron del verde al púrpura. En
el haz de las hojas primarias se presentaron, en algunos
genotipos, manchas plateadas a lo largo de las nervaduras.
Las hojas son pubescentes, con el folíolo terminal de forma
lanceolada, ovado-lanceolada o redonda. Las flores son de color
blanco o lila con las alas cerradas o superpuestas, en la mayoría
de los casos. Sólo la Unicor 6, que tiene apariencia de fríjol lima
grande, tenía las alas abiertas.
Las etapas vegetativas (V0, V 1, V 2 y V3) fueron uniformes en
los materiales; la etapa V4, sin embargo duró 34 días en las
accesiones Unicor 2, 8 y 10 y 75 días en la Unicor 16. Las etapas
reproductivas, mostraron un comportamiento diferencial en todos
los materiales: la etapa R5 tuvo de 7 a 22 días de duración, la R6
osciló entre 5 y 9 días, la R7 de 6 a 20 días y la R8 de 14 a 22 días.
En cuanto al rendimiento, los materiales más rendidores son
Unicor 6, Unicor 4 y Unicor 7, con 1254.0, 879.1 y 704.0 kg/ha,
respectivamente. Los mayores niveles de área foliar en la antesis
se registraron en la accesión Unicor 2 (6726 cm2/planta); en la
Unicor 10 ese valor fue de 2746 cm2/planta.
26
Cuadro 1. Colección regional del fríjol carauta en la Costa Caribe de Colombia
Nombre
local
Sitio de
origen
Carauta
Haba
Fríjol rojo
Zaragoza
Zaragoza Roja
Carauta
Carauta
Carauta
Carauta
Carauta
Carauta
Carauta
Carauta
Carauta Ponchita
Carita de Santo.
Valencia (Córdoba)
Santafé de (Antioquía)
Loma Grande (Urabá)
J.de Acosta (Atlántico)
Tubará (Atlántico)
Cansona (Bolívar)
Ayapel (Córdoba)
Sampués (Sucre)
Chalán (Sucre)
Colosó (Sucre)
Tuchín (Córdoba.)
Tierralta (Córdoba)
Ponedera (Atlántico)
Usiacurí (Atlántico)
†
Altura
(m s.n.m.)
Latitud
Longitud
Código
Unicor
Código
CIAT
55
28
100
720
25
43
150
8°15’N
6°10’N
8°5’N
10°50’N
10°40’N
9°35’N
8°18’N
9°10’N
9°35’N
76°0’W
7530W
7620W
75°03W
75°20’W
7510W
7509W
7520W
7525W
G26322
G26313
G16312
G26316
G26314
G26320
G26317
G26324
150
50
77
8
100
9°20’
9131
8°12’
1038N
1045N
7515
7530W
76°5’W
7446W
7459W
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
Unicor
58
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
†
G26323
†
G26321
G26319
G26325
G26315
No fueron donados.
Contenido de ácido cianhídrico (HCN)
El alto contenido de compuestos cianogénicos (ácido
cianhídrico) es una característica indeseable en algunas
accesiones de fríjol carauta, pues le da un sabor amargo a las
semillas. En el Cuadro 2 se observa que los contenidos de HCN
oscilan entre 17.6 ppm, en la accesión Unicor 1, y 212 ppm en
Unicor 6; esta última es el material que supera en este rubro los
límites permitidos por la Organización Mundial de la Salud.
Efectos de la reincorporación
El 60% de los productores de grano que recibieron, en 1990, semilla
mezclada no sembraron carauta alegando que las semillas se habían
dañado por ataques de insectos. Por tanto, 40% sembraron el
primer año, aunque sólo la mitad de ellos (20%) han conservado la
semilla. La mayoría de sembró este fríjol en los patios, cerca de las
casas, y utilizaron como tutores las cercas y las ramas de los árboles.
Al juzgar la aceptabilidad del fríjol como alimento, todos
manifestaron que les gusta la carauta (P. lunatus), la habichuela (Vigna
sesquipedalis) y el fríjol criollo(Vigna unguiculata).
Cuadro 2. Contenido de cianógenos (HCN) en las
semillas secas del fríjol carauta
Accesión
HCN (ppm)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17.6
21.6
20.3
60.0
43.0
212.0
24.0
51.0
38.0
39.3
25.0
96.0
36.3
34.0
35.6
27.3
Según la encuesta aplicada a las mujeres que recibieron
semilla de Unicor 3 a principios de 1993, a todas les gusta
carauta y un 50% de ellas la sembraron el primer año.
En cuanto al consumo, el 70% las prefieren tiernas (verdes) y
un 30% como semilla seca. Preparan el fríjol como sopa, mote,
con arroz y con guisos. Al momento de la evaluación del estado
de las plantas (agosto de 1993), éstas se hallaban en su período
reproductivo, en condiciones sanitarias aceptables aunque
presentaban ataques de crisomélidos y del virus del mosaico.
En una evaluación de campo que incluía los patios de las
casas, en octubre de 1993, los componentes principales del
sistema eran maíz, ajonjolí, yuca, fríjol criollo y algunas
hortalizas como col y berenjena (Cuadro 3).
La situación de Comején es similar a la de otra comunidad
indígena (Bajo Grande) donde se repitió el programa. Los
resultados indicaron que los componentes principales del
sistema de producción son la yuca, el maíz y el ajonjolí; siguen
en importancia el fríjol criollo, la habichuela y las hortalizas,
mientras que el fríjol carauta es un componente marginal. Por
razones económicas y culturales, el maíz y la yuca son la base de
la alimentación de estas comunidades; se explica en parte la
presencia del ajonjolí (Sesamun indicum) por la demanda y buenos
precios que tiene en los mercados regionales, así como por su
tolerancia a las sequías de fin de año. Algo similar ocurre con el
fríjol criollo (Vigna unguiculata) que, además de su precocidad (60
días hasta la cosecha), no requiere de tutores.
La habichuela (Vigna sesquipedalis) tiene una producción alta,
se consume como fruto tierno y tiene demanda en los mercados
regionales. La carauta, a pesar de ser conocida y aceptada, no se
ha convertido en un componente significativo en los sistemas
tradicionales de producción y de consumo de estas comunidades
por las siguientes razones: hay otras leguminosas competitivas
de mayor demanda regional, el fríjol carauta requiere de tutores,
tiene un período vegetativo largo y no tiene demanda en los
mercados locales. Esta especie entra en el conocido círculo
vicioso de que una vez que un cultivo ha sido abandonado, la
escasa producción y el consumo marginal subsecuente dificultan
su reinserción en los sistemas tradicionales de producción.
Conclusiones
• En muchas zonas campesinas de la Costa Caribe de Colombia se mantiene, como cultivo marginal, el fríjol carauta o
zaragoza; sin embargo, su proyección hacia los mercados de las
grandes ciudades de la región es escasa.
• Hay una gran variedad de germoplasma de este fríjol y en él
predominan los tipos sieva. El contenido de compuestos
generadores de HCN en los materiales colectados, excepto en el
genotipo Unicor 6 (626320), no sobrepasan el nivel de 100 ppm
considerado tóxico para consumo humano. Por consiguiente,
no es el contenido de HCN de las semillas el factor que ha
influido en la posición marginal que ocupa hoy el cultivo.
• En un experimento realizado en la vereda Comején del
Resguardo Indígena de San Andrés, Córdoba, Colombia, en
donde se repartió semilla y se hizo una campaña de fomento del
cultivo entre hombres y mujeres, sólo el 20% de los productores
continúa sembrando esta especie, después de 3 años de iniciada
la campaña.
• El bajo nivel de reinserción de este cultivo en la agricultura
tradicional se debe a la escasa demanda de la carauta en los
mercados de la zona y a la existencia de otras leguminosas
competitivas (Vigna sp).
Referencias
Ballesteros, P.G. 1990. Evolución del fríjol lima (P. lunatus).
Curso de evolución orgánica. Colegio de Posgraduados,
Montecillos, Estado de México. 89 p.
Barrera, M., G. Ballesteros y A. Torres. 1992. Caracterización
agromorfológica de 12 accesiones de fríjol carauta (Phaseolus
lunatus L.) en el valle del Sinú Medio. Tesis. Universidad de
Córdoba. Montería, Colombia.
Cooke, R.D. 1979. Enzymatic assay for determining the cyanide
content of cassava and products. Cassava Information Center, Centro Internacional de Agricultura Tropical (CIAT),
Cali, Colombia.
Debouck, D. 1979. Proyecto de recolección de germoplasma de
Phaseolus en México CIAT/INIA. Centro Internacional de
Agricultura Tropical (CIAT), Cali, Colombia.
Fernández, F., P. Gepts y M. López. 1985. Etapas del desarrollo
de la planta de fríjol. En: Fríjol: Investigación y producción.
Progrma de las Naciones Unidas para el Desarrollo (PNUD)
y CIAT, Cali, Colombia. p. 61-78.
Lyman, J.M. 1980. Adaptation and breeding studies on the lima
bean (Phaseolus lunatus L.) as a food legume for Latin
America. Tesis (Ph.D.). Cornell University, Ithaca, NY, E. U.
275 p.
Maquet, A. 1989. Bean Program. En: CIAT Annual Report. CIAT,
Cali, Colombia. (Multicopiado.)
28
ARTICLE
Plant Genetic Resources Newsletter, 2000, No. 123: 28 - 34
El conocimiento local y su contribución al trabajo
de rescate, conservación y uso de las semillas de
Phaseolus y Vigna en las vegas del Río Orinoco,
Estado Guárico, Venezuela
Angela Bolívar*, Marisol López, María D’Goveia y Margaret Gutiérrez
Fondo Nacional de Investigaciones Agropecuarias-Centro Nacional de Investigaciones Agropecuarias, Apdo. Postal
4653, Maracay 2001, Venezuela. Email: [email protected]; [email protected]; [email protected]
Resumen
El conocimiento local y su
contribución al trabajo de
rescate, conservación y uso de
las semillas de Phaseolus y
Vigna en las vegas del Río
Orinoco, Estado Guárico,
Venezuela
Con el propósito de colectar y conservar
ex situ materiales de Phaseolus y Vigna, y
también de caracterizarlos y aprender
del conocimiento agrícola local de los
productores, se utilizó el método de investigación de la entrevista etnográfica,
diseñada para comprender los eventos
observados haciendo énfasis en el análisis cualitativo etnográfico. Se tomaron
datos a partir de una muestra de informantes clave (32 productores) localizados en las vegas de Parmana y Cabruta,
extremo sur del Estado Guárico, en la
margen izquierda del río Orinoco, en
Venezuela. De la colecta se obtuvieron
21 materiales locales cuyos pasaportes
fueron descritos partiendo de la categorización y del análisis de la entrevista
etnográfica. Los resultados indican que
los diversos materiales colectados provienen de un mejoramiento artesanal centrado en el conocimiento local de los productores de las vegas visitadas, los cuales,
a través de sus experiencias y saberes,
han contribuido a la conservación y uso
de estos granos. Por otra parte, las condiciones de mediana a alta fertilidad de los
suelos de las vegas bajo estudio, vistas a
través de los análisis de suelos, es al parecer una de las causas de la permanencia
en el tiempo de estos sistemas de producción de bajos insumos, adaptados al
ambiente local y a la conservación del
mismo. Los materiales colectados son,
además, fuente primaria de recursos alimenticios para el mantenimiento del núcleo familiar y reducen además el área
per cápita necesaria para la subsistencia;
esta área está determinado por las inundaciones anuales del río Orinoco. Confieren también estos mataeriales características socioculturales muy particulares que deben considerarse a fin de
mejorar la calidad de vida del productor
y su familia.
Résumé
Les connaissances locales et
leur contribution à la
sauvegarde, à la conservation
et à l’utilisation des semences
de Phaseolus et de Vigna au
Venezuela
L’étude s’est appuyée sur des entretiens
ethnographiques en vue de collecter et
de conserver ex situ du matériel génétique de Phaseolus et de Vigna et de mieux
connaître les pratiques agricoles locales.
Les données ont été recueillies à partir
d’un échantillon de 32 informateurs,
situés dans les plaines de Parmana et de
Cabruta et dans l’Etat de Guárico, sur la
rive gauche de l’Orénoque, au Venezuela. Vingt et un échantillons provenant de
cette collecte possèdent des données
passeport basées sur la catégorisation et
l’analyse
des
entretiens
ethnographiques. Les résultats indiquent
que les différents échantillons collectés
sont le fruit de l’amélioration traditionnelle des cultures fondée sur la connaissance locale des plaines visitées. Les agriculteurs ont contribué par leurs connaissances à la conservation et à l’utilisation
de ces légumineuses à graines. L’analyse
des sols fait apparaître une fertilité moyenne à élevée, qui semble être l’une des
raisons du maintien dans le temps de ces
systèmes de production à faible apport
d’intrants, adaptés à l’environnement local et à sa conservation. Le matériel collecté joue également un rôle fondamental dans l’alimentation des familles et réduit la superficie consacrée aux cultures
de subsistance: cette zone est souvent
déterminée par la crue annuelle de
l’Orénoque. Ce matériel génétique possède des caractéristiques socioculturelles
particulières qui devraient être prises en
compte afin d’améliorer le bien-être des
agriculteurs et de leurs familles.
Summary
The local knowledge and it
contribution in the rescue,
conservation and use of
Phaseolus and Vigna seeds in
margin areas of the Orinoco
River, Cabruta, Parmana
Guárico - Venezuela.
The study used ethnographic interviews
in order to collect and conserve ex situ
Phaseolus and Vigna germplasm and to
gain better knowledge of local agricultural practices. Data were collected from
a sample of 32 key informants, located in
the plains of Parmana and Cabruta and
the extreme Guárico state, on the left
margin of the Orinoco river, Venezuela.
Twenty-one materials of this collection
have passport data described based on
the categorization and analysis of the
ethnographic interviews. The results indicate that diverse materials collected are
the result of traditional crop improvement based on local knowledge of the
plains visited. Farmers have contributed
through their local knowledge to the
conservation and use of these grain legumes. The medium to high soil fertility
as determined by soil analysis appears to
be one of the reasons for the maintenance over time of these low-input production systems that are adapted to the
local environment and its conservation.
In addition, the collected materials are a
primary source of food in the family diet
and reduce the land area needed for subsistence: this area is often determined by
the annual flooding of the Orinoco. This
germplasm has particular sociocultural
characteristics which should be taken into
account in order to improve the welfare
of farmers and their households.
Keywords: Collecting, ethnographic
interviews, germplasm, germplasm
conservation, local knowledge
Introducción
El conocimiento agrícola local es el que generan los agricultores,
hombres y mujeres, a lo largo del tiempo; contiene información
acerca de las preferencias y prácticas de los cultivos y se transmite
de generación en generación mediante tradición oral. Este
conocimiento representa una reserva importante de experiencias
y saberes para la toma de decisiones ante los distintos problemas
y retos que enfrenta una comunidad (Quiroz 1996).
Sobre el conocimiento agrícola local se han realizados
interesantes estudios, entre los cuales están los de Bentley (1989),
Maundu (1990), Cruz (1990) y Mathias (1996); estos
investigadores dejan ver en ellos la posibilidad de conservar los
recursos fitogenéticos y mejorar la producción agrícola de una
comunidad si se cruza la matriz de conocimiento local de los
agricultores con el conocimiento agrícola de los investigadores;
ambos se ayudarían y complementarían en la búsqueda de
soluciones, tanto técnicas como de conservación de los recursos
fitogenéticos. Uno de los principales insumos que se considera
actualmente en los Centros de Investigación Agrícola es el
conocimiento local; han adquirido experiencia en este campo el
ICRISAT, el CIAT y el FONAIAP Lara y ya han incluido
agricultores en sus programas de investigaciones.
En Venezuela, las leguminosas comestibles son un
componente básico en la dieta del productor y de su familia; por
ello, considerar el conocimiento local de los agricultores, hombres
y mujeres, sobre la producción, conservación y uso de las
leguminosas es una estrategia clave que facilita el rescate de
variedades locales y de materiales nativos; unas y otros podrán
incorporarse luego en programas de mejoramiento genético por
las vías de la conservación in situ y ex situ. En este trabajo se
contempla la conservación ex situ; por tanto, las semillas
colectadas en este estudio se mantendrán fuera de su hábitat
original, en las instalaciones de los bancos de germoplasma para
semillas del CENIAP (Centro Nacional de Investigación
Agropecuaria) perteneciente al FONAIAP (Fondo Nacional de
Investigaciones Agropecuarias de Venezuela).
Al considerar la importancia que tiene el conocimiento
agrícola local para colectar y conservar materiales, surgen
limitaciones de índole metodológico cuando se trata de
abordarlo. Para realizar este trabajo, se aplicaron los métodos
cualitativos etnográficos propuesto por Martínez (1990).
Para entender mejor el significado de la investigación
etnográfica, consideremos algunas definiciones:
• La etnografía, según Erikson (1973), es el estudio detallado
de una sociedad o unidad social en particular; para Woods
(1985), este término deriva de la antropología y significa la
descripción del modo de vida de una raza o grupo de
individuos; Martínez (1996) señala que el término etnográfico
significa la descripción (‘graphos´) del estilo de vida de un
grupo de personas habituados a vivir juntos (‘ethnos´) e indica
que los estudios etnográficos, por sus características técnicas
basadas en la observación, reciben otros nombres entre los
cuales están los siguientes: método observacional participante,
estudio de caso, método interaccionista simbólico, método
fenomenológico, interpretativo o constructivista; sin embargo,
la denominación más generalizada es la de métodos
cualitativos.
• Para Bogdan y Biklen (1982) la frase ‘metodología
cualitativa´ se refiere, en su más amplio sentido, a la
investigación que produce datos descriptivos, hablados o escritos
y a la conducta observable. Dadas estas premisas, establecemos
los objetivos del trabajo :
- por una parte, colectar semillas de Phaseolus y Vigna y
entregarlas al banco de germoplasma de FONAIAP para su
caracterización científica, su evaluación, conservación y uso en
programas de mejoramiento genético;
- por otra parte, aprender del conocimiento local de los
productores de las zonas sobre la conservación, producción y
uso de las semillas de Phaseolus y Vigna para caracterizarlas.
Antecedentes
Características agroecológicas de las vegas del
Río Orinoco
El estudio realizado por Riera y Guerrero (1984) señala las
siguientes características agroecológicas de las vegas del Río
Orinoco. Tienen una superficie de 75,153 ha en la zona
estudiada; representan el 2.1% de la superficie total de la Región
Nororiental del Estado Guárico. Los suelos están dentro de la
unidad agroecológica E-172. Fisiográficamente, la unidad se
define como planicie de desborde del Río Orinoco.
La precipitación promedio anual es de 1400 mm, que se
concentra en seis meses en los que ocurre el 91% de la
precipitación total anual; los picos están en julio y agosto. Los
suelos predominantes son de los órdenes Aquepts y Fluvents, y
las texturas más comunes son francolimosas (FL) y francoarcillolimosas (FAL). La fertilidad es considerada de media a
alta; los niveles de disponibilidad de nutrimentos (en ppm) son
de 15 a 20 para el fósforo, de 90 a 280 para el potasio y de 280 a
300 para el calcio.
Estas características edafoclimáticas, entre otras, son las que
antropólogos como Sanoja y Vargas (1978), consideran
fundamentales para que los primeros grupos humanos
asentados en la región (de 600 a 1000 años A.C.) lograran un
alto grado de integración social y de cohesión cultural basadas
en la agricultura, la pesca fluvial y la caza terrestre. Estos grupos
debieron ser suficientes para establecer en la zona una población
de cierta densidad que ha perdurado más de 2600 años, según
los mismos autores.
Materiales y métodos
La metodología utilizada para desarrollar esta investigación se
basa en la propuesta de Martínez (1990) sobre investigación
cualitativa etnográfica, que consiste en la producción de estudios
analítico-descriptivos de las costumbres, creencias, prácticas
sociales, conocimientos y comportamiento de una cultura en
particular. En estos estudios prevalece la observación
participante, se centra la atención en el ambiente natural, se
incorpora como co-investigadores a algunos sujetos escogidos y
se evita la manipulación de variables por parte del investigador.
Este trabajo contiene, como resultado, la categorización de los
datos descriptivos hablados y la conducta observable del
productor obtenida de una muestra intencional de informantes
clave (32 productores) durante el período de preparación del
terreno, de siembra y de cosecha en los meses de mayo, de
30
octubre a noviembre de 1999 y de febrero del 2000. La
metodología contempla los siguientes pasos:
Delimitación de las zonas de colecta
La zona delimitada correspondería a un caserío, un pueblo, el
Estado o el país. La zona de colecta para este trabajo está en el
eje Parmana-Cabruta localizado en el extremo sur del Estado
Guárico, en la margen izquierda del río Orinoco, en Venezuela,
entre las latitudes 7º 30’ y 8º30’ Norte y las longitudes 65º 30’ y
66º 30’ Oeste. Su superficie es de 75,153 ha pertenecientes a una
misma unidad agroecológica. Entre las características físicas
naturales más importante de la zona están las crecientes anuales
del río Orinoco que regeneran periódicamente la capa vegetal de
las riberas y de las islas del río.
Uso actual. Estos suelos se usan en ganadería extensiva
trashumante y para agricultura en las vegas del río; los principales
cultivos son: caraota, frijol, algodón y patilla, que dan una cosecha
al año a causa de la inundación a que están sometidos los suelos.
Ubicación geográfica. Figuras 1 indica la ubicación de la
zona estudiada.
Fig.1. Atardecer en Las Vegas del Río Orinoco. ParmanaCabruta, Venezuela.
Epoca del estudio
Se eligieron los meses del año que, según los factores climáticos,
garantizan la presencia de los elementos de estudio de las
plantas (flor, fruto o semilla).
Se realizaron 11 visitas en tres épocas distintas :
a) 3 días en época de sequía (colecta de semilla), en el mes de
mayo de 1999;
b) 3 días en época de salida de lluvias (preparación del terreno
y siembra), en el mes de octubre de 1999;
c) 3 días en época de sequía (mantenimiento del cultivo), en el
mes de noviembre de 1999;
d) 2 días en época de sequía (cosecha ), en el mes de febrero del
2000.
Permisología. Se pidió autorización para colectar muestras
con fines científicos a:
- Autoridades (cartas, entrevista)
- Comunidades (cartas, reunión, taller)
Instrumentos para recolectar información
Para realizar este trabajo se escogieron estrategias de recolección
de datos etnográficos, en especial, técnicas de triangulación de
información. Estas permiten efectuar validaciones de
información cruzada, recogiendo datos de diferentes fuentes
(Patton 1987). En el presente caso, se emplearon en esta técnica
tres instrumentos: la entrevista, la convivencia y la observación
participante.
Entrevista. Mediante la entrevista se motivó al productor,
ayudándole a explorar, reconocer y aceptar sus propias vivencias.
Se utilizó una guía que seguía temas elegidos previamente
(aspectos sociales, tecnológicos y referentes a los materiales).
En cuanto a los aspectos sociales, se recopiló información sobre
el núcleo familiar: número de personas que laboran en la unidad
de producción; organización del trabajo (familiar, asalariada
fija, estacional); participación de la mujer en el trabajo
productivo, reproductivo y comunitario; fuentes de
conocimientos (escolaridad, textos, tradición oral, visitas
técnicas); principales fuentes de ingreso; autoconsumo y
relaciones con el mercado local.
En relación con los aspectos tecnológicos, se abordaron tres
etapas: preparación del terreno y siembra, mantenimiento del
cultivo y cosecha. En relación con los materiales se trataron los
temas siguientes: formas de conservación, selección de la
semilla, usos, origen del material, nombre común, peso de la
semilla, forma y color de la semilla).
La entrevista se complementa con notas de campo de tipo
memorando, grabaciones o filmaciones; en nuestro caso sólo se
usaron las notas.
Codificación. Cada entrevista se desarrolló en forma de
relatos o historias, las cuales se codificaron con un número línea
por línea; estas historias se leen todas las veces que sea necesario
para luego seleccionar categorías comunes.
Categorización e interpretación. Se dividieron los contenidos
de la entrevista en temas similares y se agruparon según las
características comunes, lo cual permitió seleccionar las
siguientes categorías descriptivas:
- selección y conservación de semillas,
- formas de consumo,
- origen de la semilla,
- preparación y adecuación del suelo para la siembra, y
- mantenimiento del cultivo.
Convivencia. La convivencia es una técnica sencilla que nos
permite interactuar con la comunidad. El objetivo primordial de
esta técnica es lograr la empatía entre los investigadores y los
productores. La convivencia con fines de investigación en
recursos fitogenéticos logra que, en el plano cognoscitivo, la
persona empática tome la perspectiva de la otra persona y se
esfuerce, al hacerlo, por ver el mundo desde el punto de vista de
esa persona. En el plano comunicativo, el individuo empático
muestra comprensión e interés mediante claves verbales y no
verbales. La convivencia se puede desarrollar mediante alguna
actividad importante para la comunidad, bien sea a fiesta del
santo de la localidad, las ferias o las faenas de trabajo. En este
estudio se hizo en las faenas de trabajo (siembra y cosecha) y se
acopió la información mientras se aprendía haciendo,
observando y escuchando con mucha atención.
En las convivencias se obtuvo la siguientes información:
- lenguaje y tecnología local;
- el papel de la mujer,
- formas de comunicación;
- identificación de líderes ocultos o ya establecidos;
- costumbres y creencias.
Muestreo de suelos
Con el propósito de precisar más el contexto agroecológico de las
zonas de colecta, se hizo un recorrido por las áreas de estudio y
su entorno. De este modo se logró obtener visualmente una
apreciación de las condiciones descritas por Riera y Guerrero
(1984) para estas unidades agroecológicas. Durante el recorrido
se tomaron muestras de suelo con el fin de analizar la fertilidad
de éste en cada una de las unidades de producción consideradas
en la colecta. A fin de disminuir la variabilidad del suelo y
obtener muestras representativas, se definieron unidades de
muestreo (Ovalles 1992); cada unidad está representada por ½
ha o por 1 ha, considerando el tipo de manejo del suelo y sus
características comunes, o sea, tipo de vegetación, color, posición
fisiográfica y textura. En cada hectárea se tomaron de 20 a 30
muestras compuestas según la heterogeneidad del lote. Cada
muestra compuesta consta de la mezcla de submuestras (entre
10 y 15). Las muestras se toman al azar siguiendo una trayectoria
en zig-zag (Chririnos y Brito 1985).
Las submuestras se mezclaron y de la mezcla se tomó,
aproximadamente, 1 kg de suelo, el cual conformó la muestra
compuesta que fue sometida a determinaciones físicas y
químicas para conocer su fertilidad. Los resultados se
interpretaron considerando criterios de deficiencia, suficiencia y
exceso de nutrientes.
Resultados y discusión
Aplicabilidad de la metodología
Cuando visitamos una comunidad rural con fines de
investigación, observamos que posee un cúmulo de experiencias
y agudos conocimientos sobre la utilización de diversos
materiales de origen vegetal y animal, lo que les ha permitido
sobrevivir en el tiempo. En estas comunidades hay valores,
creencias y costumbres que permiten a sus habitantes, a pesar
de las condiciones adversas del clima, de la infraestructura y de
otras limitantes, resistir y permanecer en su lugar de origen.
Otras comunidades rurales, por el contrario, se perciben
indefensas y susceptibles en la medida en que son intervenidas
por patrones de consumo, tecnologías y necesidades que vienen
de fuera sin considerar su contexto sociocultural.
En países en vías de desarrollo, esta situación causa
preocupación porque es uno de los factores que llevan a hombres
y mujeres, que se perciben indefensos, a trasladarse a las grandes
ciudades dejando atrás un mundo de posibilidades y
enfrentando otro de restricciones y discriminación social.
Se desprende de aquí la necesidad de que las investigaciones
sobre recursos genéticos presten tanta atención a los factores
socioculturales que influyen en una comunidad como a la la
utilización y conservación de esos recursos. De este modo se
estaría contribuyendo a la conservación del germoplasma vegetal
y animal en beneficio de las comunidades mismas y de la
sociedad en general. En relación con los aspectos socioculturales,
Ulloa (1995) señala que en las comunidades rurales hay un
“simil de los bancos de germoplasma; es la memoria colectiva,
donde están depositadas informaciones que vienen de
generación en generación y que se mantienen en el tiempo
gracias a un vehículo que se conoce como tradición oral. Los
datos de este banco son codificados de manera peculiar y su
acceso e interpretación requiere n, como en todo banco de
información, de algunos criterios y destrezas y del dominio de
ramas del conocimiento.”
Consideramos, por tanto, que la investigación etnográfica es
aplicable a este tipo de trabajo porque brinda la posibilidad de
utilizar técnicas sencillas y de desarrollar destrezas para aprender
de esa memoria colectiva y respetarla. Consideramos, además,
que la etnografía, como rama fundamental del conocimiento de la
antropología cultural y social, puede ayudar a los equipos que
investigan en recursos fitogenéticos en la conservación y el uso del
germoplasma vegetal a través de la participación justa y equitativa
de los productores y productoras rurales. Se perciben, sin duda,
limitaciones en cuanto a la sistematización de la información, que
no es estándar, pero esto podría mejorar en la medida en que los
equipos de investigación hagan uso de ella.
Materiales colectados
Se colectaron 21 materiales, a saber: 13 de Phaseolus vulgaris, 2 de
Phaseolus lunatus, 5 de Vigna sp., y 1 de Cannavalia sp. Los materiales
fueron entregados al personal encargado de realizar la
caracterización científica completa de cada muestra y de hacer
una comparación con estudios paralelos. El análisis y la
discusión de los resultados quedaron restringidos aquí a la
información suministrada por los productores y a la
determinación, en el laboratorio, de dos características varietales:
el peso de 100 semillas y la forma de la semilla.
Los materiales presentados en el Cuadro 1 son comúnmente
empleados por los productores para las siembras anuales y su
origen es diverso: intercambio de productor a productor, compra
en bodegas, compra en las algodoneras, conservada por familias
de generación en generación como si fuera patrimonio familiar.
Los criterios empleados por los productores para seleccionar
las semillas son: buen tamaño y buen color, y no tener picaduras;
para conservarlas, el método más común es dejarlas secar bien y
luego guardarlas en ‘pipotes´, ‘tamboras´, botellas plásticas
(Figura 2) y sacos; se les agrega a veces ceniza y se colocan en un
lugar alto y apartado de los animales.
Fig.2. Diversidad de materiales locales de Phaseolus vulgaris y Vigna sp Seleccinados y Conservados por los
productores de la zona visitadas.
32
Cuadro 1. Material de leguminosas colectado en las vegas del río Orinoco, Estado Guárico, Venezuela, en 1999
Entrada (no.)
Origen del cultivar
Nombre local
Lugar de la colecta
99-056
99-057
99-058
99-059
De
De
De
De
Tapiramo, Tavaita
Caraota blanca
Vaina de acero, Media rama
Tapiramo, Tavaita
99-060
99-061
De generación en generación
De generación en generación,
10 años
Compró a vendedor de grano
Canavalia
Fríjol negro
Parmana, sector El Brisote
Parmana
Cedeño
Sector Isla de López, Municipio
Cedeño, Edo. Bolívar
Sector Robo Pelao
Sector Robo Pelao
Compró a otro productor
Compro en bodega
Guardada de generación
en generación
Guardada por el productor
hace 10 años
Guardado por el productor
Consiguió hace 3 años, se lo
dio a otro productor
Compró a otro productor
Comprada a la algodonera
Fríjol Vaina de acero
Caraota blanca
Caraota pintada
Caraota negra
Caraota blanca de Bejuco
Sector Isla de López, Municipio
Cedeño, Edo. Bolívar
Vega la Guacamaya, Parmana
Vega la Guacamaya
Vega la Guacamaya
Parmana
Vega, Isla de López
Caraota Pintada
Sector El Burro
Fríjol vaina de acero
Fríjol
Frijol Bejuco
Parmana
Sector El Burro
Sector El Burro
Caraota
Caraota
Frijol
Caraota
Caraota
Parmana
El Burro
El Burro
Isla El Baulito
El Burro
99-062
99-063
99-064
99-065
99-066
99-067
99-068
99-069
99-070
99-071
99-072
99-073
99-074
99-075
99-076
generación
generación
generación
generación
en
en
en
en
generación
generación
generación
generación
Caraota pintada
En el caso del cultivo de Phaseolus vulgaris ¾denominado
caraota, solamente en Venezuela, según un vocablo autóctono
de la lengua caribe (Voysest 1983)¾ se presentan diversos colores
de semilla; los productores las clasifican por ello en caraotas
negras, caraotas rojas, caraotas blancas y caraotas pintadas.
Estas ultimas presentan distintas tonalidades que van del crema
suave con manchas café rojizo al amarillo azufrado con manchas
café rojizo. En el Cuadro 2 se muestran dos de las características
determinadas en el laboratorio, o sea, la forma y el peso de 100
semillas, según los descriptores varietales del CIAT (1993).
En los materiales de Phaseolus, la forma predominante es la de
semilla arriñonada y recta en el lado del hilo (8); viene enseguida
la forma ovoide (2). El peso varía de 14.12 g y 34.16 g por 100
semillas, lo que indica que se trata de semillas de medianas a
pequeñas. Se consumen cuando el grano está seco; las de mayor
preferencia en el consumo son las negras por su fácil y rápida
cocción y por su sencilla preparación, pues su sabor no depende
mucho de la cantidad o variedad de condimentos. Otra caraota
preferida por los consumidores es la pintada; sin embargo,
requiere de más preparación, o sea, cambio de varias aguas de
cocción para eliminar el sabor amargo así como mayor cantidad
y variedad de condimentos. En los dos materiales de Phaseolus
lunatus, llamado comúnmente frijol tapiramo, se identificó un
solo color crema oscuro con manchas café oscuro, con granos de
forma arriñonada y ovoide, con un peso promedio de 32.29 g, de
tamaño grande. Este grano se consume seco y es más exigente en
la preparación y sazón; sus hojas se usan con fines medicinales.
El material de Cannavalia sp. es la semilla de mayor tamaño con
un peso de 64. 37 g, es de color blanco y de forma arriñonada y
recta en el lado del hilo(8). Este material se usa comúnmente en
negra
blanca
roja
negra
la zona del estudio para la alimentación del ganado y como
abono verde.
El material Vigna unguiculata es comúnmente denominado por
los productores de la zona fríjol vaina de acero, fríjol media rama
y fríjol bejuco; el color del grano varía de café rojizo claro a café
oscuro. Las formas que predominan son la pequeña casi
cuadrada (4), la ovoide (2) y la arriñonada (8). El peso de estos
granos está entre 9.79 y 17.62 g, lo que indica que son los
materiales más pequeños de la colecta. Según información de los
productores, este es el grano que más se consume tanto en la
zona estudiada como en el Estado Guárico, en sopa o
acompañado, según la disponibilidad de recursos, de otros
alimentos como plátano, pescado o carne seca. Otra forma de
preparación es la mezcla de fríjol con arroz, lo que hace un plato
típico de la región denominado “palo a pique”. Este grano se
consume más que la caraota, por las siguientes razones:
- como la caraota, es fácil de preparar y su sabor es también
especial pues no requiere de la cantidad y variedad de
condimentos que exigen otros granos;
- el cultivo de la caraota es muy delicado y exigente mientras
que el fríjol bejuco es más suave, su cultivo no exige muchos
cuidados y es más resistente a plagas y enfermedades;
- el fríjol bejuco se adapta a cualquier condición de clima y
suelo por lo que se puede
producir tanto para el mercado como para la familia;
- en cuanto al valor nutritivo, los productores de la zona
consideran el fríjol bejuco equivalente a la carne para la fuerza
de trabajo.
Esto indica que los criterios con que los productores de la zona
de colecta eligen, para la siembra y el consumo, un material
como el fríjol bejuco, tiene una lógica que merece atención y
podría interesar a los fitomejoradores para incluirla en sus
proyectos de investigación.
En relación con las prácticas agronómicas, se observó la
variación de las distancias de siembra según el cultivo; las
prácticas más comunes están centradas en la preparación del
terreno. Los productores, al bajar las aguas del río Orinoco
desde el mes de septiembre, comienzan las labores de
preparación haciendo una limpieza del terreno, que consiste en
eliminar las malezas con machete o herbicida o mediante la
quema; hecho esto, siembran el fríjol. En algunos casos, todas
las labores se realizan el mismo día y en otros se siembra de dos
a tres días después de desmalezar, sobre terreno plano que va
desde ½ ha hasta 4 ha o más.
La siembra tiene dos modalidades: asocian el fríjol con otros
cultivos, como el algodón o el maíz, o en monocultivo. La
práctica más común es ‘a coa´, es decir, el agricultor abre, con
una vara larga, el sitio en el suelo para la semilla y coloca en él de
4 a 5 semillas. En la siembra de la caraota se observaron
distancias de hasta 30 cm entre plantas y 70 cm entre hileras
(calles). En el caso de la caraota pintada, las distancia son de 1
m entre plantas y 3 m entre calles. Ninguno de los productores
entrevistados manifestó que aplicaba fertilizantes y sólo se
refirieron al mantenimiento, que consiste en observar el cultivo
durante todo el ciclo para detectar un ataque de plagas o
enfermedades, y controlar las malezas cuando lo creen necesario;
así transcurren los 4 meses del cultivo y luego proceden a
cosechar.
Respecto a las características socioculturales y económicas
de los productores y productoras de fríjol, el cultivo de estos
granos representa una estrategia de seguridad para la familia
puesto que su producción garantiza el consumo familiar
abastecido durante todo el año y también el ingreso que entra
por la venta de excedente para el mercado local. Se observó que
en el grupo familiar los hijos o familiares cercanos son la
principal fuente de mano de obra; la siguen los contratos
temporales. Lasa mujeres juegan un papel determinante tanto
en su labor reproductiva (mantenimiento del hogar,
preparación de alimentos, cuidado de los niños) como en el
trabajo productivo; se observó que las mujeres hacen labores
de siembra, y algunos productores manifiestan que son más
cuidadosas y dedicadas en estos trabajos. En general, la
producción de granos de la zona es manejada generalmente
por los hombres ya sea con mano de obra familiar, contratada
o de otra modalidad, según sus necesidades. Respecto a la
comercialización de los granos, se observó que suelen venderse
a intermediarios que llegan a la zona y fijan el precio y la
cantidad que compran. Esta situación preocupa a los
productores, quienes manifestaron tener serias dificultades
para vender sus cosechas pues consideran no que no reciben
un precio justo.
Los análisis del suelo de la zona de colecta (Cuadro 3)
indican condiciones de fertilidad de intermedia a alta. El fósforo
y el calcio disponibles se encuentran en un nivel de medio a alto;
las principales limitantes son los bajos niveles de potasio y la
reacción del suelo, porque se encontró un pH bajo que refleja
una acidez de moderada a alta. Las variables edafológicas
señaladas en el Cuadro 2 han definido, durante muchos años, el
uso dado a las vegas visitadas. Si extrapolamos los estudios
antropológicos de Sanoja y Vargas (1978) a la situación actual,
encontramos que muchos cultivos que en el pasado eran las
principales fuentes alimenticias de los grupos indígenas, como
la yuca, el maíz, la ahuyama y los frijoles, hoy continúan
cultivándose con prácticas adaptadas al ambiente local y que
aun hoy contribuyen a preservarlo.
Las observaciones de campo indican también que el
conocimiento local de los productores de las vegas visitadas se
refleja en la habilidad y destreza de las prácticas agrícolas
desarrolladas bajo circunstancias muy particulares. Estas
prácticas obedecen a las características físiconaturales antes
Cuadro 2. Materiales de leguminosas colectados en las vegas del río Orinoco, Estado Guárico, Venezuela, en 1999
Nombre
local
Entrada
(no.)
Peso de 100
semillas (g)
Formas
Caraota blanca
Vaina de acero, Media rama
Tapiramo, Tavaita
Canavalia
Frijol negro
Caraota pintada
Frijol vaina de acero
Caraota Blanca
Caraota pintada
Caraota negra
Caraota blanca de bejuco
Caraota pintada
Fríjol vaina de acero
Fríjol
Fríjol bejuco
Caraota negra
Caraota blanca
Fríjol
Caraota roja
Caraota negra
99-057
99-058
99-059
99-060
99-061
99-062
99-063
99-064
99-065
99-066
99-067
99-068
99-069
99-070
99-071
99-072
99-073
99-074
99-075
99-076
26.04
13.29
32.70
64.37
14.12
23.12
13.08
34.16
27.93
20.90
27.48
16.90
19.52
15.70
17.62
19.78
30.23
9.79
23.69
31.53
(2) Ovoide
(4) Pequeña, casi cuadrada
(2) Ovoide
(8) Arriñonada, recta en el lado del hilo
(8) Arriñonada, recta en el lado hilo.
(2) Ovoide
(2) Ovoide
(2) Ovoide
(2) Ovoide
(8) Aarriñonada, recta en el lado del hilo
(2) Ovoide
34
Cuadro 3. Resultados de los análisis de suelos con fines de fertilidad hechos en la localidad de Parmana, en
las vegas del Río Orinoco, en marzo de 1999
Variables
Resultados
Método de determinación†
Textura
P (ppm)
K (ppm)
Ca (ppm)
Materia orgánica (%)
pH (1:1.5)
Franco limosa (FL)
11 - 25
40 - 70
338 - 500
1.0 - 1.6
4.5 - 5.0
Bouyoucos
Olsen et al. 1954
Olsen et al. 1954
Morgan
Combustión húmeda, Walkey and Black modificado
Relación suelo:agua es 1:2.5
†
Ver Manual de Métodos y Procedimientos de FONAIAP-CENIAP, Serie D, No.26, Capítulos 4.1 y 5.1, Maracary, Venezuela.
descritas (Cuadro 3), las cuales determinan el aprovechamiento
y uso de los suelos y aguas. Los productores conocen las
ventajas de los suelos de las vegas para la producción de granos
y otros cultivos a bajo costo, en comparación con otros suelos de
la región. Esto justifica el significativo esfuerzo que cada año
hacen estos agricultores cuando trasladan sus familias, casas y
enseres al presentarse el desbordamiento del río Orinoco; pasado
éste, vuelven años tras año.
Conclusiones
Los materiales colectados derivan de un mejoramiento artesanal
centrado en el conocimiento local que tienen los agricultores,
hombres y mujeres, de las vegas de Parmana y Cabruta; ellos, a
través de sus experiencias y sus conocimientos, han contribuido
a la conservación y uso de esos recursos.
Las condiciones de fertilidad, de mediana a alta, que arrojan
los análisis de suelos de la zona de colecta, pueden ser causa de
la permanencia en el tiempo de estos sistemas de producción de
bajos insumos. Por otra parte, los materiales que han
sobrevivido, a pesar de la reacción ácida del suelo, se explicarían
como un fenómeno de adaptación y selección natural.
Los conocimientos locales de los productores de las vegas
visitadas son fuente de valiosa información para colectar,
caracterizar y conservar materiales en los trabajos de recursos
fitogenéticos que se realicen. Ahora bien, el uso de dichos
conocimientos no debe ser unidireccional, ya que se podría
incurrir en una forma de expropiación o aprovechamiento
indebido de los recursos. Es, por tanto, necesario que los centros
de investigación asuman compromisos responsables con las
comunidades rurales a fin de incorporar aspectos o estrategias
que beneficien a la comunidad.
Los materiales colectados son fuente primaria de recursos
alimenticios para el mantenimiento del productor y su núcleo
familiar, quienes utilizan el área per cápita necesaria para la
subsistencia y el mercado local. Todo esto está determinado por
las inundaciones anuales del río Orinoco, que le confieren
características socioculturales muy particulares a la zona, las
cuales deben considerarse a fin de mejorar la calidad de vida de
los agricultores y sus familias.
Referencias
Bentley, J. 1990. Facts, fantasies and failures of farmer
participation: Introduction to the symposium volume En :
Memora del Simposio Participación del Pequeño Agricultor
en la Investigación y Extensión Agrícola, celebrado en la
Escuela Agrícola Panamericana de Zamorano, Honduras.
CEIBA (Honduras) 31(2):7-27.
Bogdan, R. and S. Biklen. 1982 Qualitative research for
education: An introduction to theory and methods. Allyn y
Bacen. p. 70-72.
Chirinos, A.V. and J. Brito. 1985. Muestreo de suelos para
diagnóstico de fertilidad. Serie E, No. 8-02. FONAIAP,
Maracay. p. 18.
Cruz, J. 1996. Saber local, poder y desarrollo humano sostenible.
Bosques, Arboles y Comunidades Rurales (Costa Rica)
27:46-47.
Erickson, F. 1979. Mere ethnography: Some problems in its use in
educational practice. Anthropology and Education
Quarterly:36-42.
Gilabert de Brito, J., López I. de R. y R. Roberti. 1990. Análisis de
suelos para diagnóstico de fertilidad. En: Manual de métodos
y procedimientos de referencia. FONAIAP-ENIAP, Maracay.
Serie D, No. 26.
Martínez, M. 1996. Comportamiento humano: Nuevos métodos
de investigación. 2ª. ed. Trillas, México DF. p. 199-207.
Mathias, E. 1996. Marco para perfeccionar el uso de los
conocimientos locales Bosques, Arboles y Comunidades
Rurales (Costa Rica) 27:42-45.
Maundu, P. 1996. Metodología para recolectar y compartir los
conocimientos locales: Un estudio de caso. Bosques, Arboles
y Comunidades Rurales (Costa Rica) 27:32-36.
Muñoz, G., G. Giraldo y Fernández de Soto J. 1993. Descriptores
varietales: Arroz, frijol, maíz, sorgo. Centro Internacional de
Agricultura Tropical (CIAT), Cali, Colombia. p. 75-78.
Ovalles, F.A. 1992. Metodología para determinar la superficie
representada por muestras tomadas con fines de fertilidad.
Fondo Nacional de Investigaciones Agropecuarias
(FONAIAP) e Instituto de Investigaciones Agrícolas
Generales, Maracay, Venezuela. Serie E. 44 p.
Patton, M. 1980. Qualitative evaluatíon methods. Sage, Beberly
Hill, CA, E. U. p, 24.
Quiroz, Consuelo. 1996. Taller sobre el proceso de la extensión
agrícola y la perspectiva de género. Centro para la Agricultura
Tropical Alternativa y el Desarrollo Integral (CATADI),
Universidad de los Andes, Núcleo Rafael Rangel Trujillo,
Mérida, Venezuela. (Mimeografiado.)
Riera, J. y S. Guerrero. 1984. Diagnóstico agroecológico del
nororiente de Guárico. En: Archivos de la Estación
Experimental Valle de la Pascua, Guárico. FONAIAP,
Venezuela. 184p. (Mimeografiado.)
Sanoja, M. y I. Vargas. 1978. Antiguas formaciones y modos de
producción venezolanos. Monte Avila Editores, Caracas,
Venezuela. p. 106-117.
Ulloa, L. 1996. Proyectos en las comunidades: ¿Construir
escenarios de acción conjunta? Colección Cuadernos de Libre
Opinión. Servicio de Información Mesoamericano sobre
Agricultura Sostenible (SIMA), Managua, Nicaragua. p. 49.
Voysest, O. 1983. Variedades de frijol en América Latina y su
origen. Centro Internacional de Agricultura Tropical (CIAT),
Cali, Colombia. p. 85-87.
Woods, P. 1985. Sociology, ethnography and teacher practice:
Teacher and teacher education. p. 15 –21.
Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No. No.
123:123
35 - 35
40
ARTICLE
A network for the management of genetic resources
of maize populations in France
Jacques Dallard*, Philippe Noël, Brigitte Gouesnard and Armand Boyat
Unité Mixte de Recherche “Diversité et Génome des Plantes Cultivées”, INRA Domaine de Melgueil, 34130 Mauguio,
France. Tel: +33 4 67290617; Fax: +33 4 67293990; Email: [email protected]
Summary
Résumé
Resumen
French maize breeders have for a long
time been aware of the need to save the
genetic variability in maize populations.
In the 1980s they decided to collaborate
in order to study approximately 1315
populations and to equip themselves
with the tools needed for the long-term
conservation and dissemination of materials. A cooperative network was set up
of French maize breeders, including public research and private companies, to
allow the tasks of regeneration, conservation and distribution of materials to be
shared between the members of the network and also with other partners. A
common agreement, the “Charter for
the management of maize genetic resources”, specifies the rights and obligations of the partners. Altogether 25
members regenerate 100 populations
per year. Seeds are desiccated to 7% moisture content and packed in laminated
aluminium-foil bags. Ten samples per
population, containing 600 kernels each,
are conserved in a coldroom at +4°C for
distribution (user samples). Two other
samples are stored for regeneration and
safety purposes in a coldroom at –18°C.
A 25-year conservation period is expected for the user samples. Unlike in other
genebanks, in this cooperative network
genetic resources are managed by maize
professionals from their regeneration to
their dispatch. Thanks to this collaborative network, efficient methods of regeneration and conservation, in line with
the recommendations of IPGRI and the
theoretical developments of population
genetics, can be used.
Les sélectionneurs français ont perçu
depuis longtemps la nécessité de conserver la variabilité génétique des populations de maïs. Dans le cadre d’un programme qui a rassemblé et étudié environ 1315 populations, ils se sont dotés
des équipements nécessaires à la conservation à long terme et à la distribution de
ces ressources génétiques. Un réseau
composé des unités de la recherche publique et des établissements privés de
sélection permet un partage des tâches
pour régénérer, conserver et distribuer
le matériel aux membres du réseau et
aussi à d’autres partenaires. Un accord :
la “ Charte pour la gestion des ressources génétiques de maïs ”, précise les droits
et les obligations de chaque membre.
Actuellement, 25 partenaires régénèrent
chaque année une centaine de populations. Les semences sont déshydratées à
7% d’humidité, puis conditionnées en sachets aluminium. Dix échantillons par
population contenant 600 grains sont
conservés dans une chambre froide à
+4°C pour la distribution. On pense pouvoir les conserver pendant 25 ans. Deux
autres échantillons sont conservés à –
18°C pour la régénération et pour la sécurité. Dans ce réseau coopératif, à la différence d’autres banques de gènes, tous
les travaux, depuis le champ de régénération jusqu’à l’envoi aux utilisateurs, sont
exécutés par des professionnels du maïs.
Grâce à ce réseau coopératif, on utilise
des méthodes efficaces de régénération
et de conservation qui tiennent compte
des recommandations de l’IPGRI et des
approches théoriques de la génétique des
populations.
Los selectionadores franceses de maíz de
han dado cuenta, hace tiempo, de la
necesidad de conservar la variabilidad
genética en poblaciones de maíz. En los
años ochenta, en el marco de un programa que ha agrupado y estudió alrededor
de 1350 poblaciones, se equiparon de los
útiles necesarios para la conservación a
largo plazo y la distribución de estos recursos genéticos. Una red, incluyendo la
investigación pública y empresa privadas de selessión, permite repartir la tareas para regenerar, conservar y distribuir los materiales a los miembros de la
red y también a otros socios. Un acuerdo
común, la “ Carta para la gestión de los
recursos genéticos del maíz “ especifica
los derechos y obligaciones de cada socio. Actualmente, 25 miembros regeneran 4 poblaciones por año cada uno. Los
semillas están deshydratadas a 7% de
humedad y después condicionadas en
bolsas de aluminio. 10 muestras de 600
granos por población están conservada
en una cámara friá a +4° para distribuir.
Dos muestras mas están conservadas a 18° para regeneración y para seguridad.
Se espera un período de conservación de
25 años para las muestras de distribución.
En esta red cooperativa, a diferencia de
otros bancos de genes, todas las operaciones, desde el campo de regeneración
hasta que envia a los usuarios, son ejecutados por professionales del maíz. Gracias a esta red de cooperación, se utilizán
métodos eficaces de regeneración y de
conservación, que tienenen cuenta las
recomendaciones del IPGRI y los estudios teóricos de la genética de las poblaciones.
A network for the management
of genetic resources of maize
populations in France
Un réseau de gestion des
ressources génétiques des
populations de maïs en France
Una red para la gestión de los
recursos genéticos de las
poblaciones de maíz en Francia
Keywords: Ex situ conservation,
genebank, landrace, regeneration,
Zea mays L.
Introduction
Maize is a major crop in France, occupying 3.3 million ha of
farmland; half of which is for silage production. The varied
climatic conditions in France make it possible to crop early
(grain or silage) to late (grain) hybrids. For 40 years, the annual
gain in grain productivity has been 0.12 t ha-1 year-1, of which a
major part is due to an important plant-breeding activity
(AGPM 1994). In fact, increases in the annual production of
maize are due to higher yields rather than increases in acreage.
All cultivated maize varieties are now hybrids. The first
development of maize hybrids began in France at the end of the
1950s, with the selection of the so-called first-cycle inbred lines.
Early inbred lines, developed from European flint kernel populations, in combination with early dent American inbred lines,
produced early hybrids suitable for European cultivation. The
laboratories of the Institut National de la Recherche
Agronomique (INRA) played a very important initial role in
36
developing the first hybrids (INRA 200 in 1957, INRA 258 in
1958, INRA 260 in 1961). Thereafter, private and cooperative
breeding companies further developed this activity by improving lines. This has resulted in continuous genetic progress and a
flow of new varieties throughout northern Europe.
In the 1980s a new interest emerged in landraces. The genetic basis of cultivated maize has narrowed as few genitors are
used in hybrid development. Thus the F2 line, developed from
the Lacaune population in about 1955, is still used and was
present in 85% of the early and medium-early varieties sold in
1990 (Gallais et al. 1992). In 1983 public and private French
maize breeders joined together to collect, maintain, characterize
and evaluate maize landraces adapted to French conditions.
With the financial support of the French Ministries of Scientific
Research and Agriculture, the cooperative programme
“Programme Populations Sources” (PPS) was formed under the
leadership of Professor André Gallais and with the participation of six INRA laboratories1 and 16 private companies belonging to the PRO-MAIS2 association. Approximately 1300 populations of maize adapted to French conditions were included in
the PPS. A description of the programme and its main results
can be found in Gallais et al. (1992), Groupe Maïs DGAP-INRA,
PROMAIS (1994) and Gallais and Monod (1998).
Since 1993, the collection of maize population genetic resources has been managed through a maize network, with regeneration being carried out through an association of public and
private maize breeders. The network’s regulations for the management and distribution of the genetic resources of maize are defined in a charter under the aegis of the Bureau des Ressources
Génétiques (BRG)3, derived from the general charter for French
genetic resources (http://www.brg.prd.fr/brg/ecrans/charte).
This article presents the partners in the network, describes
the technical and organizational aspects of the programme
(regeneration, germination tests, medium- and long-term conservation) and discusses the advantages and disadvantages of
such an organization. Guidelines for the distribution of material
are also given.
Maize populations
The maize populations conserved are described in Table 1 according to their collection status and genetic type. All the French
landraces still available and some French public synthetics are
in the national collection. Although French landraces are well
adapted to growing conditions they have not been grown as
crops in France for about 30 years. In the 1950s and 1960s
landraces were collected mainly by the INRA stations of
Clermont-Ferrand, Saint-Martin-de-Hinx and Montpellier,
The INRA units of Mons en Chaussée, Le Moulon, Lusignan,
Clermont-Ferrand, Montpellier and Saint-Martin-de-Hinx.
2 Members of Pro-Maïs involved in PPS: CACBA, CARGILL
(SEMENCES), CAUSSADE SEMENCES, CIBA-GEIGY,
FRANCE CANADA SEMENCES, GIE EUROMAIS, ICI SEEDS,
LIMAGRAIN, MAÏSADOUR, NICKERSON, NORTHRUP-KING
SEMENCES, ORSEM, PIONEER FRANCE, RAGT, RUSTICA
SEMENCES, SDME.
3 Bureau des Ressources Génétiques, 15 rue Claude Bernard, 75231 Paris cedex 05. http://www.brg.prd.fr/brg
1
mainly from the Pyrenean area, the Garonne valley, and Poitou,
Bresse and Alsace, the areas where maize was traditionally
grown. All these regions, which are characterized by rainy summers, are favourable for maize cultivation. Most French
landraces are flint-type corn, of which 40% are white kernels.
The genetic variability of all French landraces was studied by
using morphological traits (Gouesnard et al. 1997).
In addition to maize populations cultivated in France, other
populations have been obtained through exchanges with national institutions. These are mostly early or medium-early maturing varieties, many of which originated in Eastern Europe
and were chosen for their adaptability to French conditions
Genepools derived from populations are also included in the
collection. These have been formed by intercrossing 20 to 40
populations selected on the basis of utilization. Grain, forageyield performance, earliness and combining ability were taken
into account. A large part of the pools were then crossed with
elite materials in order to improve their agronomic traits.
The network
The network includes the PRO-MAÏS private companies and
INRA stations distributed throughout France (see Fig. 1). PROMAIS (Association pour l’Etude et l’Amélioration du Maïs) is a
private association, created in the 1960s, which gathers together
all the seed companies carrying out maize breeding in France
and working in the European market. The list of the 18 PROMAIS members for the year 2000 is given in Table 2.
Its structure enables French private breeders and INRA scientists to combine resources and knowledge to carry out reTable 1. Origin and type of managed populations
Collection
status
Landraces
Synthetics
National
collection
Network
collection
Total
270
60
648
918
Genepools Total
–
330
267
74
985
327
74
1315
Table 2. Member companies of PRO-MAIS
ADVANTA France
ASGROW Monsanto SAS
CARGILL Monsanto SAS
CAUSSADE SEMENCES
CEBECO SEMENCES
CORN STATES INTERNATIONAL
GOLDEN HARVEST - ZELDER
LIMAGRAIN GENETICS
MAÏSADOUR SEMENCES
NICKERSON SEMENCES
NORDSAAT France
NOVARTIS SEEDS
PAU SEMENCES
PIONEER GENETIQUE
R.A.G.T. SEMENCES
RUSTICA PROGRAIN GENETIQUE
S.D.M.E./K.W.S. France
VERNEUIL RECHERCHES
data files. The network is experienced in
maize experimentation and knowledgeable about maize variability and the
breeding process. It has also gained experience in managing a genebank.
Regeneration
Scientific basis
The main objective when regenerating
germplasm is to avoid any loss of genetic diversity due to random genetic
drift, subsequent inbreeding or loss of
seed viability. However, this process has
to be carried out under a programme
constrained by limited funding.
From studying population genetic
theory Crossa (1989), Crossa and
Vencovsky (1994) and Crossa et al.
(1994) evolved practical methods of
seed regeneration for maize or monoecious species. Theoretical developments
are based on the concept of effective
population size (Ne), i.e. that the size of
a population is the size of a theoretical
population with the same inbreeding
coefficient, or the same allelic frequency
variance, as that of the actual or hypothetical population under study. For a
large mating population the effective
population size can be defined as the
number of progenitors contributing to
the next generation (also called effective
genitors). The number of effective
genitors, sex ratio and variation in the
number of offspring, influence effective
population size (Crossa and Vencovsky
Fig 1. Regeneration sites of maize landraces in France. Source: P. Ruaud
1994). These considerations have to be
taken into account when defining the
search to serve the common long-term interests of maize breed- number of conserved seeds, the mating design and the number
ers and not just research for short-term profit. Projects are of seeds sampled on ears in order to constitute a seed set for
proposed by the Genetic and Plant Breeding Department of conservation.
INRA and managed by PRO-MAÏS and INRA together, under a
To determine the number of seeds to be conserved for each
general agreement for the regulation of research projects, paying accession, an analysis of genetic drift can be carried out considcareful attention to issues such as Intellectual Property Rights.
ering the probability of keeping an allele for a locus. Based on a
Most of the activities are developed with only some of the random mating population of infinite size and a Hardy
members through a research clause included in the general agree- Weinberg equilibrium for independent loci, Crossa et al. (1993)
ment. PPS, which operated between 1983 and 1993, was just such found that this probability was influenced much more by the
a programme. Two long-term and compulsory activities are imple- sample size of parents and the frequencies of the rarest alleles
mented by all members: experimentation of new inbred lines than by the number of alleles per locus. For example, the sample
developed by INRA (GELI, Groupe d’Etude des Lignées INRA) size should be greater than 400 to preserve, with 95% probabiland regeneration of maize populations conserved in Montpellier. ity, four alleles per locus with the rarest at 1% frequency. Under
The latter activity is the subject of this paper.
the same conditions, a sample size of 80 would be sufficient for
For this project the network is constituted by PRO-MAÏS a frequency of 5%. The loss of an allele has an incidence upon
and the six INRA maize units; work is coordinated by the staff the reduction of heterozygosity. In general, the rate of change
of the INRA maize unit at Montpellier. Besides the common task from x alleles to x-1 alleles (inbreeding rate) is F= x(x-1)/4Ne
of regeneration, the team deals with seed conservation and (Kimura 1955). Frankel and Soul (1981) suggested that the rate
distribution, and with documentation through catalogues and should not be higher than 1%.
38
A full-sib mating design using plants as females or males
but not both, ensures the control of the number of genitors and
the equality of their sex ratio. Such a mating design maximizes
the effective population size for a given number of progenitors.
In this case, Ne=2Nt (Nt being the number of offspring in generation t), for a population in a Hardy Weinberg equilibrium with
an equal contribution of parents and when all seeds give descendants (Crossa and Vencovsky 1994). In a mating design
with random pollination and a controlled number of female
progenitors the effective population size is lower than in full-sib
mating design (Ne=4/3Nt with the same assumptions). For a
limited number of progenitors the full-sib mating design is
better than isolation field design.
Selection during regeneration has contrasting effects:
favourable when the mutation accumulation is considered and
unfavourable when the evolution of population size is considered, expressed by the number of effective progenitors. Schoen et
al. (1998) have investigated the impact of the regeneration procedure on mutation accumulation. They found that mutation
numbers per genome increased significantly in sample sizes less
than 75 or equalization of seed production by individual plants.
With a number of viable seeds higher than the number of
genitors, a selection step may occur during regeneration. Thus,
the genetic load is maintained at an acceptable level.
Implementation
The following protocol of full-sib mating design is used in order
to limit random genetic drift, preserve the increase of the inbreeding rate and limit mutation accumulation. For each population 500 to 600 kernels are sown at two planting dates, the
second date at the emergence of the first. The two planting dates
make crosses possible between plants of different earliness and
favour panmixia. Both tassels and ears are bagged and pollination is carried out manually. Each plant is used once only as a
female or a male but not both. The aim is to produce 200 ears per
population. The conservation sample is a 600-kernel balanced
sample composed by collecting 3 kernels from each of 200 ears.
When less than 200 ears are obtained, more kernels are picked
from each ear in order to maintain a 600-kernel sample. The
accession is replanted the following season if less than 100 ears
are obtained. Twelve samples are made up in this way and the
remaining seeds are bulked.
As each company has its own methods of working, the
above compulsory protocol of cropping and managing the regeneration process was agreed on by the association in order to
prevent discrepancies. In this way, all the partners use the same
method. The standardized sets of seeds produced according to
the agreed full-sib method are delivered to the conservation
unit. Only the number of ears is allowed to fluctuate (between
100 to 200). Of course, this is laborious and time-consuming
work with no immediate financial return. However, the awareness of members that the participation of each component of the
network is needed for the long-term common good ensures that
companies agree to this programme.
During regeneration, sowing date, emergence rate, silking
date, height, lodging, smut, stay-green and other stresses, if
any, are recorded. All these data are then cross-referenced to a
control hybrid present in the field and the effective number of
used ears per balanced sample is recorded.
Results
For the past six years, population regeneration has made it
possible to obtain 39% of populations with 100 to 150 ears,
35% with 150 to 200 and 26% with 200 ears. On average, from
550 sown seeds, 440 fertile plants and 163 full-sib ears are
cropped. In the worst-case scenario, 385 plants and 100 fullsib ears are obtained. Since the seed sample is constituted by
bulking three to six kernels per ear, it is possible that in the
next regeneration plants from the same ear are crossed. However, as the probability of this happening is low: 0.003 and
0.008 for 200 and 100 ears respectively, it can be assumed that
the risk is negligible.
Below, one regeneration is considered as a step within a
scheme with a constant population size so that Nt=Nt-1 (Crossa
and Vencovsky 1994). We will assume that the mean allele
number per locus is four. This number could be considered as an
average situation between isozyme and RFLP loci (Dubreuil and
Charcosset 1998).
Three scenarios are considered: the best, the average and the
worst, depending on the number of ears cropped (Table 3). Ne is
given by the equation N e=N*2u/(2-u) (Crossa and Vencovsky
1994) where u is the ratio of the number of effective genitors on
the number of progenitors or sown seeds (=550). Whatever the
number of independent loci, any regeneration saves alleles at 5%
frequency with 95% probability. However, only in the best-case
scenario is a probability level of 1% frequency obtained. In any
situation a number of potential genitor plants will be rejected:
48% in the worst-case scenario, 26% on average and 12% in the
best case. Thus, selection against deleterious mutations always
occurs.
Table 3. Regeneration: probability of retaining four alleles per locus, according to sample size, for 550 germinated seeds and five loci
Situation
Number
of ears
Sample
size
U†
Lower borderline
Medium case
Optimum case
100
163
200
200
326
400
0.36
0.60
0.73
†
ratio of effective genitors: sown progenitors
‡
Effective
population
size
Inbreeding
rate
Frequency
of alleles
Ne
241
471
632
F
1.2%
0.6%
0.5%
1%
<90%
90% (b) §
95% (b) §
(a) loci number <5
§
(b): for 1 locus
3%
95% (a)‡
95%
95%
5%
95%
95%
95%
Seed processing
When a sample is added to the long-term genebank collection,
the quality of seeds, including both their genetic and physical
characteristics, must be checked. To do this, the following operations are carried out: sampling, check of purity, check of
germination rate, drying, packing and labelling.
After harvesting, seed is dried to 12-15% moisture content
by a conventional dryer at 40°C. The balanced samples are then
made up and sent to the conservation unit. Here samples are
visually compared with previous samples in order to identify
any pollution or error. Scored data are investigated.
Germination tests
The germination tests are carried out on two occasions: (1) at the
receipt of a population after regeneration on two replicates of
100 remnant bulked seeds and (2) on each population every 10
years by sequential tests on 50 seeds from a user sample. The
methods and norms used for commercial seeds (ISTA rules)
seem to be poorly adapted to populations because in general,
genetic resources have low germination energy and a high rate
of fungal infection. We now use the method described below.
On an enclosed plastic tray (60 cm x 40 cm x 7 cm) grains are
distributed between two blotting paper layers. This size tray
makes it possible to lay out 400 grains with enough space
between them. Distilled water is then added and the trays are
put in a room under the following conditions: 12 hours at 25°C
with light and 12 hours at 18°C in the dark. Relative humidity is
always kept higher than 85%.
The germination rate is established with the proportion of
normal and delayed seedlings after seven days. A poor relationship was observed between the germination rate in the laboratory and the emergence rate in the field. For this reason, traits
such as delayed seedlings and fungal infection are also taken
into account. When the germination rate is lower than 90%, or
the percentage of fungal-infected seeds is greater than 35%, the
regeneration process is carried out again the following year.
Annually, approximately 5% of the populations have to be
regenerated again due to germination deficiency.
Seed drying
Studies have highlighted the predominant influence of moisture
content on seed ageing (IPGRI 1985; Roberts 1989). Therefore, a
significant effort was made to lower the moisture content of
seeds and to keep them in waterproof cans.
In the drying room a dehumidifier is used which uses the
absorption properties of lithium chloride. Grain is packed into
net bags and during the first stage (one month) the drier is
maintained at +15°C and 15% RH. For the next month conditions are maintained at +20°C and 10% R.H; the grain moisture
content is then near 7%. The drying time for drying maize grain
is long compared with other seeds because of the high seed
weight.
Seed packing
After drying, each unit of 600 kernels is packed in a laminated
foil bag and immediately sealed and stored in the coldroom. The
bag consists of four layers: an outer layer of 50 g/m2 paper, a
layer of 12 g/m2 polyethylene, followed by a layer of 15 µm
aluminium foil and an inner layer of 36 g/m2 polyethylene. The
polyethylene provides the sealing properties and the aluminium
provides a barrier to moisture. In this way the seeds are maintained at 7% moisture content.
Conservation and stock management
Ten bags constitute the medium-term user samples destined to
be distributed and preserved in the coldroom at +4°C. Their
conservation time is assumed to be around 25 years. Two bags
are kept for long-term conservation. The first is stored in a
domestic refrigerator at -20°C at Mauguio, the second in a hired
commercial coldroom at -18°C. This should ensure conservation
for approximately 50 years.
Distribution of germplasm
Requests for material by users should be made in writing giving
the proposed use. All materials conserved are free and available
to members of the network. For others, the national collection is
only available on the basis of reciprocal exchange. The sole
condition laid down is that users of the material are required to
report the data they gather on the germplasm received. This
allows us to improve our knowledge of the material and its
adaptability to different environments.
Information management
The information is managed with an application built on an
ACCESS package. This allows for the identification of populations, and the management of passport data and some primary
data. It is also used for stock management, the management of
annual regeneration and the distribution of material. Therefore,
it is possible to trace back the dates, destination, nature and
amount of germplasm distributed in previous years. Paper
records are also kept. An Index Seminum, implemented by the
Unité de Recherche de Génétique et Amélioration des Plantes,
describes the germplasm in the national collection and is widely
distributed.
Discussion and conclusion
A main feature of this network is that maize professionals,
within the framework of the plant-breeding network, are responsible for implementing the management of the genetic
resources and not genebank specialists (Lefort et al. 1997). Therefore, nobody works full time on this activity. The disadvantage
is that in the past, some problems occurred due to the lack of
specific equipment or to poor knowledge of conservation practices. The advantage is that network members are knowledgeable about maize and the use of genetic resources by breeders.
One interesting aspect of this network is the implication for
French maize breeders, all of whom are committed to the task of
regeneration through the “Charte pour la gestion des ressources
génétiques du maïs”. Thanks to the number of regenerators
involved, an efficient, but highly time-consuming and expensive method can be used. This would not be possible if only one
public unit was involved in the project. In addition, all breeders
have the opportunity to handle genetic resource materials and
are aware that they are participating in a collective investment.
40
Thus they are encouraged to use genetic resources in their
respective breeding programmes. From the regeneration point of
view, the distribution of regeneration locations in varied latitudes and climates (from 43°60’N to 50°N) permits the regeneration of the maize population collection with a high degree of
earliness, from 700 to 1100 Growing Degree Units to female
flowering.
The regeneration and conservation costs have been evaluated for French genetic resources (Burstin et al. 1997). For maize
alone, the regeneration step, at around 600 Euros per regeneration or 24 Euros per population per year, is clearly more expensive than the conservation step at 8 Euros per population per
year. Therefore, our strategy will be to space out the regeneration
as much as possible, to keep seed on a long-term basis and to
manage the collection in such a way as to provide enough seeds
to respond to requests.
To manage the collection of French maize landraces a core
collection of 80 populations has been constituted. Based on
morphological and passport data, sampling is done by following the MSTRAT method (Gouesnard et al. unpublished). A
number of classes of variables is used as a diversity index to
maximize the allelic richness. Sampling commenced with a
small number of early maize populations used in the development of first-cycle inbred lines. The aim is to favour germplasm
utilization and to lower conservation costs. In future we could
preserve all the germplasm deep-frozen for the long term,
while making the core collection easily available to breeders for
both quality selection and quantity of seeds. Our knowledge of
the genetic variability of the core collection has also been
enhanced by studies on neutral polymorphism (RFLP and
micro-satellites).
References
AGPM. 1994. Association Générale des Producteurs de Maïs. Le
maïs. Septembre 1994.
Burstin, J., M. Lefort, M. Mitteau, A. Sontot and J. Guiard. 1997.
Towards the assessment of the cost of genebank management: conservation, regeneration and characterization. Plant
Var. Seeds 10:163-172.
Crossa, J., C.M. Hernandez, P. Bretting, S.A. Eberhart, and S.
Taba. 1993. Statistical genetic considerations for maintaining
germplasm collections. Theor. Appl. Genet. 86:673-678.
Crossa, J. and R. Vencovsky. 1994. Implications of the variance
effective population size on the genetic conservation of monoecious species. Theor. Appl. Genet. 89:936-42.
Crossa, J. 1989. Methodologies for estimating the sample size
required for genetic conservation of outbreeding crops. Theor.
Appl. Genet. 77:153-161.
Dubreuil, P. and A. Charcosset. 1998. Genetic diversity within
and among maize populations: a comparison between
isozyme and nuclear RFLP loci. Theor. Appl. Genet. 96: 577587.
Frankel, O.H. and M.E. Soule. 1981. Conservation and evolution.
Cambridge University Press, Cambridge, UK.
Gallais, A., H. Duval, P. Garnier and A. Charcosset. 1992. Un
exemple de gestion des ressources génétiques en vue de la
sélection. Pp. 468-477 in Complexes d’espèces, flux de gènes
et ressources génétiques des plantes. Colloque international,
Paris, 8-10 janvier 1992. BRG, Paris, France.
Gallais, A. and J.P. Monod. 1998. La gestion des ressources
génétiques maïs en France: de leur caractérisation jusqu’aux
premiers stades de leur valorisation. C.R. Acad. Agric. Fr.,
1998, n°3, pp. 173-181. Séance du 6 mai 1998.
Gouesnard, B., J. Dallard, A. Panouille and A. Boyat. 1997.
Classification of French maize populations based on morphological traits. Agronomie 17:491-498.
Groupe Mais DGAP-INRA, PROMAIS. 1994. Cooperative program for management and utilization of maize genetic resources. Meeting of EUCARPIA, 15-18 March 1994,
Clermont-Ferrand, France.
IPGRI. 1985. Handbook of seed technology for genebanks. IPGRI,
Rome, Italy.
Kimura, M. 1955. Random genetic drift in a multi-allelic locus.
Evolution 9:419-435.
Lefort, M., M. Chauvet, Y. Dattee, J. Guiard, M. Mitteau and A.
Sontot. 1997. The French strategy for the management of
plant genetic resources. Plant Var. Seeds 10:153-162.
Roberts, E.H. 1989. Seed storage for genetic conservation. Plant
Today 2:12-17.
Schoen D.J., J.L. David and T.M. Bataillon. 1998. Deleterious
mutation accumulation and the regeneration of genetic resources. Proc. Nat. Acad. Sci. USA 95:394-9.
Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No. No.
123:123
41 - 41
45
ARTICLE
Caracterización por cianogénesis de una colección
de trébol blanco (Trifolium repens L.) en Pergamino,
Argentina
E.M. Pagano y B.S. Rosso*
Estación Experimental Agropecuaria del INTA, C.C. 31, 2700-Pergamino, República Argentina.
Resumen
Caracterización por
cianogénesis de una colección
de trébol blanco (Trifolium
repens L.) en Pergamino,
Argentina
La concentración de ácido cianhídrico es
una característica del trébol blanco que
varía entre poblaciones y entre las plantas dentro de una población, y cuya distribución resulta afectada por distintas
fuerzas de selección, siendo la temperatura la de mayor importancia. Con el fin
de utilizar este carácter en la descripción
de una colección de esta especie, se calculó la frecuencia de plantas que presentan esta condición en 53 poblaciones de
trébol blanco (Trifolium repens L.) naturalizadas, recolectadas en Argentina, y
en 21 poblaciones introducidas. El porcentaje de plantas cianogénicas en las
poblaciones colectadas tendió a ser alto.
Sólo dos poblaciones presentaron una
menor proporción de fenotipos cianogénicos (40%). La única correlación significativa encontrada fue con el carácter
precocidad. La intensidad de la reacción
indicó que la mayoría de las poblaciones
colectadas presenta formas cianogénicas
leves y moderadas, a diferencia de las
introducciones. En éstas se exceptúan las
de Australia, en las que se observó una
alta frecuencia de formas acianogénicas.
Résumé
Summary
La concentration d’acide cyanhydrique
est une caractéristique du trèfle blanc qui
montre des variations entre populations
et aussi a l’intérieur des populations. La
distribution de cet acide est affectée par
plusieurs facteurs de sélection étant la
température le plus important. Avec le
but de se servir de ce caractère pou décrire une collection de cette espèce on a
établie la fréquence de plantes qui montrent ce condition sur 53 populations de
trèfle blanc (Trifolium repens L.) collecté
dans Argentine, et 21 populations exotiques. Le pourcentage de plantes cyanogénétiques pour l’ensemble des populations collectés était haut. Seulement 2
populations montraient une proportion
plus faible de phénotypes cyanogénétiques (40%). L’unique corrélation positive trouvée a été avec précocité. La classification selon l’intensité de la réaction a
montré des formes cyanogénétiques peu
importantes et modérées dans la plupart
des populations. D’un autre côté, la plupart des populations exotiques a montrée une haute fréquence de formes acyanogénétiques, exception faite des australiennes.
Cyanide production (CP) in white clover
accessions varies among populations and
among plants within populations. Several factors affect CP distribution and
temperature is the most important. In
order to use this character to describe a
germplasm collection of this species, the
frequency of cyanogenic plants was
evaluated in 53 naturalized populations
collected in Argentina and in 21 introduced populations. The percentage of
cyanogenic plants was high in the naturalized populations. Only two populations showed a lower proportion (40%)
of cyanogenic phenotypes. Earliness was
the only variable showing significant correlation with cyanogenesis. Reaction intensity indicated that most naturalized
populations had low and moderate
scores compared to introduced populations, except those from Australia, which
had a high frequency of acyanogenic
populations.
Caractérization cyanogénétique
d’une collection de trèfle blanc
(Trifolium repens L.) à
Pergamino, Argentine
Introducción
Como ocurre en otras 2000 especies vegetales, en las poblaciones
de trébol blanco (Trifolium repens L.) hay una proporción variable
de individuos capaces de liberar ácido cianhídrico (HCN). El
follaje de muchas plantas de trébol blanco libera HCN cuando
sus hojas sufren daños y este proceso se denomina cianogénesis.
El HCN resulta nocivo para la planta; por ello no está presente
como tal, sino que se produce por la acción de una enzima
hidrolítica (la beta-glucosidasa) que hidroliza un glucósido
cianogénico y el final de esta reacción es la liberación de HCN.
Estos sustratos cianogénicos (lotoaustralina y linamarina) están
almacenados en la vacuola mientras que la(s) enzima(s)
correspondiente(s) se ubican a menudo en la pared celular. Por
esta razón, el HCN se produce únicamente cuando se destruyen
las células, condición en que el material vegetal empieza a
contener un compuesto tóxico. Si bien el rumiante dispone de
mecanismos que permiten transformar el HCN, cuando la
cantidad de ácido absorbida es muy alta, el mecanismo de
desintoxicación se satura y el riesgo de enfermedad por
Cyanogenic characterization
of a white clover (Trifolium
repens L.) collection in
Pergamino, Argentina
Key words: Characterization, collection, cyanogenesis, populations, Trifolium repens, white clover
intoxicación es mucho mayor (Lehmann et al. 1991).
La herencia de la cianogénesis en el trébol blanco es diploide
(Corkill 1942) dando lugar a dos fenotipos: uno cianogénico,
que depende genéticamente de la presencia de dos genes
complementarios en estado de dominancia (fenotipo Ac-Li-), y
otro acianogénico, que se da en tres categorías: a) ausencia de
cianoglucósidos, b) ausencia de linamarasa, y c) ausencia de
ambos (fenotipos ac-Li, Ac-li y ac-li).
El nivel de actividad cianogénica varía entre plantas
diferentes y hay evidencia de que la variación cuantitativa en el
contenido del glucósido depende, en parte, de la condición
heterocigota u homocigota de estos genes; por tanto, la condición
Ac/ac y la Li/li tendría distinto efecto que Ac/Ac y Li/- y daría
lugar a distintas cantidades de HCN liberado (Hughes 1991).
Por otra parte, se ha encontrado que esa variación cuantitativa
se debe parcialmente a la existencia de diferentes alelos Ac y Li,
los cuales determinan distintos niveles de actividad enzimática
y de contenido de glucósido (Hughes et al. 1984).
42
El polimorfismo cianogénico del trébol blanco interesa a los
mejoradores porque, según las primeras investigaciones, el
rendimiento de forraje y la persistencia de la planta están
asociados a niveles moderados de cianogénesis (Caradus y Williams 1989).
El polimorfismo es, sin duda, de origen genético; ahora
bien, aunque se investigó el mantenimiento de la variabilidad
de la cianogénesis y el papel de las fuerzas selectivas que
operan para que esto ocurra, el sistema no ha podido ser
entendido, en realidad. Si bien las relaciones entre latitud,
altitud y distribución de los genes ¾encontradas por Daday
(1954a; 1954b) y confirmadas por otros autores como Caradus
et al. (1990)¾ están bien establecidas, es decir, el porcentaje de
cianogénesis disminuye con el incremento de la altura y la
latitud, quedan sin resolver las relaciones entre otros factores
ambientales y biológicos que determinan el patrón de esa
distribución. Así pues, la cianogénesis se considera
generalmente como una protección contra los herbívoros
depredadores y contra los insectos perjudiciales. Si esta fuese
la única presión de selección, todas las poblaciones de trébol
blanco deberían ser cianogénicas. Ahora bien, muchas de esas
poblaciones no liberan HCN o son una mezcla de genotipos.
Algunos estudios demuestran que las formas acianogénicas
pueden ser favorecidas bajo ciertas condiciones edáficas
(Foulds y Grime 1972). Entre los estudios hechos para
determinar ventajas comparativas, Noitsakis y Jacquard
(1992), sugirieron que los fenotipos acianogénicos tienen
mayor acumulación de biomasa y producen más flores por
planta, lo que puede ser el resultado de una utilización más
eficiente de la energía; esas plantas tendrían, por tanto, mejor
comportamiento bajo la condición de pasturas polifíticas.
En relación con la variación en contenido, Daday (1955)
halló una correlación positiva entre las poblaciones que tenían
mayor proporción de plantas cianogénicas, de un lado, y una
reacción de picrato más intensa, del otro. Caradus et al. (1989)
encontraron que el alto potencial de liberación de HCN estaba
claramente asociado con cultivares en que es más frecuente el
fenotipo cianogénico.
Las poblaciones de trébol blanco son polimórficas en su
propiedad cianogénica; esta característica es, por tanto, útil
como marcador genético y ha sido considerada así en muchos
trabajos. Hawkins (1959), por ejemplo, la utilizó para la
clasificación e identificación de variedades de trébol blanco.
La lista mundial de variedades de trébol también incluye este
carácter en la descripción de éstas (Caradus 1986; Caradus y
Woodfield 1997). Es, además, uno de los descriptores
sugeridos por el IBPGR (1992) para el trébol blanco (Trifolium
repens L.).
Este estudio tenía los siguientes objetivos: (1) caracterizar
poblaciones introducidas y naturalizadas de trébol blanco del
banco de germoplasma de la EEA INTA Pergamino; (2)
determinar, en las poblaciones colectadas en Argentina, las
posibles asociaciones del polimorfismo cianogénico con
caracteres morfofisiológicos y con aspectos ecológicos, según el
sitio de recolección del material, y (3) considerar la utilización de
esa característica en la identificación o en la clasificación de las
accesiones argentinas de trébol blanco.
Materiales y métodos
Las 21 accesiones introducidas eran originarias de Costa Rica
(PI 193164), Italia (Simone, PI 195532, 217444, 233813, 291837,
291838), Irán (PI 260984, 326144, 381049), Australia (Waverly,
Haifa, PI 201214, 237926, 241460), Israel (PI 200372), Chile (PI
291826, 291827), Japón (Makibashiro) y Estados Unidos
(MSRedF, MSLM). Como testigo se utilizó la población mejorada
El Lucero MAG (Argentina).
Los 53 materiales naturalizados eran originarios de las
provincias de Buenos Aires (1,2 3, 21, 22, 23, 24, 34, 36, 37, 38,
39), Santa Fe (4, 5, 6, 7, 8, 9, 10, 11, 19, 20, 25, 26, 27, 28, 29, 30,
31, 32, 33, 40, 41, 42, 43, 49, 50, 51), Entre Ríos (12, 13, 14, 15, 16,
17, 18), Córdoba (52, 53), La Pampa (35), Chaco (46, 47, 48) y
Formosa (44, 45), que comprenden una franja situada entre los
26º y los 38º de latitud S y de los 58º a los 63º de longitud O.
Cada planta se analizó aplicando la prueba del papel de
picrato (Pusey 1966) a la tercera hoja expandida contada desde
el ápice en crecimiento activo. Se colocó igual cantidad de hojas
(un peso equivalente) en varios tubos de ensayo, se agregaron 2
gotas de agua y se maceraron las hojas. Se añadieron luego 2
gotas de tolueno y se colocó un tapón de goma en cada tubo; del
tapón pendía una tira de papel embebido en picrato de sodio. Se
incubaron los tubos en la estufa a 40 °C durante 2 horas y se
sometieron a observación. Cuando el resultado era positivo,
había un cambio en el color del papel: del amarillo viraba a un
tono que va del naranja suave al marrón. Las plantas que dan
reacción positiva son las Ac /Li y la intensidad de la reacción se
asocia con la cantidad de HCN liberado; se clasificaron, por
tanto, las plantas en tres grupos: de reacción leve (color naranja),
moderada (color rojizo) y alta (color marrón). Se evaluaron 20
plantas de cada material y se establecieron las proporciones de
cada tipo de reacción.
Para el análisis estadístico se utilizó el paquete SAS (SAS
1985). Se hizo un análisis de correlación del carácter estudiado
con las siguientes variables: grosor de los estolones, hábito de
crecimiento, largo y ancho del folíolo, largo del pecíolo y días a
floración. Asimismo, mediante el análisis de componentes
principales se determinó la influencia de este carácter en los
componentes principales.
Resultados y discusión
La Figura 1 presenta la caracterización de la cianogénesis en la
colección de accesiones introducidas. Los resultados de la
evaluación de las poblaciones introducidas mostraron que, en la
mayor parte de éstas, son poco frecuentes las plantas que tienen
los dos genes complementarios en estado dominante (fenotipos
cianogénicos). La tendencia que muestra el germoplasma
analizado puede relacionarse con su lugar de origen ya que las
introducciones provienen de regiones frías o de alta montaña.
Los resultados indican que las poblaciones de Costa Rica, Chile,
Estados Unidos, Italia, Irán y Japón presentan un rango de
fenotipos cianogénicos que va de 0% a 40%.
Las introducciones de Australia e Israel, por su parte,
presentaron mayor frecuencia de fenotipos cianogénicos
similares al germoplasma de Argentina; el porcentaje de
liberación de HCN de las plantas de cada accesión estaba entre
75% y 100%.
No se detectó ninguna asociación significativa del carácter
de cianogénesis con las variables morfológicas y fenólogicas
estudiadas. Sin embargo, según Daday (1965) y Caradus et al.
(1989), los fenotipos cianogénicos florecen más temprano y los
acianogénicos producen mayor número de inflorescencias. En
estudios previos realizados en la EEA INTA Pergamino, el cultivar Espanso, que es acianogénico, se comportó como de floración
tardía pero muy escasa (Pagano et al. 1998). La floración es un
carácter altamente dependiente del fotoperíodo y también de la
vernalización; además, nuestras condiciones pueden diferir de
las que predominan en las regiones de origen de las poblaciones
introducidas. Estos dos hechos podrían considerarse como
causa probable de la ausencia de asociación de los caracteres
estudiados en dichas poblaciones.
En el análisis de componentes principales, la cianogénesis
fue el carácter de mayor importancia para definir el segundo
componente principal; es, por tanto, de importancia en la
clasificación del germoplasma caracterizado.
Dado que la concentración del HCN liberado varía entre
poblaciones y entre plantas dentro de una población, los
fenotipos cianogénicos se clasificaron según su capacidad de
liberación de HCN (Fig. 2); se encontró así una población de
trébol blanco proveniente de Israel que tenía alto contenido de
cianógenos, en especial el cultivar Waverley cuya producción de
HCN es muy alta.
En la colección de poblaciones naturalizadas de diferentes
provincias argentinas se encontró una alta frecuencia de
fenotipos cianogénicos (Fig. 3); algo similar se observó en el
testigo, Lucero MAG, que es el cultivar más difundo en el país.
La excepción fueron dos accesiones en las que la frecuencia de
plantas que liberan HCN fue de 40%. Estas plantas
correspondieron a una población colectada en la localidad de
mayor altura (140 msnm) y a otra población colectada en una
latitud mayor (37ºS). Esto coincide con lo expresado por muchos
autores, ya que la frecuencia de los genotipos cianogénicos
Fig. 2. Clasificación del contenido cianogénico de las
poblaciones introducidas de trébol blanco.
Fig. 3. Caracterización de la cianogenésis en las poblaciones
naturalizadas de trébol blanco.
Fig.1. Caracterización de la cianogénesis en las poblaciones
introducidas de trébol blanco.
disminuye con la altitud y con la latitud (Daday 1954a, 1954b;
Ganders 1990; Caradus et al 1990). También en poblaciones de
Canadá (alta latitud), Fraser (1989) encontró que sólo una
minoría eran cianogénicos, variando el porcentaje del genotipo
Ac/Li del 1.7% al 35%.
Según Foulds y Grime (1972), la exposición a una severa
sequía causa la muerte de los fenotipos con el gen Ac. En esta
colecta se tomaron poblaciones provenientes de sitios que
estaban sometidos a una prolongada sequía pero no se observó
que la frecuencia de plantas acianogénicas en dichas poblaciones
fuera alta.
En cuanto a la correlación de la cianogénesis con los
caracteres morfológicos y fenológicos en las poblaciones
colectadas en Argentina, se encontró una asociación
44
significativa entre la cianogénesis y el número de días hasta el
50% de floración (r = 0.36). Esta asociación no se ajustaría a lo
que concluyen Caradus et al. (1989) quienes observaron, en una
clasificación de 109 cultivares, que la tendencia de los cultivares
altamente cianogénicos era la floración temprana pero con bajo
número de inflorescencias.
En los primeros trabajos hechos en Nueva Zelandia se
encontró que las poblaciones cianogénicas eran de folíolos
grandes, más productivas y más persistentes (Foy y Hyde 1937);
ésta es también la tendencia de los nuevos cultivares
neozelandeses, a excepción del cv. G. Kopu (Caradus et al. 1995).
En Estados Unidos, en cambio, tanto los cultivares utilizados,
que se clasificaron entre los de folíolo grande, como el
germoplasma colectado han mostrado ser predominantemente
acianogénicos (Crush y Caradus 1995; Pederson et al. 1996). En
cambio, en este trabajo, si bien se observó una alta frecuencia de
poblaciones de folíolos grandes, no se halló ninguna asociación
de la cianogénesis con el tamaño de la hoja (en las introducidas,
r = 0.20, ns; en las colectadas, r = 0.15, ns respecto al ancho del
folíolo).
Los resultados de clasificar sobre la base de la intensidad de
la reacción de las plantas cianogénicas, en las poblaciones
argentinas, tienden a presentar una liberación de HCN de baja a
moderada. Esta característica ubica esas plantas como un
germoplasma de interés, ya que una alta producción de HCN
puede llegar a ser tóxica para los rumiantes; en algunos países se
recomienda no emplear cultivares con ese carácter. Además, se
debe señalar que, de acuerdo con la bibliografía consultada, una
frecuencia alta de plantas que contienen los genes Ac-/Li(fenotipo cianogénico) y el modo de reacción intenso de ellas
están fuertemente correlacionados (Caradus et al. 1989).
Es necesario considerar que la presión de selección a que han
sido sometidas las poblaciones naturalizadas debería ser
diferente en los diversos sitios de colecta, en los que hay
diferentes condiciones no sólo de clima y suelo sino también del
entorno en que se halla cada población; éstas provienen, en
efecto, de banquinas, parques y potreros naturales sometidos a
distintas intensidades de pastoreo y allí han estado con
diferentes especies acompañantes. Según los resultados
obtenidos, esas situaciones no han tenido influencia en la
generación de poblaciones que contrasten en el polimorfismo de
la cianogenésis de esta colecta. Así pues, el predominio de los
fenotipos cianogénicos puede deberse, en gran parte, al papel
desempeñado por el macroambiente el cual, para el área
explorada, va de templado a templado cálido, principalmente.
Conclusiones
Las poblaciones introducidas se caracterizaron por la
variabilidad en sus propiedades cianogénicas. Se estableció, en
efecto, que en ellas hay una alta frecuencia de formas
acianogénicas que poenen en evidencia las características de su
lugar de origen.
Las poblaciones naturalizadas colectadas en la Argentina
fueron todas cianogénicas con valores que variaron del 40% al
100%. Los valores más bajos correspondieron a sitios de latitud
y altitud mayores. Las formas más frecuentes de reacción fueron
la liberación de HCN leve o moderada.
No pudo detectarse una asociación de la cianogénesis con
los sitios de recolección que eran afectados por largas sequías.
Las poblaciones naturalizadas parecen responder a las
condiciones ambientales del área de colecta.
No se halló tampoco asociación de la cianogénesis con
caracteres morfológicos relacionados con aspectos agronómicos;
sólo se determinó una correlación positiva con el número de días
a floración en los ecotipos colectados. Según el análisis de
componentes principales, la cianogénesis fue un carácter de
importancia para la clasificación del germoplasma
caracterizado.
Agradecimientos
Las autoras agradecen al Ing. Agr. Oscar Bertín por la crítica
revisión de este manuscrito y al Consejo Regional Buenos Aires
Norte por el apoyo financiero para la realización de la colecta de
accesiones.
Referencias
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of white clover cultivars in New Zealand. Agronomy Society
of New Zealand Special Publications, No. 11. Grassland Research and Practice Series 6:45-47.
Caradus, J.R. and D.R. Woodfield. 1997. World checklist of white
clover varieties. NZ J. Agric. Res. 40:115-206.
Caradus, J.R. 1986. World checklist of white clover varieties. NZ
J. Exp. Agric. 14:119-164.
Caradus, J.R., M.B. Forde, S. Wewala and A.C. MacKay. 1990.
Description and classification of a white clover (Trifolium
repens L.) germplasm collection from southwest Europe. NZ
J. Agric. Res. 33:367-375.
Caradus, J.R., A.C. MacKay, D.R. Woodfield, J. van den Bosch
and S. Wewala. 1989. Classification of a world collection of
white clover cultivars. Euphytica 42:183-196.
Caradus, J.R. and W. Williams. 1989. Breeding for legume persistence in New Zealand. Pp. 529-530 in Proceedings of a Trilateral Workshop, Hawai. American Society of Agronomy,
Madison, Wisconsin.
Corkill, L. 1942. Cyanogenesis in white clover (Trifolium repens
L.): The inheritance of cyanogenesis. NZ J. Sci. Technol.
8(23):178-193.
Crush, J. and J. Caradus. 1995. Cyanogenesis potential and
iodine concentration in white clover (Trifolium repens L.) cultivars. NZ J. Agric. Res. 38:309-316.
Daday, H. 1954a. Gene frequencies in wild populations of Trifolium repens L.; I: Distribution by latitude. Heredity 8:61-78.
Daday, H. 1954b. Gene frequencies in wild populations of Trifolium repens L.; II: Distribution by altitude. Heredity 8: 377384.
Daday, H. 1955. Cyanogenesis in strains of white clover. J. Brit.
Grassl. Soc. 10:266-274.
Daday, H. 1965. Gene frequencies in wild populations of Trifolium repens L.; IV: Mechanism of natural selection. Heredity
20:355-365.
Foulds, W. and J. Grime. 1972. The response of cyanogenic and
acyanogenic phenotypes of Trifolium repens to soil moisture
supply. Heredity 28:181-187.
Foy, N. and E. Hyde. 1937. Investigation of the reliable of the
“Picrit acid test” for distinguishing strains of white clover in
New Zealand. NZ J. Agric. 55:219-224.
Fraser, J. 1989. Characteristics of naturalized populations of
white clover (Trifolium repens L.) in Atlantic Canada. Can. J.
Bot. 67:2297-2301.
Ganders, F.R. 1990. Altitudinal clines for cyanogenesis in introduced populations of white clover near Vancouver, Canada.
Heredity 64:387-390.
Hawkins, R.P. 1959. Botanical characters for the classification
and identification of varieties of white clover. J. Nat. Inst.
Agric. Bot. 8:675-682.
Hughes, M.A. 1991. The cyanogenic polymorphism in Trifolium
repens L. (white clover). Heredity 66:105-115.
Hughes, M.A., J. Stirling and D. Collinge. 1984. The inheritance of
cyanoglucoside content in Trifolium repens L. Biochem. Genetics 22:139-151.
IBPGR (International Board for Plant Genetic Resources). 1992.
Descriptors for white clover (Trifolium repens L.). IBPGR,
Rome.
Lehmann, J., E. Meister, A. Gutzwiller, F. Jans, J. Charles and J.
Blum. 1991. Peut-on utiliser des varietés de trefle blanc (Trifolium repens L.) a forte teneur en acide cyanhydrique? Revue
Suisse Agricole 23(2):107-112.
Noitsakis, B. and P. Jacquard. 1992. Competition between cyanogenic and acyanogenic morphs of Trifolium repens. Theor.
Appl. Genet. 83:443-450.
Pagano, E.M., J.O. Scheneiter and P. Rimieri. Persistencia
vegetativa de trébol blanco (Trifolium repens L.) en el norte de
la Provincia de Buenos Aires. Rev. Tecnología Agropecuaria
3(7):15-18.
Pederson, G., T. Fairbrother and S. Greene. 1996. Cyanogenesis
and climatic relationships in U.S. white clover germplasm
collection and core subset. Crop Sci. 36:427-433.
Pusey, J.G. 1966. Cyanogenesis in Trifolium repens L. Pp. 99-104 in
Teaching Genetics (C.D. Darlington and A.D. Bradshaw,
eds.). R.U., Edinburgh y Londres.
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Cary, North Carolina, E.U.
46
ARTICLE
Conservation et valorisation des ressources
génétiques fourragères et pastorales du Nord Tunisien
M. Chakroun1* et M. Zouaghi2
Institut National de la Recherche Agronomique de Tunisie, Rue Hadi Karray, 2049, Ariana, Tunisie.
Fax : 216-1-752-897. Email: [email protected]
2 Institut National Agronomique de Tunis, 43 Avenue Charles Nicole, 1002, Tunis, Tunisie.
1
Résumé
Conservation et valorisation
des ressources génétiques
fourragères et pastorales du
Nord Tunisien
La Tunisie, à l’instar des pays du bassin
méditerranéen, possède une grande richesse d’espèces spontanées fourragères et
pastorales. Cependant, ces espèces naturelles sont restées, jusqu’à présent, peu
étudiées et sous-exploitées. Seules
quelques espèces fourragères spontanées et/ou cultivars traditionnels, ont
été évalués et ont fait l’objet de collections souvent actives. Mais, la plupart des
espèces n’ont pas encore franchi l’étape
de l’observation générale, bien qu’elles
aient déjà enrichi de nombreuses
banques de gènes internationales et servi
à développer de nombreux cultivars. De
nombreuses missions de prospection ont
permis la collecte de près de 2800 accessions appartenant à plus de 100 espèces.
Cet effort d’exploration et de collecte des
plantes autochtones fourragères et pastorales, déployé par l’ensemble des institutions d’enseignement et de recherche
en agriculture, est la première étape de la
mise en valeur des ressources génétiques
locales. La conservation et l’utilisation de
ces ressources phytogénétiques locales
constituent aujourd’hui l’un des programmes prioritaires adoptés par les
commissions de programmation de la
recherche agronomique dans le cadre des
actions de sauvegarde et de valorisation
du patrimoine génétique fourrager et
pastoral. Il repose sur l’évaluation, la
sélection et le développement de cultivars tunisiens en vue de leur introduction sur le marché et de leur utilisation
par les agriculteurs.
Resumen
Túnez, como cualquier otro país mediterráneo, dispone de una rica diversidad
genética en especies forrajeras y herbáceas, pero estas especies naturales no se
han estudiado ni se utilizan cabalmente.
Pocas de ellas son evaluadas y conservadas. Otras se estudian insuficientemente,
aunque se conservan en muchos bancos
de germoplasma internacionales y a
partir de ellas se han desarrollado diversos cultivares mejorados. Se han realizado numerosas misiones de exploración
que han permitido recoger unas 2800
accesiones correspondientes a más de
100 especies. Esta actividad de exploración, a cargo de investigadores de los
Institutos Nacionales de Investigación y
Educación, es sólo el primer paso para
desarrollar los recursos genéticos locales,
cuya conservación y uso constituyen uno
de los programas prioritarios adoptados
por los Comités Nacionales de Planificación de la Investigación para la conservación y valorización de los recursos forrajeros y herbáceos. Este programa se
proponía evaluar el material conservado
e incorporarlo a los programas de mejoramiento de forrajes y pastos, desarrollando así nuevos cultivares para su uso
por los agricultores.
Summary
Tunisia, like any other Mediterranean
country has been recognized as rich
source of genetic diversity for forage and
pasture species. However, these natural
species are no fully studied and used.
Few forage and pasture species are
evaluated and conserved. Others are inadequately studied while they were conserved in many international genebanks
and from which a range of improved
cultivars have been developed. Numerous exploration missions were carried
out and led to the collecting of around
2800 accessions representing more than
100 species. This exploration effort, deployed by researchers at the National
Research and Education Institutes, is only
the first step in the development of local
genetic resources. Today, the conservation and use of these local genetic resources constitute one of the priority
programmes adopted by National Research Planning Committees representing the preservation and valorization of
the forage and pasture resources. This
programme aimed to evaluate and incorporate the conserved material into
forage and pasture improvement
programmes and thus to develop new
cultivars that will be used by farmers.
Key words: Collecting, conservation,
evaluation, forage, genetic diversity,
genetic resources, improvement
programme, pasture, Tunisia
Introduction
La Tunisie présente une grande richesse d’espèces spontanées
fourragères et pastorales propres à l’alimentation animale mais
dont la valeur fourragère est mal connue. Déjà en 1911, GAGEY
rapportait l’existence dans de nombreuses régions, de plusieurs
espèces fourragères spontanées intéressantes appartenant aux
genres Medicago (espèces annuelles et pérennes), Scorpiurus
(vermiculatées), Lolium (rigidum), Trifolium (repens, hybridum,
subterraneum, fragiferum), Boromus, Lotus, Hedysarum, Phalaris, et
Dactylis qui servaient à alimenter les troupeaux (Lapeyronie 1978).
Malgré les efforts des chercheurs, ces ressources génétiques
fourragères et pastorales naturelles restèrent peu étudiées et
sont encore sous-exploitées. Seules quelques espèces fourragères
spontanées ou cultivars traditionnels, ont été évalués et ont fait
l’objet de collections souvent actives. Pour d’autres, seules des
observations générales ont été reportées, alors qu’elles ont servi à
enrichir de nombreuses banques de gènes internationales et à
développer de nombreux cultivars (Zouaghi 1989). Ainsi, le
Catalogue australien indique l’existence de très nombreux cultivars de graminées ou légumineuses (fétuque élevée, ray-grass
anglais, dactyle, phalaris, medics etc.) obtenus à la suite d’une
simple évaluation des ressources génétiques introduites à partir
de l’Afrique du Nord (Tunisie, Algérie, Libye et Maroc). La
plupart de ces cultivars sont utilisés de nos jours au sud de
l’Australie, particulièrement dans les régions où les
précipitations sont comprises entre 350 et 500 mm. C’est le cas
de la fétuque élevée ‘Déméter’, du dactyle ‘Currie’ ou de Medicago
truncatula ‘Jemalong’ (Oram 1991).
La conservation et la valorisation des ressources génétiques
fourragères et pastorales sont devenues urgentes. L’objet de
cette étude est de présenter une synthèse sur l’état des cultures
fourragères et des principales espèces pastorales, sur les institutions en charge de la conservation et de la valorisation des
ressources génétiques fourragères et pastorales en Tunisie,
l’inventaire des travaux de collecte et les menaces d’érosion
génétique. Une présentation des programmes en cours et de leur
organisation concluent ce rapport.
Cultures fourragères et principales
espèces pastorales
En Tunisie, le développement de l’élevage, secteur prioritaire de
production, repose en grande partie sur la disponibilité des
ressources alimentaires constituées d’une part, par les fourrages
cultivés, les résidus de récolte et les sous-produits agroindustriels (19% des besoins de l’ensemble des élevages), et
d’autre part, par les parcours, les arbustes fourragers et les zones
forestières (67-68% des besoins). Les aliments concentrés
représentent 13% du total des besoins alimentaires des
troupeaux. Parmi ces ressources, les fourrages et les parcours
occupent une superficie importante mais la contribution des
fourrages aux besoins du cheptel est faible et va en diminuant
en raison de l’utilisation abusive des parcours et de la réduction
des surfaces fourragères semées (Zouaghi 1998).
L’extension des cultures fourragères et pastorales prévue par
les plans de développement se concrétise difficilement et les
rendements de ces cultures restent faibles. Une analyse de
l’exploitation pastorale et des cultures fourragères pratiquées en
Tunisie, a permis de constater la faible productivité des couverts
végétaux des zones pastorales et le manque de diversité des
cultures fourragères. De plus l’insuffisance de semences
fourragères constitue encore un handicap à l’extension de ces
cultures.
Cultures fourragères
Le secteur fourrager est basé essentiellement sur la culture de
l’avoine pure (Avena sativa L.) et/ou de la vesce-avoine récoltée
sous forme de foin. La luzerne cultivée (Medicago sativa L.) et le
bersim (Trifolium alexandrinum) sont cultivés particulièrement
dans les périmètres irrigués et les oasis. En culture pluviale,
l’orge en vert (Hordeum vulgare) tend à se substituer à la vesceavoine dans les zones les plus arides ou plus salées. D’autres
cultures fourragères telles que le sulla (Hedysarum coronarium) sont
actuellement en cours d’extension avec plus ou moins de succès.
Le trèfle souterrain (T. subterraneum), les Medicago annuels (Medicago
spp.), malgré les programmes de développement dont ils ont fait
l’objet, sont en régression. Cet échec est imputable à l’application
d’un modèle de mise en valeur étranger (australien) qui a été
difficilement accepté par les agriculteurs. Dans les périmètres
irrigués, le ray-grass d’Italie (Lolium multiflorum) et les cultures
dérobées d’été comme le maïs (Zea mays L.) et le sorgho fourrager
(Sorghum sp.), sont en augmentation. Les cultures pérennes sont
de plus en plus pratiquées dans le nord du pays,
particulièrement le sulla. D’autres espèces telles que la fétuque
élevée (Festuca arundinacea) et le ray-grass anglais (Lolium perenne)
sont, pour l’instant, destinées uniquement à la création de
prairies permanentes.
Toutefois, la performance de ces cultures reste insuffisante, en
raison des facteurs suivants :
• la non-maîtrise des techniques d’installation, de conduite
des cultures, de récolte et de conservation
• l’inadaptation variétale des espèces les plus couramment
cultivées
• l’emploi de semences non certifiées concurrençant un secteur
semencier tunisien peu encouragé
• l’érosion et la perte de fertilité des sols aggravées par un travail
du sol effectué parfois perpendiculairement aux courbes de
niveaux.
Principales espèces pastorales herbacées
Les prairies du Nord ont été considérées, pendant longtemps,
comme le réservoir fourrager naturel de la Tunisie. Ces zones
naturelles ont été intensément défrichées au profit des cultures
céréalières, arboricoles et, plus récemment, de prairies
permanentes. Seule, la prairie à Hedysarum coronarium / Convolvulus tricolor située dans l’espace de la base aérienne de Bizerte
restent à l’état naturel. Le potentiel pastoral de ces zones demeure important comme le montre l’amélioration pastorale
réalisée à Sedjenane, où l’introduction d’espèces fourragères
productives telles que le trèfle souterrain, la fétuque élevée et le
ray-grass pérenne, a permis d’aménager 6 000 ha de prairies
dans le cadre du projet d’amélioration des pâturages dans le
nord-ouest tunisien (Jaritz 1982). Actuellement, les superficies
aménagées ne dépassent pas 8 000 ha. Ces prairies, malgré des
investissements importants, sont aujourd’hui fortement
dégradées en raison de l’inadéquation des systèmes
d’exploitation et de suivi. Elles sont à présent partiellement
couvertes d’une végétation inexploitable par les animaux qui
annonce le retour du maquis. D’autres prairies ont été converties
en céréaliculture et en arboriculture, zone à faible ressource
fourragère pour le cheptel.
La végétation naturelle non défrichée dans le nord, se répartit
sur trois types de pelouses (Thiault 1957; Lapeyronie 1982;
Zouaghi 1989, 1995) :
• la pelouse caractéristique des stations sèches sur sol à
encroûtement calcaire (Plantago lagopus et Echium parviflorum ou
Oryzopsis miliacea)
• la pelouse caractéristique des zones humides à inondation
passagère (Festuca elatior et Oenanthe globulosa)
• la pelouse sur marnes caractérisée par Hedysarum coronarium et
Convolvulus tricolor.
Ces trois catégories de pelouses comportent des espèces
pastorales dominantes susceptibles de régénérer des pâturages à
productivité satisfaisante.
L’augmentation des rendements passe par l’amélioration
des techniques culturales, le respect des stades de récolte et
l’utilisation des méthodes de conservation appropriées. Elle
dépend surtout de l’amélioration génétique et de la création de
variétés adaptées aux différentes conditions du milieu (sol,
48
climat, parasites et autres). La création variétale est assujettie
à la disponibilité en ressources génétiques locales intégrant les
adaptations aux conditions du milieu. Dès lors, la conservation et la valorisation des ressources génétiques deviennent
essentielles pour répondre aux besoins actuels et futurs du
pays.
Ressources génétiques fourragères et
pastorales
Institutions en charge de la conservation et de la
valorisation des ressources génétiques fourragères
et pastorales en Tunisie
Le maintien de la diversité et la réussite des programmes
d’amélioration de la productivité passent par la conservation et
la valorisation des ressources génétiques locales. Plusieurs institutions tunisiennes sont en charge de cette étape :
• l’institut National Agronomique de Tunisie (INAT)
• l’institut National de la Recherche Agronomique de Tunisie
(INRAT)
• l’ecole Supérieure d’Agriculture du Kef (ESA Kef)
• l’ecole Supérieure d’Agriculture de Mateur (ESA Mateur)
• l’institut des Régions Arides de Médenine (IRA)
• l’institut National de la Recherche Scientifique et
Technologique de Tunisie (INRST)
• la Faculté des Sciences de Tunis.
Les activités des trois derniers instituts, ne relèvant pas du
Ministère de l’Agriculture pour cette opération, ne font pas
l’objet de cette étude.
Inventaire des travaux
Depuis la fin des années 60, des activités de collecte, de conservation et de valorisation des germoplasmes fourrager et pastoral sont menées par l’INAT et l’INRAT. Ainsi, à la suite de
diverses prospections de graminées et de légumineuses
pérennes, des collections actives ont été réunies et des travaux
d’évaluation et de sélection ont abouti à des variétés-populations de fétuque élevée, de ray-grass anglais, de dactyle,
d’Oryzopsis, de phalaris et de trèfles. Ces variétés se sont révélées
supérieures aux matériels étrangers testés, en termes
d’adaptation, de productivité et de persistance (Chakroun et al.
1994). Les variétés de fétuque élevée sont maintenues en parcelles
isolées in situ à la station de Mornag pour la production de
semences. Cependant, le manque de moyens de conservation a
conduit à la perte de la plus grande partie du matériel collecté.
Seule la collection de l’INAT a pu assurer une certaine continuité
dans ses travaux.
En 1976 et 1984, L’IPGRI (International Plant Genetic Resources
Institute) a organisé, en collaboration avec certains Instituts
Nationaux de Recherche, deux missions de prospection qui ont
permis la collecte de plusieurs espèces de céréales, de
légumineuses alimentaires et de plantes fourragères. En 1980,
une autre mission, effectuée dans le cadre du Projet intégré
(OEP), a concerné quelques espèces de légumineuses des genres
Medicago, Hedysarum et Trifolium. Cette prospection a couvert le
nord et le centre du pays et 41 accessions de Medicago, représentant
12 espèces ont été collectées. Mais, le manque de coordination
entre les divers intervenants et l’insuffisance des moyens
humains, matériels et financiers ont empêché ces travaux
d’évaluation d’aboutir à des écotypes commerciaux.
A l’INRAT, le laboratoire des Productions Fourragères s’est
particulièrement intéressé, ces dernières années, à la collecte, la
conservation (Tableau 1) et l’évaluation des ressources
génétiques fourragères et pastorales. En 1992, lors d’une mission de prospection en collaboration avec l’Unité des Ressources
Génétiques (GRU) de l’ICARDA, 377 accessions, représentant
49 espèces et 12 genres de légumineuses pastorales, ont été
collectées dans le centre du pays sur 40 sites (Hassen et al. 1994).
En 1994, une autre mission, effectuée en collaboration avec le
GRU et le Centre for Legumes in Mediterranean Agriculture d’Australie
(CLIMA), a permis la collecte de 894 accessions d’espèces de
légumineuses fourragères et pastorales représentant 16 genres et
80 espèces. Ces collections sont stockées à l’INRAT (Zoghlami et
Hassen, comm. pers.). En juin 1994, conformément à la Convention pour la préservation du patrimoine génétique des principales
graminées pérennes fourragères et pastorales, signée par
l’Institution de la Recherche et de l’Enseignement Superieur
Agricoles (IRESA), le Victorian Department of Agriculture (Australie)
et l’USDA, une prospection de 10 jours sur 57 sites a été réalisée
en collaboration avec le Department of Agriculture (Australie) et le
USAID (USA). Des semences de 93 populations des espèces
suivantes ont été collectées : fétuque élevée (Festuca arundinacea,
Schreb.), ray-grass anglais (Lolium perenne L.), dactyle (Dactylis
glomerata, L.) et phalaris (Phalaris tuberosa L.) (Chakroun et al. 1995).
Une dernière prospection, effectuée en collaboration avec
l’ICARDA en mai 1995, a assuré la collecte de 44 accessions du
genre Hedysarum et de leur rhizobium sur 42 sites du nord et du
centre du pays. La collection de rhizobium est installée à
l’ICARDA. Une partie de l’ensemble du matériel collecté est en
cours d’évaluation multilocale conformément au descripteur
international et devrait aboutir à la sélection d’écotypes adaptés
aux conditions locales.
A l’INAT, des travaux sur les ressources génétiques sont
conduits depuis les années 60. Mais, en l’absence d’un accord
préalable sur le devenir du matériel biologique à collecter, la collaboration avec les organismes internationaux n’a pu se
concrétiser. Les collectes sont aujourd’hui organisées chaque
année pour couvrir systématiquement l’ensemble du territoire et
permettre la constitution d’une collection active évaluée à environ
1200 lots de semences appartenant à 103 espèces fourragères et
pastorales originaires de différentes régions du pays (Tableau 1).
Certaines de ces espèces considérées comme prioritaires sont
conservées au froid et à –18°C, après déshydratation. Cette technique, appliquée depuis 1981, donne de bons résultats ; des lots
collectés à cette époque ayant montré, en 1996, un excellent
maintien du pouvoir germinatif. Actuellement, les collectes sont
financées uniquement par les Programmes Nationaux
Mobilisateurs (PNM) de Recherche et concernent : Hedysarum
coronarium, H. carnosum, H. spinosissimum, Trifolium sp., Medicago spp.,
Lathyrus et Lupinus ainsi que d’autres espèces de graminées et en
particulier la fétuque élevée (en collaboration avec le Laboratoire
des Productions fourragères de l’INRAT). Pour ces espèces, des
variétés sont en cours de production particulièrement pour le sulla
(Hedysarum coronarium), et le bersim (Trifolium alexandrinum).
Tableau 1. Espèces et nombre d’accessions fourragères et pastorales des différentes collections
INRAT
INAT
Genre
Espèce
Accession
Medicago
Vicia
Trifolium
Lathyrus
Lupinus
Hedysarum
Anthyllis
Astragalus
Coronilla
Hippocrepis
Lotus
Melilotus
Scorpiurus
Tetragonolobus
Trigonella
Pisum
Festuca
Lolium
Dactylis
Phalaris
Avena
Hordeum
Agropyrum
Tricosecale
Oryzopsis
Bromus
Crucifères
Autres
Total
25
8
20
3
3
4
2
7
2
4
5
2
2
1
4
1
1
1
1
2
2
405
108
179
36
3
83
10
63
29
52
77
19
126
14
27
1
38
19
22
14
12
†
‡
§
1
3†
104
Espèce
ESA Kef
Accession
Espèce
Accession
15
6
14
4
4
3
110
40
130
80
35
231
12
4
3
64
10
12
2
6
3
10
4
8
1
2
5
1
2
2
1
30
25
65
8
10
16
150
5
2
3
13
3
3
2
4
2
6
1
30
2
2
4
32 ‡
103
10
10
50
105
1218
2§
44
2
159
1
4
1342
Ononus et Hymonocarpus
Glycine, autres légumineuses et graminées.
Lespediza et Sesbania.
A l’ESA Kef, le travail sur les ressources génétiques, a débuté
en 1993 avec l’établissement d’une collection basée sur l’échange
de germoplasmes (Ben Youness, comm. pers.). L’ESA Kef dispose actuellement de 159 accessions représentant 44 espèces de
légumineuses et de graminées (Tableau 1).
•
Menaces d’érosion génétique
Depuis plusieurs années, les observations consignées par les
collecteurs indiquent une érosion génétique du matériel naturel
local.
Lapeyronie (1978), résumant les travaux de Gagey (1911)
signale que la flore dans les principales zones fourragères de la
Tunisie était, au début du siècle, beaucoup plus variée que dans
les années soixante. Actuellement, il est facile de constater qu’elle
est encore beaucoup plus dégradée notamment dans la zone de
Mateur - Mabtouha - Bizerte. Cette situation est attribuée à :
• l’introduction de variétés européennes et américaines pour
l’amélioration des rendements, ce qui a contribué à la
dénaturation des variétés locales, particulièrement pour les
espèces allogames telles que le sulla ou certains trèfles
• la destruction de l’habitat naturel de nombreuses espèces,
menacées de disparition en raison du développement de
l’urbanisation et de l’utilisation des terres (drainage des
zones humides et construction de barrages)
•
•
la mécanisation intensive de l’agriculture et la réduction
des terres de parcours au profit des cultures céréalières et
arboricoles aggravées par les catastrophes naturelles dans
les écosystèmes fragiles (en particulier sous bioclimats
semi-aride et aride), comme ce fut le cas en Tunisie en
1969
l’utilisation intensive d’herbicides destructeurs de la flore
messicole et surtout le surpâturage
les inondations et l’érosion catastrophique de la couche
arable du sol qui est le réservoir naturel des semences in situ
(Zouaghi 1988).
Les rapports de missions de prospection (Burton 1981;
Graves 1985; Cunnigham 1994) ont mentionné que les
germoplasmes fourragers et pastoraux sont soumis à une érosion
génétique forte, due à une croissance démographique de la
population, à une augmentation des zones de culture et à une
dégradation rapide des terres provoquée par une utilisation
inappropriée des techniques culturales modernes.
La tâche actuelle est donc de préserver la variabilité génétique
de notre patrimoine fourrager et pastoral et de le valoriser en
assurant son intégration dans les programmes d’amélioration
des plantes pour l’intérêt immédiat de nos agriculteurs et pour
un développement durable.
50
Esquisse d’une stratégie pour le
développement et la valorisation du
patrimoine génétique fourrager et
pastoral
• Incorporation du matériel génétique évalué dans les
programmes d’amélioration afin de créer de nouveaux cultivars
de plantes fourragères et pastorales.
La conservation et l’utilisation des ressources génétiques
fourragères et pastorales est l’un des programmes prioritaires
définis par les commissions de programmation de la recherche
(«Grandes Cultures» et «Elevage et Pastoralisme»). Dans ce
cadre, un programme a été développé par les laboratoires de
production fourragère de l’INRAT, l’INAT, l’ESA Kef et l’ESA
Mateur. Ce programme entre dans l’action «Sauvegarde et
valorisation du patrimoine génétique fourrager et pastoral» et
comprend deux thèmes : i) développement de germoplasmes
adaptés de légumineuses fourragères et pastorales ; ii) évaluation
et développement de quelques variétés-populations de
graminées pérennes fourragères et pastorales.
La flore naturelle de Tunisie, extrêmement riche en espèces
spontanées propres à l’alimentation animale, est en train de subir
une dégradation alarmante. La grande variation des conditions
du milieu (sol, température, pluviosité, humidité etc.…) a entraîné
l’existence, pour chaque espèce comestible, d’un grand nombre
d’écotypes. Cette variabilité génétique constitue un matériel de
choix pour la sélection et la création de variétés adaptées aux
conditions diverses. Parmi toutes ces espèces, une dizaine doit
retenir plus particulièrement l’attention en raison de leur large
utilisation actuelle, de leur potentiel élevé de production, et de leur
importance économique dans les zones humides, sub-humides et
semi-arides supérieures (Zouaghi 1987).
Les activités de conservation et de valorisation du patrimoine
fourrager et pastoral local intéressent deux types d’espèces
prioritaires : les légumineuses (et leur rhizobium), et les
graminées. Parmi les légumineuses, on s’intéressera en
particulier aux espèces Hedysarum, Vicia, Trifolium, Lupinus,
Medicago et Lotus. Concernant les graminées, les espèces
prioritaires sont : Avena sp., Festuca sp., Lolium perenne, Dactylis
glomerata, et Phalaris sp. Les espèces Phalaris sp., Vicia, Trifolium
fragiferum et Lupinus sont les plus menacées de disparition. Pratiques de terrain, moyens de conservation ex situ et techniques de
laboratoire seront optimisés pour aboutir à des créations
variétales susceptibles d’intéresser les agriculteurs.
Les espèces retenues pour les travaux d’amélioration sont :
• légumineuses fourragères : vesce, sulla, bersim et luzerne
cultivée
• légumineuses pastorales à resemis naturel (légumineuses
annuelles) : trèfle (Trifolium subterrameum), lupin et médics
(Medicago spp.)
• graminées annuelles et pérennes : avoine, orge en vert,
fétuque élevée, ray-grass pérenne, ray-grass annuel, Sudan grass
et maïs fourrager.
Plan d’action
fourragères et pastorales sont assurées par l’INAT, l’INRAT,
l’ESA Kef, l’IRA Médenine et, à un moindre degré, par l’ESA
Mateur. Pour pallier le manque de coordination des travaux,
effectués par des scientifiques de spécialités diverses, l’Equipe
de recherche fourragère et pastorale, regroupant tous les
chercheurs de la discipline, a instauré un accord de coordination
volontaire (Réunion de Mateur 1994). Les moyens humains et
matériels restent cependant insuffisants, avec une répartition
irrégulière des compétences suivant les instituts et une pénurie
en personnel de soutien. Néanmoins, une amélioration est en
cours depuis l’inscription des recherches fourragères au premier
plan des préoccupations officielles par le Conseil ministériel
restreint de mars 1998. Les structures existantes devraient encourager les chercheurs de ce groupe à resserrer les liens entre les
institutions responsables de la recherche et de la conservation
des ressources phytogénétiques fourragères et pastorales.
L’ampleur des travaux a amené l’Equipe de recherche à
procéder à la répartition des thèmes prioritaires de recherche et à
se préoccuper de la réactivation du fonctionnement des contrats
programmes.
Trois équipes de chercheurs, seront mises sur pied, chacune
spécialisée dans un type d’espèces : légumineuses fourragères,
légumineuses pastorales et graminées fourragères et pastorales.
En outre, ces équipes s’intéresseront, progressivement et en
fonction des financements, à la conservation et la valorisation
d’espèces locales non prioritaires.
Les missions de collecte seront planifiées en 5 phases :
1. Développement d’une stratégie de collecte et de l’itinéraire à
suivre.
2. Collecte : moyens de déplacement, fiche d’information.
3. Conditionnement et conservation du matériel collecté.
4. Constitution d’une base de données reliant les différentes
équipes à travers le réseau ‘intranet’ créé à l’IRESA.
5. Mise à disposition du matériel maintenu auprès des
utilisateurs potentiels (sélectionneurs, physiologistes, autres
banques de gènes...).
Objectifs du programme
• Poursuite des travaux de collecte des espèces fourragères et
pastorales spontanées pour le maintien de la diversité génétique
• Evaluation agronomique et fourragère du matériel biologique
collecté et multiplication en absence de contamination pollinique
• Conservation, à moyen et long terme, du matériel génétique
à des fins d’amélioration variétale
La réalisation des objectifs avancés dans ce programme de
conservation et de valorisation des ressources génétiques
fourragères et pastorales est subordonnée à la mise en application des étapes représentées dans la figure 1 et à l’obtention des
moyens humains, matériels et financiers nécessaires.
entre dans le cadre d’un travail pluridisciplinaire. L’ouverture
de cette activité à d’autres domaines dépendra des objectifs et de
l’importance économique du programme en question.
L’exploration et la collecte des plantes autochtones fourragères
et pastorales est le préalable au développement de ces ressources
génétiques qui verra son aboutissement dans le développement de
cultivars tunisiens commerciaux après évaluation et sélection.
L’exploitation efficace de ces ressources génétiques exige une
concertation et une coopération entre les différentes institutions, renforcées par des moyens de travail supplémentaires et
déjà initiées au sein de l’Equipe de Recherche Fourragère et
Pastorale créée en 1994 à la réunion de Mateur.
Remerciements
Les auteurs tiennent à remercier Mme Ghrabi Ghammar Z.,
Melle Zoghlami A. et MM. Hassen H., Ben Youness M., et Ben
Jeddi F. pour leur collaboration à la réalisation de ce travail.
Références
Anonyme. 1994. Orientations et programmes de recherche en
production fourragère en Tunisie. Mateur, 16-17 mars 1994.
Burton, J.C. 1981. Use of Rhizobium-leguminous plant association to increase forage and pasture production in Tunisia.
Report on a survey and nodule collection trip through Tunisia. 27 March-21 April 1981.
Chakroun, M., M.Y. Mezni et H. Seklani. 1994. Importance des
graminées pérennes locales dans la diversification des productions fourragères. Journées nationales sur les acquis
récents de la recherche agronomique. Hammamet, 2-4 déc
1994.
Chakroun, M., M.Y. Mezni, P. Cunningham and W. Graves. 1995.
Genetic resources collection of perennial pasture grasses in
Tunisia. «Options Mediterranéennes», Proceedings of the
meeting of the Mediterranian Working Group of the FAO/
CIHEAM Inter-Regional Research and Development Network
on Pastures and Fodder Crops, Avignon (France), 29 May-2
June 1995.49-51.
Hassen, H., A. Zoghlami et S. Sassi. 1994. Contribution à l’étude
de quelques espèces spontanées de légumineuses pastorales
en Tunisie centrale: Répartition géographique et relation avec
le milieu environnement. Ann. de l’INRAT, 67 (1,2): 203-221.
Jaritz, G. 1982. Amélioration des herbages et cultures fourragères
dans le nord-ouest de la Tunisie : étude particulière des
prairies de trèfles-graminées avec trifolium subterraneum. GTZ.
Germany.
Lapeyronie, A. 1982. Les productions fourragères
mediterranéennes. Tome I: Généralités, caractères botaniques
et biologiques. Techniques agricoles et productions
méditerranéennes. G.P. Maisonneuve et Larose, Paris, France.
McWilliams, J.L. 1980. Report on plant exploration and collection
in Tunisia. May/June 1980.
Oram, R.N. 1991. Register of Australian Herbage Plant Cultivars.
3 rd Edition. Australian Herbage Plant Registration Authority. Division of Plant Industry. CSIRO Publications,
Melbourne, Australia.
Thiault, M. 1957. Les pelouses de la Tunisie du Nord et leurs
aptitudes pastorales. Ann. du Ser. Bot. et Agr. de Tunisie. 30:
165-170.
Zouaghi, M. 1987. Production fourragère et pastorale en Tunisie.
Identification des problèmes et besoins de recherche à long
terme par grand secteurs de production. Programme de
développement de la recherche agricole en Tunisie. Vol. 2:
194-227. ISNAR R27f.
Zouaghi, M. 1989. Le patrimoine génétique fourrager et pastoral:
ressources à préserver et à promouvoir. Pp. 107-115 in Constitution de Réseaux Thématiques de Recherche Agricole au
Maghreb. Birouk, A., Ouhsine A. et Ameziane E. Eds, Actes
du séminaire organisé à Rabat en décembre 1988, Réseau
TRAM. ACCT.
Zouaghi, M. 1995. Etude et aménagement à prévoir dans la zone
des marais de l’Ichkeul. Rapport BCEOM sur l’aménagement
du Parc National de l’Ichkeul.
Fig. 1. Représentation schématique des principales activités liées à la conservation des ressources génétiques fourragères et pastorales.
52
ARTICLE
Resistance to powdery mildew in barley (Hordeum
vulgare L.) landraces from Egypt
Jerzy H. Czembor
Plant Breeding and Genetics Department, Plant Breeding and Acclimatization Institute, Radzików-Warsaw, 05-870 Blonie,
Poland. Tel: +48 22 7252611; Fax: +48 22 7254714; Email: [email protected]
Summary
Resistance to powdery mildew
in barley (Hordeum vulgare L.)
landraces from Egypt
This study consisted of screening 135 barley landraces collected in Egypt for resistance to powdery mildew. The landraces
originated from the collection of the International Center for Agricultural Research in the Dry Areas (ICARDA). Eight
landraces (6%) showed powdery mildew
resistance reactions and 11 single plant
lines were selected. Three of these lines
were tested in seedling stage with 17 differential isolates of powdery mildew and
another eight lines with 23 differential
isolates of powdery mildew. The isolates
were chosen according to their virulence
spectra observed on the Pallas isolines
differential set. Distribution of reaction
type indicated that 80% of all infection
types observed could be classified as
powdery mildew resistance (scores 0, 1
and 2). Line 441-1-1 showed resistance to
all major powdery mildew virulence
genes present in Europe. In nine lines
(82%) the presence of unknown genes in
combination with a specific one was detected. Two different resistance alleles
Mlat and Mla7 were postulated to be
present in the tested lines. The most common resistance allele in the tested lines
was Mlat, which was present in nine
tested lines. Among the three regions of
Egypt from which the landraces originated those collected in Marsa Matrruh
and north Sinai expressed resistance to
powdery mildew. All landraces collected
in As Sahra Ash Sharqiyah were susceptible to R303 isolate. The barley landraces
discussed in this study will be of value in
diversifying the genes resistant to powdery mildew used in barley breeding.
Key words: Erysiphe graminis,
germplasm, Hordeum vulgare,
landraces, powdery mildew, resistance genes
Résumé
Résistance au blanc des races
locales d’orge (Hordeum
vulgare L.) provenant d’Egypte
Cette étude a consisté à cribler 135 races
locales d’orge collectées en Egypte en
vue de tester leur résistance au blanc. Ces
races locales provenaient de la collection
du Centre international pour la recherche agricole dans les régions sèches
(ICARDA). Huit variétés locales (6 %) ont
résisté au blanc et 11 lignées dérivant
d’une plante unique ont été sélectionnées. Trois de ces lignées ont été testées
au stade plantule par 17 isolats différenciés de blanc et huit autres lignées par 23
isolats différenciés de blanc. Les isolats
ont été choisis selon leur spectre de virulence observé sur la série différenciée
d’iso-lignées de Pallas. La distribution du
type de réaction indique que 80 % des
types d’infection observés pouvaient
être classés comme résistants au blanc
(cotes: 0, 1 et 2). La lignée 441-1-1 a affiché
une résistance à tous les principaux gènes
de virulence du blanc présents en Europe. Chez neuf lignées (82%), on a détecté la présence de gènes inconnus associés à un gène spécifique. On a posé comme principe que deux différents allèles
de résistance Mlat et Mla7 étaient
présents chez les lignées testées. L’allèle
de résistance le plus fréquent chez les
lignées testées était Mlat, présent chez
neuf lignées testées. Sur les trois régions
d’Egypte d’où provenaient les variétés
locales, celles récoltées à Marsa Matrruh
et dans le nord du Sinaï se sont montrées
résistantes au blanc. Toutes les races locales récoltées à As Sahra Ash Sharqiyah
étaient sensibles à l’isolat R303. Les races
locales d’orge examinées dans cette
étude seront précieuses pour la diversification des gènes résistants au blanc utilisés dans les programmes d’amélioration
de l’orge.
Resumen
Resistencia al mildiu
pulverulento en las variedades
locales egipcias de cebada
(Hordeum vulgare L.)
Este estudio consistió en seleccionar 135
variedades de cebada recogidas en Egipto para observar su resistencia al mildiu
pulverulento. Las variedades procedían
de la colección del Centro Internacional
de Investigaciones Agronómicas en Zonas Áridas (ICARDA). Ocho de ellas (6%)
tuvieron reacciones de resistencia al mildiu y se seleccionaron 11 líneas de plantas
separadas. Tres de éstas se sometieron a
prueba en su fase de plántulas con 17
cultivos aislados diferenciales de mildiu,
y otras ocho líneas se sometieron a la
misma prueba con 23 aislados diferenciales de mildiu. Los cultivos aislados se
escogieron por sus espectros de virulencia observados en la serie diferencial de
isolíneas Pallas. Los tipos de reacción indicaron que el 80% de todas las infecciones observadas podían clasificarse
como resistencia al mildiu pulverulento
(0, 1 y 2 puntos). La línea 441-1-1 mostró
resistencia a todos los principales genes
de virulencia de mildiu presentes en Europa. En nueve líneas (82%) se detectó la
presencia de genes desconocidos en combinación con uno específico. Se dedujo la
presencia en las líneas sometidas a prueba de dos alelos de resistencia diferentes
Mlat y Mla7. El alelo de resistencia más
común en esas líneas era Mlat, presente
en nueve líneas. Entre las tres regiones
de Egipto de las que procedían las variedades locales, las recogidas en Marsa
Matrruh y Sinaí septentrional mostraron
resistencia al mildiu pulverulento. Todas
las variedades recogidas en As Sahra Ash
Sharqiyah eran susceptibles al aislado
R303. Las variedades de cebada aquí estudiadas serán valiosas para diversificar los
genes resistentes al mildiu utilizados en
la mejora genética de la cebada.
Introduction
Barley (Hordeum vulgare L.) is the fourth most important cereal crop
in the world after wheat, maize and rice. Among African countries,
barley is an important crop in Ethiopia, Eritrea and Sudan, and in
North African countries such as Morocco, Tunisia, Algeria, Libya
and Egypt (Rasmusson 1985; Czembor and Czembor 2000).
Powdery mildew, caused by the pathogen Erysiphe graminis
DC. f. sp. hordei Em Marchal (synamorph Blumeria graminis (DC.)
Golovin ex Speer f. sp. hordei), is one of the most destructive
foliar diseases of barley in areas with a maritime climate such as
northern Europe, Japan and the Mediterranean coast. In recent
years, this disease has also become more significant in areas
with a dry and hot climate because of the increased use of
irrigation and nitrogen fertilizer. Losses in barley yields due to
powdery mildew can reach 20% in Europe and 30% in North
Africa (Scott and Griffiths 1980; Rasmusson 1985; Zine
Elabidine et al. 1992; Czembor and Czembor 1998, 1999b).
Egypt is located in an area where different phytogeographical regions meet. The deserts of Egypt have widely different
ecosystems. Marsa Matrruh province in western Egypt is characterized by deep depressions reaching more than 100 m below
sea level, such as the Qattara depression and the oases. On the
other hand, high mountains rising more than 2100 m asl occur
in Sinai and in the As Sahra Ash Sharqiyah (eastern desert).
Rain-fed agriculture prevails in the northwest coastal strip from
Alexandria to the Libyan border and in north Sinai, with average annual precipitation of 100-250 mm. In these regions barley
is still grown as landraces, both for grain and straw, in marginal
low-input drought-stressed environments. The importance of
barley landraces in these areas is due to the fact that they are
often the only possible rain-fed crop (AboElenein et al. 1995;
Batanouny 1995; Madkour and Abou-Zeid 1995; FAO 1996).
In Europe during the 19th century, a few farmers and landowners such as Knight in England, Janasz in Poland, Vilmorin in
France and Rimpau in Germany started to select desirable plants
from landraces, based upon their phenotypic variation (Janasz
1893; Jensen 1988; Zeven 1996, 1998). Often only one line was
selected as a new cultivar and the landrace from which this line
was selected was no longer maintained. This has resulted in a
great deal of genetic erosion of major crops during the last 100
years. In most European countries today landraces of major
crops, including barley, exist only in genebanks (Brush 1992; Zine
Elabidine et al. 1995; Hammer et al. 1996; Podyma 1997).
Genetic studies of barley resistance to powdery mildew started
in 1907 when Biffen showed that the resistance of Hordeum
spontaneum is controlled by a single recessive gene. Currently powdery mildew on barley is considered as one of the most clearly
characterized system of host-pathogen genetic interaction and
more than 100 barley powdery mildew resistance alleles have been
identified. Most of these genes originated from barley landraces
from West Asia, Ethiopia and North Africa (Biffen 1907; Czembor
1976; Jensen and Jørgensen 1991; Jørgensen 1992b, 1994).
Powdery mildew on barley can be controlled by the use of
fungicides and/or resistant cultivars. About 20 years ago fungicide treatment against E. graminis f. sp. hordei became a common
practice in order to reduce the severity of powdery mildew.
However, pathotypes of E. graminis f. sp. hordei resistant to commonly used fungicides have now been identified. This, together
with the cost of fungicides and environmental concerns regarding pesticide use in most developed countries, may lead to a
gradual limitation of their use for control of powdery mildew
(Gacek 1992; Brown and Kane 1994; Brown 1996).
Breeding for resistance is a cheap and environmentally safe
alternative approach to reduce the loss in yields caused by
powdery mildew. However, breeding for resistance depends
upon having genepools from which new genes can be introduced into existing cultivars. Such genepools are barley
landraces, especially those originating from centres of origin for
cultivated barley (Ceccarelli et al. 1987, 1995; Valkoun et al. 1995;
ICARDA 1998; IPGRI 1999).
The original area of cultivation of Hordeum vulgare L. was the
Fertile Crescent (a crescent-shaped region of rich farmland that
stretched in ancient times from the Mediterranean sea to the
Persian Gulf, through the Tigris and Euphrates valley) and Egypt
(Zohary and Hopf 1988; Nesbitt 1995; Willcox 1995). According
to archaeological evidence barley was cultivated in this region in
the ninth millennium B.C. (Wendorf et al. 1979, 1984; Williams
1988, 1995; Harlan 1995; Damania and Valkoun 1997).
Vavilov (1926) believed the Mediterranean area to be one of
the major centres of the crop’s origin. Recently, this hypothesis
has been supported by the discovery of wild barley in North
Africa (Molina-Cano and Conde 1980; Molina-Cano et al. 1982,
1984, 1999; Moralejo et al. 1994). This would suggest that in this
region barley coevolved with the fungus E. graminis f. sp. hordei,
therefore, barley landraces from Egypt may possess new genes
for resistance to powdery mildew. The objective of this study
was to determine whether genes resistant to powdery mildew
are present in Egyptian landraces of barley.
Plant material
Drs J. Valkoun and S. Ceccarelli of ICARDA kindly provided
seed samples of 135 Hordeum vulgare L. landraces. The seeds of
124 landraces were collected in three regions from 15-25 April
1987 (ICARDA collection code EGY87) and seeds of a further 11
landraces were collected from 18-20 April 1989 (ICARDA collection code EGY89). Of these, 79 landraces (58.5%) originated
from Marsa Matrruh (Mediterranean coast, Libyan plateau,
Qattara Depression and the Siwa Oasis), 47 (35%) originated
from north Sinai and nine (6.5%) from As Sahra Ash Sharqiyah
(eastern desert). All collected barley landraces were of a springgrowth type, had covered kernels and six-row heads. In Polish
conditions they were intermediate in heading date and showed
low resistance to lodging.
Pathogens
Thirty-five isolates of E. graminis f. sp. hordei Em Marschal were
used (Table 1). These originated from collections in the Risø
National Laboratory, Denmark; the Danish Institute for Plant
and Soil Science, Denmark; the Edigenossische Technische
Hochschule (ETH), Switzerland, kindly provided by Dr H.J.
Schaerer; and from the Plant Breeding and Acclimatization
Institute (IHAR) Radzików, Poland. The isolates were chosen
according to differences in virulence spectra observed on the
Pallas isolines differential set (Kølster et al. 1986) provided by Dr
L. Munk (Royal Agricultural and Veterinary University, Denmark). They were purified by single pustule isolation, and maintained and propagated on young seedlings of the powdery
mildew susceptible cultivar ‘Manchuria’ (CI 2330). Frequent
virulence checks were made to assure the purity of isolates
throughout the experiment.
Disease assessment
After 8-10 days incubation, the infection types were scored
according to a 0-4 scale developed by Mains and Dietz (1930).
The seedlings were classified into susceptible or resistant groups.
Plants scoring 0-2 were included in the resistant group and
plants scoring 3-4 were included in the susceptible group.
Resistance tests
This investigation was conducted during 1996-99 at IHAR
P22
P23
P24
P12
P13
P14
P15
P17
P18
P19
P20
P21
P10
P11
P8B
P9
P8A
P7
P4B
P6
P4A
0(4)
2
4
4
2
4
3
4
4
2
2
4
0
4
4
4
4
4
4
4
4
4
0
1
0
0(4)
4
4
4
4
4
4
4
4
0
0
4
0
2
4
4
4
4
4
4
4
4
4
0
0
0(4)
4
4
4
1
4
4
4
4
2
2
4
0
0
0
4
0
0
4
4
4
4
0
0
0
0(4)
4
4
0
1
4
4
4
4
2
2
4
4
4
4
4
4
4
4
4
4
4
4
0
0
0(4)
3
0
4
1
0
4
0
4
2
4
0
0
0
0
0
0
0
1
0
0
4
4
0
0
A6
0(4)
2
4
4
1
4
2
2
4
2
2
0
0
0
0
0
0
0
1
0
2
4
4
0
0
D17
0(4)
3
4
4
1
4
4
2
4
2
2
0
4
0
0
4
0
0
0
0
0
4
4
0
0
EmA30
0(4)
2
4
4
1
4
2
2
4
2
2
4
0
0
0
0
0
0
0
1
0
4
0
0
4
GE
3
2
0
4
2
4
2
2
4
1
2
4
0
0
0
0
0
0
2
2
2
4
0
0
4
HL3/5
3
3
4
4
1
4
4
0
4
2
2
4
0
0
0
0
0
0
2
0
0
4
0
0
4
0(4)
3
4
0
2
4
2
4
4
2
4
0
0
0
4
4
4
4
4
4
4
4
0
0
0
HL3/5-1 JEH11
11
0(4)
2
4
4
2
0
2
0
3
2
2
4
2
4
0
0
0
0
4
4
2
4
0
0
4
MH1
12
0(4)
4
4
4
1
0
0
2
4
2
2
4
4
4
0
0
0
0
4
4
2
4
0
0
0
MH1-2
13
0(4)
3
4
4
2
4
4
2
4
2
2
0
4
0
0
1
0
0
2
2
2
4
0
0
4
R13C
14
0(4)
4
4
4
1
4
4
2
4
2
2
0
4
4
0
2
0
0
4
4
4
4
0
0
4
R63
15
0(4)
4
4
0
2
4
4
2
4
2
2
0
4
0
0
4
0
0
2
1
1
4
0
0
0
R71/1
16
0(4)
4
4
4
2
4
2
2
4
2
2
0
0
0
0
0
0
0
2
2
2
4
0
0
4
R86.1
17
Mla8
Mla1
Mla3
Mla6,
Mla14
Mla7,
Mlk,?
Mla7,?
Mla7,
Ml(LG2)
Mla9,
Mlk
Mla9,
Mlk
Mla9
Mla10,
Ml(Du2)
Mla12
Mla13,
Ml(Ru3)
Mla22
Mla23
Mlra
Ml(Ru2)
Mlk
Mlnn
Mlp
Mlat
Mlg,
Ml(CP)
mlo5
Ml(La)
Mlh
63-1
10
Pallas
P1
P2
P3
59-12
9
59-11
8
58-74
7
1
Gene
Isolines
6
2
Isolates
Differential set
5
Table 1. Differential isolates and their infection types on Pallas differential sets
4
3
54
P22
P23
P24
P12
P13
P14
P15
P17
P18
P19
P20
P21
P10
P11
P8B
P9
P8A
P7
P4B
P6
P4A
Pallas
P1
P2
P3
Mla8
Mla1
Mla3
Mla6,
Mla14
Mla7,
Mlk,?
Mla7,?
Mla7,
Ml(LG2)
Mla9,
Mlk
Mla9,
Mlk
Mla9
Mla10,
Ml(Du2)
Mla12
Mla13,
Ml(Ru3)
Mla22
Mla23
Mlra
Ml(Ru2)
Mlk
Mlnn
Mlp
Mlat
Mlg,
Ml(CP)
mlo5
Ml(La)
Mlh
18
Isolines Gene
20
0(4)
2
4
4
1
4
2
2
4
2
2
0
0
0
4
0
1
1
2
0
2
4
0
4
4
0(4)
2
4
0
2
4
4
4
3
2
4
4
0
0
4
4
4
4
4
4
4
4
0
0
0
0(4)
3
4
0
2
4
2
4
4
2
2
4
0
4
4
4
4
4
0
0
0
4
0
0
0
R189 R261 R275
19
Isolates
Differential set
0(4)
3
3
0
1
3
2
0
0
0
0
3
0
0
0
4
0
0
0
0
0
4
0
0
0
R303
21
0(4)
4
4
4
1
4
2
1
4
2
2
4
0
0
0
0
0
0
0
0
0
4
0
0
4
Ru3
22
0(4)
4
4
4
2
4
2
4
4
2
2
4
4
0
4
4
4
4
2
1
2
4
4
4
0
TR2
23
0(4)
4
0
0
2
4
2
2
4
2
2
4
4
0
0
4
0
0
2
0
2
4
0
0
0
Ry4d
24
0(4)
4
4
4
1
4
4
4
4
2
2
4
4
4
0
4
0
0
4
4
4
4
0
0
0
En1/A1
25
0(4)
4
4
0
1
4
4
2
4
2
2
4
0
0
0
0
0
0
0
0
0
4
0
0
0
R303.1
26
0(4)
4
0
0
2
4
4
4
4
2
2
4
4
0
0
4
0
0
4
4
4
4
4
0
4
E92
27
0(4)
2
4
4
2
4
4
4
4
2
2
4
0
0
0
4
0
0
4
4
4
4
0
0
0
59-11.1
28
0(4)
4
4
4
2
4
4
0
0
2
4
4
4
0
0
0
0
0
2
0
2
4
0
4
4
SZ/C10
29
0(4)
4
4
4
2
4
4
2
4
2
2
0
0
0
0
0
0
0
0
0
0
4
0
0
4
Ra7
30
0(4)
4
4
0
2
4
4
4
4
2
2
4
4
0
0
4
0
0
4
2
4
4
0
4
4
Ra9
31
33
34
0(4)
4
4
4
2
4
4
4
4
2
4
4
4
4
0
4
0
0
4
1
4
4
4
0
4
0(4)
4
4
4
1
4
4
4
4
4
4
4
4
4
0
4
0
0
4
2
4
4
4
0
4
0(4)
4
4
0
1
4
4
4
4
2
2
4
2
0
4
4
4
4
4
4
4
4
0
0
4
Ra10 Ra13 Ra16
32
0(4)
4
4
0
2
4
4
4
2
0
2
4
4
4
0
4
0
0
4
4
4
4
0
0
4
Ra22
35
56
Radzików, Poland. In the winter of 1996-97 approximately 30
plants per landrace were evaluated in a greenhouse with the
R303 isolate of E. graminis f. sp. hordei. R303 represented the most
avirulent isolate available, allowing the expression of a maximum number of resistance genes. The cultivar ‘Manchuria’ was
used as a susceptible control. In addition, approximately 30
plants per landrace were evaluated in a greenhouse with a
mixture of E. graminis f. sp. hordei isolates with all the virulences
known in Europe. Again the cultivar ‘Manchuria’ was used as a
susceptible control.
Eight (6%) of the 135 landraces showed resistance reactions
(Table 2). From one to five resistant plants for each landrace were
grown in the greenhouse to obtain seed. In this manner, 11 single
plant lines were created. Three of these lines were tested with 17
isolates of powdery mildew during the winter of 1997-98 (Table
3). Another eight lines were tested with 23 isolates during the
winter of 1998-99 (Table 4). This research was conducted in the
IHAR Radzików greenhouse. The plants were grown with 16 h
light and a temperature range of 16-22oC. Inoculation was carried
out when the plants were 10–12 days old by shaking or brushing
conidia from diseased plants. The disease reaction types shown
by seedlings were scored after 8-10 days incubation.
Eleven single plant lines were selected. All these lines possessed one or more resistance alleles to powdery mildew of
barley (Tables 3, 4). However, only one line (441-1-1) expressed
resistance to all isolates used. It was impossible to determine
which specific gene or genes for resistance are present in line
441-1-1 (Table 4). Based on the assumption that different resistance genes may condition different infection types it may be
concluded that this line had more than one resistance gene
(Table 5). The distribution of infection types indicates that 80%
of all reaction types observed were classified as powdery mildew
resistance (score 0, 1 and 2). The most frequent score was 2
(75%). Ten lines had a score of 2 for most of the isolates used
and one line (476-2-2) scored 4 (susceptible) for more than 50%
of the isolates used.
In nine lines (82%), the presence of previously unknown
genes in combination with a specific one was detected (Table 3,
4). Two different resistance alleles Mlat and Mla7 were postulated
to be present in the tested lines. The most common resistance
allele in the tested lines was Mlat. This allele was postulated to be
present in nine (82%) of the tested lines. Allele Mla7 was postulated to be present in line 476-2-2 together with an unknown
gene or genes.
Postulation of resistance alleles
Hypotheses about the specific resistance genes present were
made by comparing the reaction spectra of the tested lines with
those of differential lines. Identification of resistance genes was
made by eliminating resistance genes not present in tested lines.
The next step was to determine the postulated and possible
resistance genes (Brown and Jørgensen 1991; Czembor and
Czembor 1998, 1999b). This was done on the basis of the gene
for gene hypothesis (Flor 1956).
Discussion
Results
Among the 135 landraces from Egypt, eight (6%) expressed
resistance to isolate R303 of E. graminis f. sp. hordei (Table 2). From
the three regions in Egypt from which the landraces originated
only landraces collected in Marsa Matrruh and north Sinai
expressed resistance to powdery mildew. All landraces collected
in As Sahra Ash Sharqiyah were susceptible to R303 isolate.
Many studies show that barley landraces are rich sources of
resistances to pests and pathogens. These landraces evolved
during the period of primitive agriculture by more or less deliberate selection by farmers to obtain plants with desirable characteristics. This selection favoured the plants best fitted to survive
and those which gave the highest yields of a good quality
product. As very susceptible plants gave no seed, this selection
resulted in plants which were not very susceptible to damaging
pests or diseases (Jørgensen 1994; Valkoun et al. 1995; Madeley
1996; Jørgensen and Jensen 1997; IPGRI 1999; Czembor and
Czembor 2000).
This study shows that barley landraces from Egypt are a
valuable source of resistance to powdery mildew. Of the 135
barley landraces from Egypt tested, eight (6%) showed resistance to E. graminis f. sp. hordei. The region of Marsa Matrruh is
worth noting out of the three regions of Egypt from which the
Table 2. Site of collection of eight barley landraces from Egypt showing resistance to powdery mildew
Landraces
ICARDA
coll. code
Altitude
(m asl)
Province
Site
El Gura; 214 km S Sheik Zwaied
Al Matareh; 12 km west Marsa
Matrruh
Em Rakham Bahri; 30 km west
Matrruh
Abu Lahu Bahri; 36 km NW Marsa
Matrruh
Samala; 10 km east Marsa Matrruh
Ras Al Hekma; 68 km east MatrruhAlexandria
Zaqawa village in Siwa oasis
El Hitabit in Siwa oasis
No.
IHAR no.
ICARDA no.
1
2
415
440
ICB 32493
ICB 32518
EGY87
EGY87
95
5
North Sinai
Marsa Matrruh
3
441
ICB 32519
EGY87
-
Marsa Matrruh
4
443
ICB 32521
EGY87
5
Marsa Matrruh
5
6
471
476
ICB 32549
ICB 32554
EGY87
EGY87
15
85
Marsa Matrruh
Marsa Matrruh
7
8
607
610
ICB 32998
ICB 33001
EGY89
EGY89
-5
-5
Marsa Matrruh
Marsa Matrruh
2
4
2
2
2
2
2
2
2
2
2
D17
6
2
1
1
GE
8
11
12
2
1
2
4
4
4
2
2
1
HL3/5 JEH11 MH1
9
Unidentified resistance allele not present in the Pallas isolines set.
2
2
2
58–74 59-11 63-1
1
Isolates
2
2
2
R13C
14
2
2
2
R63
15
2
2
2
R71/1
16
2
2
2
R86.1
17
2
2
2
R189
18
3
4
5
2
2
2
2
4
4
2
2
2
2
2
0
2
4
2
2
4
4
4
0
4
2
2
4
10
11
13
18
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
4
4
4
2
4
4
4
4
2
2
2
1
2
2
2
2
2
2
2
2
2
2
2
2
EmA30 HL3/ JEH11 MH1-2 R189
5-1
7
Unidentified resistance allele not present in the Pallas isolines set.
2
2
2
2
2
4
2
2
58 59 63 A6
-74 -12 -1
1
Isolates
22
23
2
2
2
1
2
2
2
2
2
2
2
1
2
2
2
2
2
2
2
2
2
4
2
2
R303 Ru3 TR2
21
2
2
2
2
0
4
2
2
En1/
A1
25
2
2
2
2
2
2
2
2
R303.1
26
2
2
2
0
2
4
0
2
E92
27
415-1-1
440-1-1
440-1-2
441-1-1
443-1-5
471-1-3
471-4-5
476-1-1
476-2-2
607-1-2
610-1-1
Landrace IHAR no.
0
0
0
4
0
1
0
0
0
0
0
0
0
0
0
4
0
0
2
2
0
0
0
1
18
19
18
15
15
13
13
13
10
17
20
2
0
0
0
0
0
0
0
0
0
0
0
3
No. of isolates that produced infection type
4
4
5
0
2
6
2
2
13
4
3
4
22
23
23
23
17
23
17
17
23
23
23
Total
Table 5. Infection types – frequency in 11 Egyptian landraces for isolates of E. graminis f. sp. hordei
†
415-1-1
440-1-1
440-1-2
441-1-1
471-1-3
476-2-2
607-1-2
610-1-1
Lines
2
2
2
2
2
4
2
2
59
-11.1
28
2
2
4
2
4
2
4
4
SZ/
C10
29
Table 4. Resistance alleles and infection types of eight lines to infection by 23 isolates of E. graminis f. sp. hordei
†
443-1-5
471-4-5
476-1-1
Lines
Table 3. Resistance alleles and infection types of three lines to infection by 17 isolates of E. graminis f. sp. hordei
2
2
2
2
2
2
2
2
Ra7
30
4
4
4
2
2
2
0
2
4
2
2
Ra9
31
R261
19
2
2
2
4
4
4
2
4
4
4
2
Ra10
32
R275
20
4
4
4
2
4
4
4
2
Ra13
33
2
2
2
R303
21
2
2
2
1
2
4
2
2
Ra16
34
2
2
2
Ry4d
24
2
2
2
2
2
4
0
2
Ra22
35
Mlat, +?†
Mlat, +?†
Mlat, +?†
+?†
Mlat, +?†
Mla7, +?†
Mlat, +?†
Mlat, +?†
Postulated
resistance
alleles
Mlat
Mlat, +?†
Mlat, +?†
Postulated
resistance
alleles
58
landraces originated, as the highest percentage (10%) of
landraces collected in this region expressed resistance to barley
powdery mildew. In addition, line 441-1-1, which possesses
resistance to all powdery mildew isolates used in this study,
originates from landraces collected in this area.
Based on the results of this study, the barley landraces
which will be collected in future germplasm collecting missions
in the Marsa Matrruh region should have high levels of powdery
mildew resistance. Organizing collecting expeditions in Egypt is
highly recommended because barley landraces in North Africa
are subject to genetic erosion due to drought and desertification
(Perrino et al. 1986; Damania 1988).
Isolates used in this experiment had virulency to all the
major resistance genes currently found in Europe. Therefore, it
can be concluded that line 441-1-1 is resistant to all the major
virulence genes present in populations of powdery mildew in
Europe. The distribution of infection types indicates the minimum number of genes involved because different genes for
resistance may elicit a different reaction type. Based on this
assumption, it may be concluded that line 441-1-1 may have
many genes for resistance. This line should be used in barley
breeding programmes as a new and very valuable source of
resistance to powdery mildew. The frequency of powdery mildew resistant landraces to all isolates of powdery mildew in the
present study was less than 1%, which is smaller or similar to
the findings of other studies (Honecker 1938; Nover and
Lehmann 1973; Czembor 1976, 1999; Czembor et al. 1979;
Negassa 1985; Lehmann and von Bothmer 1988; Leur et al. 1989;
Jørgensen and Jensen 1997; Czembor and Johnston 1999;
Czembor and Czembor 1999a, 2000). Divergences may relate to
differences in methods and isolates of powdery mildew used to
screen landraces for resistance in the different studies.
The presence of unknown genes alone or in combination
with specific ones was postulated to be present in 10 lines. Two
different resistance alleles Mlat and Mla7 were postulated to be
present in the lines. The most common resistance allele in the
tested lines was Mla, found in nine (82%) of the tested lines.
Allele Mla7 was present in line 476-2-2 together with an unknown gene or genes. These findings are in line with the fact
that virulence to these genes is common in the North African
mildew population (Yahyaoui et al. 1997). The presence in barley
landraces of a high number of genes different from the major
resistant genes used in Europe agrees with findings in other
studies (Honecker 1938; Nover and Lehmann 1973; Czembor
1976, 1999; Czembor et al. 1979; Negassa 1985; Lehmann and
von Bothmer 1988; Leur et al. 1989; Jørgensen and Jensen 1997;
Czembor and Johnston 1999; Czembor and Czembor 1999a,
2000).
New genes for resistance to barley powdery mildew are
needed. In the 20th century approximately 40 alleles for racespecific resistance to powdery mildew, either alone or in combination, have been used in Europe since the first gene, Mlg, was
introduced on a large scale in the 1930s in Germany. The most
common resistance genes used by barley breeders were Mla6,
Mla7, Mla9, Mla12 and Mla13 belonging to the Mla locus and the
resistance alleles Mlk, Mlg, MlLa, Mlh and Mlra (Brown and
Jørgensen 1991; Jørgensen 1992b, 1994; Czembor and Czembor
1998, 1999b). These genes have been used in approximately 700
cultivars. However, virtually all these genes are gradually overcome by virulent races within four to five years when cultivars
containing them are grown on a large acreage (Czembor and
Gacek 1987, 1995; Jørgensen 1992b, 1994; Wolfe and McDermott
1994). This occurs because E. graminis f. sp. hordei is able to
develop new races which rapidly spread across Europe on susceptible barley cultivars.
A high level of pathogenic variability in local populations
has been demonstrated in many studies (Limpert 1987;
Hovmøller and Østergård 1991; Huang et al. 1995; Müller et al.
1996). What is more, 28 alleles for resistance to powdery mildew
are closely linked or allelic. This limits the possible number of
gene combinations in breeding new barley cultivars (Czembor
and Gacek 1990, 1996; Brown and Jørgensen 1991; Czembor
and Czembor 1998, 1999b).
The use of genes originating from landraces for resistance to
powdery mildew should be a relatively easy task as there should
be no problems of sterility or other abnormalities that would
occur when mutants or some wild barley are used (Burdon and
Jarosz 1989; Jørgensen 1994). A good example of this is the
introduction of Mlo resistance into modern European barley
cultivars. All 25 different mlo alleles, with the exception of mlo11,
were obtained by mutagenesis. However, almost all barley cultivars with mlo resistance have the same allele mlo11, which originated from the Ethiopian landrace L92 (Jørgensen 1992a, b,
1994; Schwarzbach 1997)
Tests performed on seedlings for powdery mildew resistance
are usually sufficient for the needs of breeders and pathologists.
However, these tests do not necessarily predict the resistance of
the adult plant (Brown and Jørgensen 1991; Jensen and Jørgensen
1991; Jensen et al. 1992; Czembor and Czembor 1998, 1999b). The
new sources of resistance to powdery mildew in barley landraces
from Egypt, identified in this study, confer resistance against all,
or at least to a large number, of the powdery mildew virulence
genes present in Europe. Therefore, they can make a significant
contribution to the diversity of the powdery mildew resistance
genepool available to barley breeders.
Acknowledgements
The author thanks Drs J. Valkoun and S. Ceccarelli, ICARDA for
kindly providing seed samples of barley landraces from Egypt,
Dr H.J. Schaerer, ETH, Switzerland for the powdery mildew
isolates and Dr L. Munk, Royal Agricultural and Veterinary
University, Denmark for the Pallas near-isogenic lines.
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ARTICLE
Plant
Plant
Genetic
Genetic
Resources
Resources
Newsletter,
Newsletter,
2000,
2000,
No. No.
123:123
61 - 61
67
Genotypic variation of Kenyan tomato (Lycopersicon
esculentum L.) germplasm
S.G. Agong¹*, S. Schittenhelm² and W. Friedt³
¹ Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, PO Box 62000, Nairobi, Kenya.
² Institute of Crop Science, Federal Agricultural Research Centre, Braunschweig-Völkenrode (FAL), Bundesalle 50, D-38116
Braunschweig, Germany
³ Institute of Crop Science and Plant Breeding I, Justus-Liebig University Giessen, Ludwig Str. 23, D-3539 Giessen, Germany
Summary
Genotypic variation of Kenyan
tomato (Lycopersicon
esculentum L.) germplasm
Systematic genotypic analysis of Kenyan
tomato germplasm was carried out in
order to delineate potential variability
based on various morphological, agronomic and biochemical traits. Both
landraces and market cultivars were examined with a view to facilitating tomato
improvement. In an experiment conducted in 1993 in a glasshouse at the Federal Agriculture Research Centre (FAL),
Germany, 26 tomato landraces and nine
market cultivars were investigated using
a four-replicate completely randomized
block design. Analysis of variance clearly
illustrated a large variation for all the
quantitative traits. Landraces on average
produced more fruit per plant (90) but of
a smaller size than the market cultivars
(19). However, market cultivars had a
superior average fresh fruit weight of
56.5 g while the landraces registered on
average 40.6 g. Multiple correlation
analysis confirmed the superiority of
landraces for traits of fruit quality and a
strong negative association between
fruit biochemical parameters and fresh
fruit weight. Limited structural groupings were detected on the basis of a principal components analysis. Using this
method, processing and fresh tomato
cultivars within the germplasm could be
clearly separated on the basis of fruit
characters. Furthermore, this analysis
distinguished a few landraces from the
market cultivars, although closer phylogeny through introgression was highly
suspected. Within the landraces, the yellow-cherry types were distinct from all
the others. On the basis of this study, the
use of more prolific landraces, in terms of
number of fruit as well as actual fruit
yield, would be desirable for intensive
and continuous production of tomatoes.
Key words: Genetic diversity,
landraces, Lycopersicon esculentum,
phylogenetic relationships, principal
components analysis, tomato
Résumé
Resumen
Une analyse génotypique systématique du
matériel génétique de tomate du Kenya a
été effectuée en vue de définir la variabilité
potentielle sur la base de divers caractères
morphologiques, agronomiques et biochimiques. On a examiné tant les races locales que les cultivars commerciaux dans le
but de faciliter l’amélioration de la tomate.
Dans une expérience réalisée en serre en
1993 au Centre fédéral de recherche agricole (FAL) en Allemagne, 26 races locales de
tomates et neuf cultivars commerciaux ont
été étudiés à l’aide d’un dispositif de blocs
complètement randomisés avec quatre
répétitions. L’analyse de la variance a montré clairement une importante variation
pour tous les caractères quantitatifs. Les races locales ont donné en moyenne plus de
fruits par plante (90) mais ils étaient plus
petits que ceux des cultivars commerciaux
(19). Toutefois, les fruits frais provenant de
cultivars commerciaux ont affiché un poids
moyen supérieur (56,5 g), à celui des fruits
des variétés locales (40,6 g en moyenne).
Une analyse de corrélation multiple a confirmé la supériorité des races locales pour les
caractères de qualité des fruits et une association négative importante entre les
paramètres biochimiques des fruits et le
poids des fruits frais. Des groupements
structurels limités ont été détectés sur la
base d’une analyse en composantes principales. Par cette méthode, les cultivars de
tomates pour la transformation ou la consommation en frais pourraient être nettement séparés sur la base des caractères des
fruits. Cette analyse a aussi permis de différencier quelques races locales des cultivars
commerciaux, mais l’on soupçonne qu’il existe une phylogénie plus étroite par introgression. Parmi les races locales, les types
jaune-cerise se distinguent de tous les autres. Sur la base de cette étude, on peut
conclure que l’utilisation de races locales plus
prolifiques, en termes de nombre de fruits
et de rendement effectif en fruits, serait souhaitable pour une production continue et
intensive de tomates.
Se procedió a un análisis genotípico
sistemático del germoplasma del tomate
keniano para trazar la variabilidad potencial en función de diversos rasgos
morfológicos, agronómicos y bioquímicos. Se examinaron variedades locales y
cultivares comerciales con miras a facilitar la mejora del tomate. En un experimento realizado en 1993 en un invernadero del Centro Federal de Investigación
Agrícola (FAL) de Alemania, se investigaron 26 variedades locales de tomates y
nueve cultivares comerciales utilizando
un diseño en bloque cuadruplicado completamente aleatorio. El análisis de varianza ilustró claramente una amplia variación para todos los rasgos cuantitativos.
Las variedades locales produjeron en
promedio más frutos por planta (90),
pero de menor tamaño que los cultivares
comerciales (19). No obstante, los cultivares comerciales alcanzaban un promedio más alto de peso del fruto fresco: 56,5
g frente al promedio de 40,6 g de las
variedades locales. El análisis de correlación múltiple confirmó la superioridad
de las variedades locales en la calidad del
fruto y una fuerte asociación negativa
entre los parámetros bioquímicos del fruto y el peso del fruto fresco. Se detectaron
agrupaciones estructurales limitadas sobre la base de un análisis de componentes
principales. Con este método pudieron
separarse claramente, dentro del germoplasma, los cultivares de tomate frescos y
procesados, en función de las características del fruto. Por otra parte, este análisis
distinguió unas pocas variedades locales
de los cultivares comerciales, aunque
había fuertes sospechas de filogenia más
próxima por introgresión. Dentro de las
variedades locales, los tipos amarillocereza eran distintos de todos los demás.
Según este estudio, el uso de variedades
locales más prolíficas tanto en número de
frutos como en rendimiento efectivo del
fruto sería deseable para la producción
intensiva y continua de tomates.
Variation génotypique du
matériel génétique de tomate
du Kenya (Lycopersicon
esculentum L.)
Variación genotípica del
germoplasma del tomate
keniano (Lycopersicon
esculentum L.)
Introduction
With the increasing need of consumers for both quality and
diversity of tomato products, there is a need to extensively
collect, exploit and evaluate unknown tomato germplasm. To-
mato continues to play a key horticultural role in Kenya and its
improvement would enhance agricultural productivity, alleviate
poverty and facilitate food security (Agong and Schittenhelm
62
1993; Agong et al. 1997). However, most of the tomato
germplasm in the country is largely undocumented and has
unknown morphological, agronomic and biochemical attributes.
Tomato is continuously introduced and grown in all ecological
zones where arable agriculture is practicable. This tendency has
fuelled the extensive cultivation of various tomato cultivars with
unclear documentation (Agong and Schittenhelm 1993).
Systematic study and characterization of tomato germplasm
is of great importance for current and future agronomic and
genetic improvement of the crop. Furthermore, if an improvement programme is to be carried out evaluation is imperative, in
order to understand the genetic background and the breeding
value of the available tomatoes.
Morphological, agronomic as well as biochemical parameters have been widely used in the evaluation of various crops
(Rick and Holle 1990; Weber and Wricke 1994; Kaemmer et al.
1995). Exploitation of such traits increases our knowledge of the
genetic variability available and strongly facilitates breeding for
wider geographic adaptability, with respect to biotic and abiotic
stresses. In addition, genetic diversity needs to be described and
measured if it is to be effectively incorporated into breeding
strategies and management of plant genetic resources.
The objective of this study, therefore, was to examine the
variation in tomato germplasm based on the morphological,
agronomic and biochemical traits in the landraces, as well as
in market cultivars, with an ultimate view of identifying potential accessions to improve tomato production. This study
also aimed to generate data to increase understanding of the
phylogeny of the Kenyan tomato germplasm to improve effective management.
Tomato (Lycopersicon esculentum L.) accessions collected from
different parts of Kenya, as described by Agong and
Schittenhelm (1993) and Agong et al. (1997), were used in this
study. Germplasm was comprised mostly of landraces grown
by mainly small-scale farmers over several years, and collected
mainly in the western, central, eastern and coastal regions of
Kenya. These areas differ greatly in their agro-ecological and
ethnic compositions.
Morphological, agronomic and biochemical characterization of the tomato germplasm was conducted with the hypothesis that any differences among the tomato accessions
would be due to the genetic differentiation therein and not
solely to phenotypic plasticity, given the diverse environmental differences between the collection sites (Agong and
Schittenhelm 1993). Using a four-replicate randomized complete block design, a pot experimental study under a controlled glasshouse environment was conducted from February
to August 1993 at FAL. For each replicate, 12 plants per
accession were studied. In the experiment 35 accessions were
used, including three of German origin used as a control. The
tomatoes were grown in an organically enriched Völkenrode
compost soil following standard horticultural practice, as described in Agong et al. (1997). Throughout the experiment,
glasshouse temperatures were kept at 15°C at night and 25°C
during the day and relative humidity maintained at 70%. The
seedlings were pricked out into 26 cm plastic pots four weeks
after emergence and cultured up to bright-red fruit maturity.
The parameters scored during vegetative growth and
through fruit maturity included: total fruit set (% FS), total
number of fruit per plant (NF), fresh fruit weight per plant of
mature fruits (g FFW), plant height at fruit maturity (cm PH),
mature fruit dry matter content (% DC), dry fruit weight of
mature fruit (g DFW), mature fruit index (FI), thousand-seed
weight (g SW), electrical conductivity (dS/m EC), pH value
(pH), Brix (% BRI), titratable acidity (% TA), citric acid (mM/L
CA), malic acid (mM/L MA], fructose (% FRU) and glucose (%
GL) of mature fruit. Fruit juice extracts from each tomato accession were obtained and stored at -20°C for the chemical analysis. From each of the 12 plants per accession in every replication,
5 g of juice extract was obtained to provide a 60 g mixed juice
sample for use in the biochemical analyses.
Sampling was done carefully to ensure that fruit from all the
accessions was at an approximately similar physiological maturity (bright red ripe). Thawed juice samples were vigorously
shaken and used to determine the electrical conductivity and
pH values according to the procedures of Agong et al. (1997). The
percentage of total soluble solids was measured by the use of a
sucrose hand refractometer (model HRN-20 of Krüss-W.S.R.
Tokyo).
Sugars (glucose and fructose) and organic acids (citric and
malic) were analyzed from the homogenously mixed fruit-juice
extract using high performance liquid chromatography (HPLC)
as described by Mitchell et al. (1991). However, the sugars were
extracted in distilled water and not in 60% ethanol. The separation of sugars and organic acids was accomplished on an
AminexTM HPX-87H 300 x 7.8 mm column (BIO-RAD, Richmond, California) with a degassed 0.05 N H2SO4 as the mobile
phase (eluant) at a flow rate of 0.4 ml/min. Sugars were detected with a differential refractometer (RI-Detektor, Knauer)
and organic acids by UV absorbance at 210 nm. All samples
were run at a constant temperature of 30°C. Titratable acidity
was determined using the methods of the National Canners
Association (1968) and Agong et al. (1997).
By using the computer program SAS (SAS Institute Inc.
1990) an analysis of variance (ANOVA) was carried out to
determine the significance of differences. Multiple correlation
and principal components analysis (PCA) were carried out as
described by Broschat (1979) on the standardized and normalized mean values of the metric characters and correlation
matrices.
Results
The evaluation of the Kenyan tomato germplasm showed a
large and significant variation in the quantitative traits between
the accessions (Tables 1a, b). For example, the percentage of
fruit set was scored at 39.6 and 94.9% for accessions 7 and 24,
respectively. The average fresh and dry fruit weights varied
notably among the accessions. Most of the landraces gave lower
fresh and dry fruit yields than the market cultivars. On the other
hand, the landraces displayed superiority with respect to biochemical parameters. For example, landraces 29, 31 and 33 had
very high levels of Brix (Table 1b). Electrical conductivity for all
Table 1a. Accession means for yield-related characters in tomato
Accession no.
2M
3M
4M
5M
6M
7M
8M
9M
10M
11L
12L
13L
14L
15L
16L
17L
18L
19L
20L
21L
22L
23L
24L
25L
26L
27L
28L
29L
30L
31L
32L
33L
35GL
36GL
37GL
X‡
LSD(0.05)§
Character†
FS (%)
NF
FFW (g)
DFW (g)
FI
NS
SW (g)
DC (%)
89.4
70.3
76.4
90.3
79.0
39.6
74.1
71.3
79.3
69.9
61.8
58.6
78.4
65.8
78.9
82.0
85.5
64.1
72.3
81.7
72.0
79.5
94.9
58.8
80.4
48.9
79.2
89.1
74.6
83.9
79.0
84.9
98.5
46.0
95.7
75.3
10.7
22.0
13.5
24.7
24.6
27.3
10.1
19.4
14.5
17.3
26.5
24.3
27.0
23.0
34.9
27.5
26.8
47.1
33.0
21.2
28.9
72.9
44.0
83.7
30.1
26.3
11.2
25.1
158.9
28.0
115.2
21.0
73.4
103.1
9.7
14.0
37.4
4.6
35.9
92.6
49.4
37.0
39.1
83.3
48.4
65.8
57.0
35.2
31.5
33.0
41.7
30.2
42.7
37.8
16.9
28.8
51.2
35.1
7.9
15.7
14.7
43.5
45.0
82.1
39.0
2.6
33.7
4.3
55.8
8.2
5.4
90.7
80.4
40.6
7.2
3.4
7.2
4.2
2.6
2.9
7.6
4.0
7.5
4.1
2.6
2.7
2.3
3.1
2.3
4.9
2.9
1.4
2.5
3.8
3.0
0.8
1.6
1.3
3.2
3.4
3.4
5.2
0.3
2.4
0.4
4.4
0.8
0.5
8.4
6.4
3.4
0.7
0.96
1.47
1.24
0.86
0.81
1.44
0.92
1.30
1.47
0.87
0.95
0.80
1.17
1.02
1.33
1.26
1.50
1.29
1.34
1.19
1.37
1.33
0.81
1.30
1.25
1.39
1.18
1.04
1.00
1.06
1.07
1.23
1.03
1.49
1.51
1.18
0.08
66
160
131
64
58
170
51
151
72
74
69
77
119
87
141
93
107
117
112
80
80
113
42
111
95
200
109
73
67
96
121
91
49
196
119
102
13
2.53
2.80
3.06
3.27
2.81
2.68
3.42
2.99
3.77
3.23
3.00
3.12
3.21
2.52
2.89
2.86
2.64
2.90
3.01
2.89
1.93
2.41
2.02
1.92
2.89
2.60
3.09
1.11
2.93
1.24
3.32
1.79
2.00
2.65
2.79
2.69
0.17
9.6
7.7
8.5
7.2
7.4
9.1
8.3
11.4
7.1
7.5
8.6
6.9
7.4
7.7
11.5
7.7
8.4
8.6
7.3
8.6
10.5
9.8
8.6
7.4
7.6
4.2
13.4
11.0
7.2
10.4
7.9
10.2
9.8
9.2
8.0
8.6
0.8
†
See ‘Methods’ for character definition.
X = grand mean.
§
LSD(0.05) = least significant difference at 5% level.
FS = fruit set; NF = number of fruit per plant; FFW = fresh fruit weight; DFW = dry fruit weight; FI = mature fruit index; NS = no.
of seeds per fruit; SW = thousand-seed weight; DC = dry matter content; M = market cultivars; L = landraces of Kenyan origin;
GL = landraces of German origin.
‡
accessions ranged between 6.5 and 9.4 dS/m. Similarly, the fruit
juice extract of the landraces, particularly accessions 33 and 31,
had the highest electrical conductivity.
Correlation analysis revealed strong relationships among
the biochemical traits (Table 2). As expected, the weight of fresh
fruit was negatively associated to the fruit’s biochemical contents. Fresh fruit weight also correlated negatively to fruit number per plant and dry matter content. Positive correlationship,
however, was observed between fresh fruit weight and fruit
width and fruit equatorial length, whereas the number of fruit
per plant was negatively correlated to fruit width.
Visual appraisal of the germplasm during the vegetative
and the reproductive phases also showed that the accessions
were fairly variable. For example, observation of the reproduc-
tive parts revealed that accession 33, a red-cherry tomato, had a
pin flower form whereas the yellow-cherry and the market types
displayed the thrum flower structure (Fig. 1). Similarly the fruit
forms differed.
The PCA on 15 unrelated but linearly correlated quantitative
characters indicated that the first three principal components
were adequate in explaining more than 70% of the phenotypic
variation in the tomato germplasm (Fig. 2). However, no clear
classes could be adduced from the analysis. To some extent it
was possible to distinguish between accessions collected in the
western, central and coastal areas of Kenya. An approximate
classification is (a) landraces with yellow fruit from the coast,
(b) landraces with red-cherry fruit from western Kenya, (c) a
mixture of coastal, central and western accessions, (d) central
64
Table 1b. Accession means for biochemical attributes of tomato fruit
Accession
2M
3M
4M
5M
6M
7M
8M
9M
10M
11L
12L
13L
14L
15L
16L
17L
18L
19L
20L
21L
22L
23L
24L
25L
26L
27L
28L
29L
30L
31L
32L
33L
35GL
36GL
37GL
X‡
LSD(0.05) §
Character
†
EC
pH
BRIX (%)
TA (%)
GL (%)
FRU (%)
CA (mM/L)
MA (mM/L)
7.8
7.0
7.3
7.5
6.6
7.5
7.3
6.5
7.1
6.9
7.3
6.8
6.7
6.7
6.7
6.8
8.2
6.6
7.0
7.4
8.0
8.0
7.6
8.5
7.0
7.1
7.3
7.4
7.0
9.4
6.7
9.3
8.6
7.5
7.4
7.3
0.6
4.1
4.1
4.2
4.1
4.3
4.2
4.4
4.2
4.1
4.3
4.5
4.3
4.3
4.4
4.3
4.3
4.2
4.3
4.2
4.1
4.1
4.2
4.2
4.2
4.1
4.2
4.2
4.1
4.4
4.0
4.2
3.9
3.8
4.2
4.2
4.2
0.7
8.5
7.9
7.4
7.3
7.0
8.8
8.4
6.8
7.6
6.8
8.4
7.3
7.3
7.2
7.0
7.4
7.4
7.4
7.1
7.6
8.4
8.3
8.0
7.3
7.0
8.4
8.1
10.5
7.4
9.0
7.2
9.5
8.1
8.7
7.1
7.8
0.8
0.9
0.7
0.6
0.7
0.5
0.7
0.5
0.6
0.8
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.8
0.6
0.6
0.7
0.7
0.6
0.6
0.4
0.6
0.6
0.6
0.8
0.5
0.8
0.5
1.0
1.2
0.6
0.5
0.6
0.1
2.3
2.6
2.3
1.8
2.0
2.2
2.0
1.6
2.0
2.1
2.4
2.5
2.1
2.0
2.1
2.2
2.1
2.1
2.0
2.0
1.9
1.4
2.4
2.3
2.1
2.3
2.4
2.9
1.8
2.3
1.8
2.5
1.4
2.2
1.3
2.1
0.7
2.5
2.6
2.5
2.0
2.2
2.5
2.1
1.7
2.0
2.2
2.5
2.7
2.2
2.1
2.2
2.5
2.3
2.3
2.2
2.2
2.3
1.4
2.6
2.5
2.3
2.5
2.5
3.6
1.9
2.7
1.9
2.9
1.6
2.5
1.6
2.3
0.7
46
43
33
44
34
36
32
39
39
24
24
30
27
28
29
21
41
34
31
34
43
42
36
25
30
31
31
66
24
61
30
67
62
36
28
36
6
73
45
56
49
34
42
80
40
56
73
73
17
85
63
13
61
38
62
49
60
47
41
43
23
43
73
50
37
97
43
20
39
45
18
11
48
55
†
See ‘Methods’ for character definition.
X= grand mean.
§
LSD(0.05) = least significant difference at 5% level.
EC = electrical conductivity; TA = titratable acidity; L = glucose; FRU = fructose; CA = citric acid; MA = malic acid; M = market
cultivars; L = landraces of Kenyan origin; GL = landraces of German origin.
‡
accessions with large fruit, (e) coastal accessions with large fruit
and (f) a mixture of all accessions. Accessions 35, 36 and 37
were used for control purposes and do not affect the possible
genotypic classifications. Market cultivars can be separated into
three categories: 4 and 10; 3, 7 and 9; and 2, 5, 6 and 8. Tomatoes
for processing (2, 5, 6 and 8) could clearly be separated on the
basis of PCA analysis from the fresh market cultivars (3, 4, 7, 9
and 10).
Discussion
The heterogeneity observed in the germplasm is largely attributable to the genotypic variability within and between the individual tomato groups. The variation adduced in this study
conforms with earlier work on the reaction of this germplasm to
salinity stress (Agong et al. 1997). The availability of a base
variable population, for example red and yellow cherry fruiting
tomato types, is crucial for any significant progress in crop
genetic advancement. Genetic improvement of tomato should
not only depend on the introduction but also on the gradual
development of more closely adapted accessions suited to local
conditions (Agong 1995).
On the basis of the morphological, agronomic and biochemical data generated in this study on yield and yieldrelated traits, it is suggested that fruit number per plant and
fruit index (length/width), which are closely associated with
fresh fruit yield (Table 2), can be used to create a better understanding of diversity in the tomato for yield and crop improvement (Cavicchi and Silvetti 1976). The percentage of fruit set
and fruit number per plant were strongly correlated, hence this
relationship can be useful for effective pruning management
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
0.17
0.05
0.27
–
–
–
–
–
–
–
–
–
–
–
–
–
0.96**
0.34*
–0.07
0.36*
–
–
–
–
–
–
–
–
–
–
–
–
0.64**
0.51**
0.69**
–0.31
0.38*
†
EC = electrical conductivity, TA = titratable acidity.
* Significant at P = 0.05; ** significant at 0.01.
–
–
–
–
–
–
–
–
–
–
–
0.49**
0.14
–0.01
0.88**
–0.87**
0.03
–
–
–
–
–
–
–
–
–
–
0.62**
0.48**
0.19
0.08
0.63**
–0.55**
–0.07
–
–
–
–
–
–
–
0.70**
0.61**
–0.49**
–0.40*
–0.41*
–0.28
–0.14
–0.56**
0.17
–0.06
–
–
–
–
–
–
0.72**
0.22
0.79**
–0.61**
–0.59**
–0.55**
–0.28
–0.09
–0.69**
0.43**
–0.25
–
–
–
–
–
–0.47**
–0.32
–0.04
–0.36*
0.28
0.37*
0.38*
0.13
0.03
0.43**
–0.28
0.28
–
–
–
–
–0.34*
0.74**
0.74**
0.32
0.73**
–0.63**
–0.55**
–0.71**
–0.29
–0.12
–0.68**
0.29
–0.05
–
–
–
–0.78**
0.41*
–0.86**
–0.84**
–0.41**
–0.83*
0.54**
0.56**
0.64**
0.43*
0.22
0.76**
–0.39*
0.15
–
–
0.47**
–0.15
0.27
–0.40*
–0.50**
–0.61**
–0.18
0.24**
0.43
0.01
–0.16
–0.28
0.41
–0.36*
0.04
–
0.11
0.61**
0.49**
0.35**
–0.79**
–0.41**
0.14
0.73
0.48**
0.43**
0.44**
0.33
0.21
0.47**
0.41*
0.47**
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
no./
plant
%
cm
g
%
cm
cm
–
–
–
–
–
–
–
–
0.08
–0.20
–0.18
–0.03
0.01
0.09
–0.19
–0.04
0.22
–
–
–
–
–
–
–
–
–
–0.65**
–0.46**
–0.66**
–0.46**
–0.28
–0.67**
0.41*
–0.22
mM/L
%
%
%
%
dS/m
g
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–0.76**
0.02
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–0.06
mM/L
Malic
acid
Fruit
pH
Glucose Citric
acid
Fructose
Brix
Fruit
Plant Fruit
height set
Fresh
fruit/
plant
Dry
matter
content
Fruit
length
Fruit
width
Seed/
fruit
1000
seed
weight
EC
†
TA †
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Parameters
Table 2. Phenotypic correlations among the quantitative traits (morphological, agronomic and biochemical parameters) studied
16
17
as well as for predicting new selection procedures for crop improvement (Cavicchi
and Silvetti 1976).
The pH, total titratable acidity and Brix
are vital attributes with respect to the organoleptic quality of tomato fruit (Tigchelaar
1986; Mitchell et al. 1991; Agong 1995). On
average, most landraces had a high number
of biochemical attributes (Table 1b) and
these characteristics are definitely useful
where production tends to be for processing. Thus landraces may be a valuable
source of germplasm for the improvement
of processing tomatoes. The greater commercialization of these landraces would
strongly motivate and economically empower small-scale farmers who possess a
large portion of the germplasm.
The lack of definitive classification
based on the PCA strongly suggested closer
phylogenetic relationship amongst the tomato accessions (Fig. 2). Fruit characters
alone are unlikely to be suitable for evaluating tomato germplasm. The inclusion of
more morphological, agronomic and biochemical traits would be appropriate, especially in a multi-trait selection programme
for the improvement of horticultural characteristics (Broschat 1979). However, visual
appraisal of germplasm during the vegetative and the reproductive phases confirmed
genotypic variability within the germplasm
(Fig. 1).
These visual features were extremely
helpful in genotypic differentiation of the
landraces, such as the expression of stigma
above the anther cone in accession 33, suggesting the close phylogenetic relationship
of this landrace to the primitive progenitor
of tomato (L. esculentum var. cerasiformie),
known for its out-breeding tendency (Rick
1976; Alcazar-Esquinas 1981). From an evolutionary standpoint, if farmers have been
practising methods which encourage intense inbreeding, it is very likely that rare
genes will ultimately be expressed, thus exposing the wild phenotypes as observed in
accession 33. Modern tomato cultivars comprise strongly self-pollinating types that
have a limited chance of cross-pollination.
As expected, correlation analyses revealed that fresh fruit yield was negatively
associated to fruit number (Table 2). Thus,
if small-scale farmers have been selecting
for higher fruit number they might have
done so at the expense of improving yields.
Most tomato landraces had a higher num-
a
b
d
c
e
f
Fig. 1. Differentiation of the landraces from the market cultivars based on
flower and fruit forms. Stigma protrusion from, and enclosure within, the
anther cone as seen in ‘Nyaluo’ (a) and ‘Moneymaker’ (b) respectively.
Diversity in fruit forms: ‘Moneymaker’ (c), ‘Cal J’ (d), Tindi (e) and
‘Nyanyandogo’ (f).
ber of fruit per plant than the market cultivars, confirming their
mostly inferior fresh fruit yield in comparison to the market
cultivars, as evidenced elsewhere (Agong 1995). Over a long
time period the high production of fruit in landraces can substantially benefit urban and peri-urban communities. Thus
landraces can effectively be utilized under intensive and continuous tomato production systems.
Most of the biochemical characters were negatively correlated to fresh fruit yield (Table 1b). Therefore, a breeding
programme would sacrifice the larger fruit to obtain better quality, particularly when the main objective is to improve the
processing quality (Agong et al. 1997). Electrical conductivity,
Brix [%], pH value and total titratable acidity are used as criteria
to judge the organoleptic and processing qualities of tomato
and, therefore, require inclusion into breeding programmes
(Mitchell et al. 1991; Agong et al. 1997).
To conclude, based on current data, Kenyan tomato
landraces are found to be suitable for production systems
where processing is the commercial objective. Furthermore,
due to their ability to produce a high quantity of fruit over
time, their usefulness for improving tomato production under
intensive and continuous systems cannot be ignored. However, modern cultivars produce higher fruit yield and will
remain equally important for tomato improvement. In addition, due to the ever increasing rate at which tomato is introduced, there is a need to develop a reliable, faster and more
affordable cultivar characterization procedure in order to safeguard small-scale producers.
Acknowledgements
This work was accomplished with the help of a financial grant
from the German Academic Exchange Service (DAAD) to S.G.
Fig. 2. Plot of the three principal components in determining the genotypic relatedness of the tomatoes based on fruit quantitative characters. g = Standard
Kenyan tomato accessions; ? = West Kenyan tomato accessions; h= Central Kenyan tomato accessions; 6 = East/coastal Kenyan tomato accessions.
Agong. The authors also wish to thank Mr E. Sommer, Mr B.
Arnemann and Mrs C. Methner for their unfailing technical
support.
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landraces with special reference to salt and drought tolerance.
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68
ARTICLE
Plant Genetic Resources Newsletter, 2000, No. 123: 68 -77
Evaluation of the biological nitrogen-fixing ability of
lupin (Lupinus L.)
B.S. Kurlovich1*, L.T. Kartuzova1, B.M. Cheremisov1, T.A. Emeljanenko1,
I.A. Tikhonovich2, A.P. Kozhemyakov2 and S.A. Tchetkova2
N.I. Vavilov Institute of Plant Industry, 190000, B. Morskaya str. 44, St. Petersburg, Russia.
Present address (B.S.K.): Leppälaaksontie 5, as 1. 52420, Pellosniemi, Finland. Tel: +358 4051-38657
2 Research Institute for Agricultural Microbiology, 189620, St. Petersburg-Pushkin 8, Russia
1
Summary
Résumé
Resumen
Evaluation of the biological
nitrogen-fixing ability of lupin
(Lupinus L.)
Evaluation de l’aptitude du lupin
(Lupinus L.) à fixer l’azote
Evaluación de la capacidad del
altramuz (Lupinus L.) para la
fijación biológica de nitrógeno
Accessions of lupin (Lupinus L.) with different origins (N=1050), drawn from the
N.I. Vavilov Institute collection, were
tested to reveal their nitrogen-fixing ability. Three treatments were used: (1)
without inoculation of seed with Russian
industrial strains of Bradyrhizobium sp.
(Lupinus) and mineral nitrogen application (control), (2) with seed inoculation
with Bradyrhizobium lupini (biological N),
and (3) with an application of mineral
nitrogen (mineral N). The results obtained demonstrated the different accessions of lupin with high nitrogen-fixation
ability, the most effective nodule bacteria
strains, and the complementary symbioses of plant and bacteria best able to accumulate nitrogen from the atmosphere.
The results are used to discuss aspects of
lupin diversity and suggest programmes
for lupin selection for high-intensity symbiotic nitrogen fixation.
On a testé des obtentions de lupin (Lupinus L.) d’origines différentes (N=1050),
provenant de la collection de l’Institut
N.I. Vavilov, en vue d’établir leur aptitude à fixer l’azote. On a utilisé trois traitements: 1) sans inoculation des semences
avec des souches industrielles russes de
Bradyrhizobium
sp.(Lupinus)
et
l’application d’azote minéral (témoin), 2)
avec inoculation des semences avec
Bradyrhizobium lupini (N biologique), et
3) avec une application d’azote minéral
(N minéral). Les résultats obtenus ont
montré les différentes obtentions de lupin à forte aptitude à fixer l’azote, les
souches bactériennes des nodosités très
actives, et les symbioses complémentaires de plantes et de bactéries pouvant
mieux accumuler l’azote atmosphérique.
On s’appuie sur ces résultats pour examiner des aspects de la diversité des lupins
et proposer des programmes de sélection des lupins pour une fixation symbiotique de l’azote à haute intensité.
Keywords: Bradyrhizobium sp.
(Lupinus), breeding, lupin diversity,
Lupinus L., nitrogen fixation
Se realizaron pruebas con accesiones de
altramuz (Lupinus L.) de diversos orígenes (N=1050), tomadas de la colección
del Instituto N.I. Vavilov, para observar
su capacidad de fijación de nitrógeno. Se
utilizaron tres tratamientos: 1) sin inoculación de semilla con variedades industriales rusas de Bradyrhizobium sp. (Lupinus) y aplicación de nitrógeno mineral
(control), 2) con inoculación de semilla
con Bradyrhizobium lupini (N biológico),
y 3) con una aplicación de nitrógeno mineral (N mineral). Los resultados obtenidos pusieron de manifiesto las diferentes
accesiones de altramuz con alta capacidad
de fijación de nitrógeno, las variedades
de bacterias nodulares más efectivas y las
simbiosis complementarias de planta y
bacteria más aptas para acumular nitrógeno de la atmósfera. A partir de los
resultados se considera la diversidad del
altramuz y se proponen programas de
selección de altramuz con miras a una
alta intensidad de fijación simbiótica de
nitrógeno.
Introduction
The genus Lupinus L. has hundreds of species (Cowling 1994;
Gladstones 1974, 1998), divided by origin into two clear groups
(Kurlovich 1988; Kurlovich et al. 1995): one from the Mediterranean (subgen. Lupinus), and the other from America (subgen.
Platycarpos (Wats.) Kurl.). The species are highly variable for the
majority of characters, including their ability to fix nitrogen,
which is determined by the efficiency of interaction between the
lupin plants and the different nodule bacteria strains.
The Lupinus genus is nodulated by the soil microorganism
Bradyrhizobium sp. (Lupinus). Bradyrhizobia are encountered as
microsymbionts of other leguminous crops (Argyrolobium, Lotus,
Ornithopus, Acacia) of Mediterranean origin (Allen and Allen 1981;
Jordan 1982; Legocki et al. 1997; Howieson et al. 1998). Many
aspects of the Lupinus-Bradyrhizobium sp. (Lupinus) symbiosis have
not been well investigated, especially from the point of view of
genetic resources. The purpose of our work was to look at the
diversity of lupin accessions in terms of biological nitrogenfixing ability, and relate them to the most effective nodule
bacteria strains and complementary symbioses (plants and
nodule bacteria strains) for nitrogen fixation.
The material for research was made up of 1050 accessions from
the N.I. Vavilov collection representing four species of lupin
with various ecogeographical origins from the Mediterranean
and 16 species from America. The principal accessions and
species are specified in the tables in the Results section.
Three treatments were used in evaluating the accessions:
1. Without inoculation of seed with Bradyrhizobium sp. (Lupinus)
and mineral nitrogen application (control).
2. Seed inoculation with Bradyrhizobium lupini (biological N).
Three widely used industrial Russian strains of Bradyrhizobium sp.
(Lupinus) – 363A, 367 and 375A – produced in the All-Russian
Research Institute for Agricultural Microbiology were used for
inoculation.
3. Mineral nitrogen application (mineral N). For the mineral N
treatment, ammoniac saltpeter was introduced at a rate of 60 kg
active ingredient per hectare.
The research was conducted between 1988 and 1998 in the
field at Pavlovsk Experimental Station of the N.I. Vavilov Institute of Plant Industry, 20 km from St. Petersburg. The soil of the
plot was a derno-podzolic acid loam that had not been fertilized
for several years. Accessions were tested at the same density of
30 plants/m2 under standardized conditions (Kurlovich et al.
1990, 1995, 1997). Nitrogenase activity was determined using
Institute for Agricultural Microbiology recommendations
(Alisova and Chunderova 1982).
Results
Growth and development of plants
Inoculating seed with Bradyrhizobium sp. (Lupinus) did not increase germination or change the duration of the vegetative
period. However, distinctions between plants of control variant
(without inoculation with Bradyrhizobium lupini and mineral N
application) and variant with inoculation were detected early.
In the first case the colouring of lower leaves of plants was
yellow, and higher leaves were yellow-green. In variants with
application of biological and mineral N, all leaves were bright
green. These colour differences were maintained up to the flowering phase. Subsequently, plants of the control acquired more
green colouring, but colour intensity was much less than in
inoculated plants.
Root nodule formation
White lupin (Lupinus albus L.)
All control accessions had plants without nodules. More often,
these plants were weaker and stunted. However, most of the
treated plants had from one to seven large (maximum diam. 20
mm), dense and uneven nodules, located singly, on the side
radicals. There were some exceptions to this pattern. On one (k507 from Egypt), nodules were also detected on the central
radical and the side radicals; their size reached 23-28 mm in
diameter. A large number of nodules (up to 45) were observed on
plants of three samples (k-1930 from Sudan, and k-2589 and
2617 belonging to West-European agrogeotype); however, their
size did not exceed 8 mm.
The inoculation variant differed sharply in all morphological
parameters from the control. Inoculated plants had a greater
number of smooth nodules (2-7 mm
diam.) placed evenly on all root systems. Number of nodules varied in
different plants and samples, but in
all cases there were many.
of yellow lupin (k-2292 from Portugal), compared with the roots
of a commercial variety (‘Akademichesky 1’) under inoculation
with Bradyrhizobium sp. (Lupinus). Variety ‘Akademichesky 1’ was
used in our experiment with yellow lupin as control. Of the
accessions without inoculation and with mineral N application,
samples k-2290 and k-2292 were the least responsive, and no
nodules were formed. In cv. ‘Augy’ from Lithuania, nodules
were densely located on all main radical roots. Nodules in the
control were more protuberant than in experimental variants.
Lupinus pilosus Murr.
In the control the uniform distribution on the root system of
separate nodules of a very large size (up to 15 mm) was characteristic. In the inoculated experimental variant, nodules were
pinker and frequently located on a main root.
Species of lupin from America
The majority of investigated species of lupin from America had
nodules on the root systems. The exceptions were three species
(L. affinis Agardh, L. barkeri Lindl. and L. succulentus Dougl.), in
which on the control the root system was poorly branched and
without nodules. Depending on the species of lupin and source
of N, nodules had unequal size, form and colour. The majority
of species grew round nodules that surrounded main and side
radicals, their sizes varied depending on species. Thus, on plants
of L. paniculatus Desr. the half-couplings and couplings reached
20 mm. More often they were elastic, almost smooth thickenings, but sometimes protuberant. Plants of L. douglassii Agardh
had marked, comblike couplings. The colour of nodules changed
depending on species of lupin and treatments. Nodules occurred on all root systems (L. mutabilis Sweet.), or mainly on the
main radical (L. pubescens Benth), or only on the side radicals (all
species on mineral N treatment). In plants that received the
mineral N, the root systems were strongly advanced. However
the presence of ammoniac saltpeter decelerated development of
nodules. They were fewer and placed mainly on the side radicals, more often as a bead-necklace formation.
Narrow-leafed lupin (L.
angustifolius L.)
Accessions of this species also had
the most nodules when inoculated
with Bradyrhizobium sp. (Lupinus).
Nodules were larger, placed as couplings and half-couplings.
Yellow lupin (L. luteus L.)
Inoculated accessions from Portugal, particularly k-2290 and k2292, had a large number of nodules. Figure 1 shows the root systems with nodules in the wild form
Fig. 1. Root systems with nodules of the wild form of yellow lupin k-2292 from Portugal
(right), compared with the roots of commercial variety ‘Akademichesky 1’ (left) under
inoculation with Bradyrhizobium sp. (Lupinus).
70
Nitrogenase activity
One important parameter in the process of biological nitrogen
fixation is the nitrogenase activity (Alisova and Chunderova
1982; Kurlovich et al. 1995; Van Kammen 1995). This parameter changes during the growth and development of plants
(Table 1). In healthy plants the nitrogenase activity can be
rather high up to the phase of green maturity of seed. However
in plants infected with fusarium wilt (e.g. L. angustifolius), nitrogenase activity was sharply reduced in this phase. Nitrogenase activity is dependent on a number of factors: experimental treatments, species and varieties features (belonging to
different geotype, ecotype or variety type), the presence of
spontaneous populations of nodulating bacteria or industrial
strains of rhizotorfin. Coefficient of variation (CV, %) of the
Table 1. Intensity of nitrogenase activity in lupin through the stages of development (Mmol C2H4 h-1 plant-1)
Stages of plant development
VIR no.
Species
Vars., cvs., access.
blossoming
flowering
of seed
green maturity
2644
2603
1981
2949
2159
2267
193
L. albus L.
L. albus L.
L. angustifolius L.
L. angustifolius L.
L. mutabilis Sweet.
L. ornatus Dougl.
L. succulentus Dougl.
Start
Druzba
Nemchinovsky 846
Danko
-
5.91
9.39
4.89
8.16
49.87
9.21
0.06
8.20
9.94
8.10
5.77
87.21
11.95
0.06
4.74
18.30
0.87
0.35
86.95
12.80
0.05
Table 2. Nitrogenase activity in nodules of lupin (at flowering stage) with 375A industrial strain of
Bradyrhizobium sp. (Lupinus) bacteria
Nitrogenase activity (Mmol C2H4 h-1 plant-1)
VIR no.
Species
Access., vars., cvs.
Origin
Lupins from Mediterranean (subgen. Lupinus)
L. albus L.
Start
Russia
2644
2603
L. albus L.
Druzba
Ukraine
L. angustifolius L.
Danko
Belarus
2949
L. angustifolius L.
–
France
2868
2866
L. angustifolius L.
Apendrilon
Greece
L. angustifolius L.
–
Russia
1379
L. angustifolius L.
–
Russia
1980
1981
L. angustifolius L.
Nemchinovsky 846
Russia
L. angustifolius L.
Timir–1
Russia
2664
L. luteus L.
Augy
Lithuania
2956
2298
L. luteus L.
Cyt
Poland
L. luteus L.
–
Portugal
2289
L. luteus L.
–
Portugal
2291
2292
L. luteus L.
–
Portugal
L. luteus L.
–
Spain
2865
L. luteus L.
Kopylovsky
Ukraine
2601
2649
L. luteus L.
Foton
Ukraine
L. pilosus Murr.
–
Greece
304
Lupins from America (subgen. Platycarpos (Wats). Kurl.)
1572
L. affinis Agardh
–
Canada
L. albococcineus Hort.
–
USA
2791
L. aridus Dougl.
–
Colombia
2543
1385
L. barkeri Lindl.
–
Mexico
L. douglassi Agardh
–
Mexico
1425
L. elegans H.B.K.
–
Mexico
113
2110
L. hartwegii Lindl.
–
Mexico
L. micranthus Dougl.
–
Canada
1733
L. mutabilis Sweet.
–
Peru
2159
1387
L. nanus Dougl.
–
Colombia
L. ornatus Dougl.
–
USA
2267
L. paniculatus Dougl.
–
Canada
1960
208
L. pubescens Dougl.
–
Ecuador
L. subcarnosus Hook
–
USA
2920
–
USA
193
1954
L. truncatus Nutt.
–
Mexico
Avg.
Min.
Max.
CV (%)
8.20
6.94
5.77
7.46
9.23
13.64
6.05
8.10
7.32
93.10
5.52
10.59
11.69
15.89
11.53
15.42
9.47
17.16
2.79
2.27
1.46
1.22
0.11
6.49
2.23
1.94
1.80
34.58
0.24
0.53
9.45
2.34
5.57
4.66
0.15
0.72
15.69
15.60
9.54
16.52
19.54
21.59
19.11
12.33
17.20
142.70
16.82
17.84
16.46
38.14
18.04
30.06
36.69
43.29
39.6
41.5
15.5
58.2
76.5
44.2
62.1
56.2
61.5
45.6
71.4
89.3
17.9
48.1
18.2
15.2
82.6
105.1
0.09
8.63
13.18
0.09
4.03
21.39
20.63
10.33
87.21
8.09
11.95
39.84
22.05
6.89
0.06
8.46
0.00
0.19
3.19
0.00
1.02
2.13
2.03
1.01
34.00
0.75
0.33
9.24
6.31
0.82
0.00
1.58
0.45
14.93
26.67
0.37
9.90
66.64
95.66
22.03
136.00
26.19
27.41
97.85
38.78
14.44
0.42
19.17
179.3
55.1
52.1
142.7
80.9
86.8
133.9
52.5
42.5
97.5
78.2
64.9
50.1
71.5
225.8
70.0
level of nitrogenase activity ranged in species from 15.1 to
255.8% (Table 2).
The highest nitrogenase activity was in L. mutabilis, the lowest in L. succulentus. Large variability of this parameter was
recorded in the lupin species assessed: in yellow lupin ‘Augy’
(k-2956), nitrogenase activity reached 142.70 Mmol C2H4 h-1
plant-1 (Table 2), and in variety ‘Cyt’ (k-2398), belonging to the
same species, it changed within the limits of 0.24-16.82 Mmol
C2H4 h-1 plant-1. The high nitrogenase activity of variety ‘Augy’
promoted increased accumulation of dry weight of plants
(Table 3). The positive correlation between nitrogenase activity
and accumulation of dry substance, and sometimes also of
protein content, has been established for many species of
lupin.
Accumulation of green and dry matter and N in
plants
The efficiency of symbiosis is best measured on the accumulation in plants of dry matter (DM) and nitrogen. Research has
shown that the application of nodulating bacteria Bradyrhizobium
sp. (Lupinus) in most cases increases the efficiency of plants. In
some samples the increase in the total DM under inoculation
with Bradyrhizobium sp. (Lupinus) bacteria was larger than under
application of mineral N.
White lupin (L. albus L.)
Studied accessions responded differently to inoculation with
B. lupini (Table 3). The maximum increase of green and dry
weight (6.18 times) was measured in the sample from Greece (k-
2864), and the minimum (1.17-1.21 times) in variety ‘Tambovsky
86’ from Russia and sample k-682 from former Yugoslavia. In
variety ‘Druzba’ from the Ukraine, in contrast, the total DM
under application of Bradyrhizobium bacteria decreased. Other
accessions that produced a good increase in crop yield (in
comparison with control) when inoculated were: cvs. ‘Start’ (k2644) from Russia, ‘Olezka’ (k-2980) from Ukraine, accessions
k-2989 and k-3250 from Portugal, ‘El Harrach-1’ (k-3110) from
Algeria. Among the investigated samples, the greatest total DM
in all treatments was from k-507 from Egypt, k-1930 from
Sudan and k-2986 from Portugal.
Narrow-leafed lupin (L. angustifolius)
Most accessions showed increased plant productivity after application of B. lupini. The best efficiency was in: cvs. ‘Ladny’ and
‘Nemchinovsky 846’, ‘Determinant-2’ (k-3365) and ‘Determinant-3’ (k-3366) from Russia, k-3065 from Australia, ‘Apva’ (k2950), ‘Vika 65’ (k-2954), ‘DG-94’ (k-3351) and ‘DG-95’ (k3352) from Belarus, wild forms k-3076, k-3079 from Spain, k3083 from Portugal and k-3093 from Morroco (Fig. 2). So for
example, application of B. lupini to the commercial Russian variety ‘Nemchinovsky 846’ increased the dry matter weight from
17.8 to 20.5 g. In this variety also the increase in accumulation
of N was revealed (Table 4). In many cases increased plant
productivity after inoculation with B. lupini was more significant
than after application of mineral N. However, inoculation did
not increase productivity of specimens and varieties from Palestine (k-288), Greece (k-2866) or of accessions from Australia (k2632, k-3062).
Fig. 2. Effect of inoculation of Lupinus angustifolius L. (var. ‘Nemchinovsky 846’ from Russia, and var. ‘Yandee’ from
Australia) with different strains of Bradyrhizobium sp. (Lupinus).
72
Table 3. Accumulation of dry matter in plants (g/plant) on different backgrounds of nitrogen nutrition
Treatment (DM in g/plant)
VIR no.
Species
3110
L. albus L.
El Harrach–1
L. albus L.
–
507
L. albus L.
–
484
2589
L. albus L.
Lublanc
L. albus L.
–
2617
L. albus L.
–
2864
294
L. albus L.
–
L. albus L.
–
1602
L. albus L.
Line 802–15
2623
2986
L. albus L.
48B
L. albus L.
–
2989
L. albus L.
–
3250
1596
L. albus L.
Snezinka
L. albus L.
Start
2644
L. albus L.
Tambovsky 86
2806
1930
L. albus L.
–
L. albus L.
Druzba
2603
L. albus L.
Olezka
2980
L. albus L.
–
682
L. angustifolius L.
Unicrop
2096
L. angustifolius L.
Yandee
2632
L. angustifolius L.
Line 75A/326
3061
L. angustifolius L.
–
3062
L. angustifolius L.
Line 75A/330
3064
L. angustifolius L.
–
3065
2681
L. angustifolius L.
Vada 10
L. angustifolius L.
Apva
2950
L. angustifolius L.
Jniven
2953
2954
L. angustifolius L.
Vika 65
L. angustifolius L.
DG–94
3351
L. angustifolius L.
DG–95
3352
2866
L. angustifolius L.
Apendrilon
L. angustifolius L.
Melkosemianny
1354
L. angustifolius L.
–
3093
3094
L. angustifolius L.
–
L. angustifolius L.
–
3097
L. angustifolius L.
–
288
2570
L. angustifolius L.
Mirela
L. angustifolius L.
Emir
2662
L. angustifolius L.
Mut–1
2801
3083
L. angustifolius L.
–
L. angustifolius L.
–
3084
L. angustifolius L.
–
3087
3090
L. angustifolius L.
–
L. angustifolius L.
Nemchinovsky 846
1981
L. angustifolius L.
Ladny
2648
3365
L. angustifolius L.
Determinant–2
L. angustifolius L.
Determinant–3
3366
L. angustifolius L.
Determinant–4
3367
3076
L. angustifolius L.
–
L. angustifolius L.
–
3079
L. angustifolius L.
–
3081
3082
L. angustifolius L.
–
L. luteus L.
Akademichesky 1
1947
L. luteus L.
Augy
2956
2398
L. luteus L.
Cyt
L. luteus L.
–
2089
L. luteus L.
–
2291
2290
L. luteus L.
–
L. luteus L.
–
2292
L. luteus L.
–
2865
Origin
Control
Biol. N
Mineral N
Algeria
Egypt
Ethiopia
France
France
Greece
Palestine
Poland
Portugal
Portugal
Portugal
Portugal
Russia
Russia
Russia
Sudan
Ukraine
Ukraine
Yugoslavia
Australia
Australia
Australia
Australia
Australia
Australia
Belarus
Belarus
Belarus
Belarus
Belarus
Belarus
Greece
Latvia
Morocco
Morocco
Morocco
Palestine
Poland
Poland
Poland
Portugal
Portugal
Portugal
Portugal
Russia
Russia
Russia
Russia
Russia
Spain
Spain
Spain
Spain
Belarus
Lithuania
Poland
Portugal
Portugal
Portugal
Portugal
Spain
17.9
30.3
30.1
14.6
14.5
15.0
25.1
22.6
27.0
29.5
19.6
20.1
16.8
15.1
15.0
30.2
20.7
19.6
19.4
16.7
16.8
22.5
15.0
20.1
19.2
15.2
19.2
17.9
19.0
24.5
25.6
2.1
20.5
28.0
26.5
27.5
18.2
19.5
16.8
22.2
16.2
15.1
17.6
16.3
17.8
13.5
16.8
16.5
15.5
18.5
19.0
14.6
14.3
16.2
24.2
6.6
19.5
13.8
9.7
10.1
9.3
26.5
33.6
32.9
16.2
16.3
85.1
28.2
24.2
29.5
32.6
25.9
26.9
18.2
20.9
15.3
33.6
20.0
26.8
19.9
18.5
15.9
24.6
14.2
23.8
23.6
20.3
22.1
19.5
21.0
27.8
28.3
2.1
22.6
32.1
30.1
31.0
16.5
24.8
21.3
24.6
18.5
17.3
18.5
18.5
20.5
17.8
20.4
19.3
18.2
22.4
23.2
16.2
16.0
18.5
20.7
10.2
17.5
12.6
19.6
20.1
13.0
25.2
33.0
33.5
16.0
16.0
25.2
28.0
24.5
30.0
30.0
25.1
27.0
18.5
21.0
17.3
34.1
22.5
25.1
19.5
20.0
20.2
25.0
22.0
24.0
25.0
20.0
20.0
20.2
20.0
28.0
28.0
6.5
24.0
30.5
30.0
32.5
24.2
22.3
20.5
25.0
19.0
17.0
19.1
18.0
20.8
17.2
20.0
19.5
19.0
22.0
24.8
19.0
17.2
Treatment (DM in g/plant)
VIR no.
Species
2869
L. luteus L.
–
L. luteus L.
–
3070
2000
L. luteus L.
T–12
L. luteus L.
Sojuz
2610
L. luteus L.
Foton
2649
304
L. pilosus Murr.
–
L. affinis Agardh
–
1572
2791
L. albococcineus Hort.
–
L. aridus Dougl.
–
2543
L. barkeri Lindl.
–
1385
1425
L. douglassi Agardh.
–
L. elegans H.B.K.
–
113
L. hartwegii Lindl.
–
2110
1733
–
L. mutabilis Sweet.
–
2159
L. nanus Dougl.
–
1387
2267
L. ornatus Dougl.
–
–
1960
L. pubescens Benth.
–
208
2920
L. subcarnosus Hook.
–
–
193
L. truncatus Nutt.
–
1954
Origin
Control
Biol. N
Spain
Spain
Sweden
Ukraine
Ukraine
Greece
21.5
8.5
18.3
16.8
16.6
9.9
16.1
12.3
22.4
21.8
23.2
9.5
Canada
USA
Colombia
Mexico
Mexico
Mexico
Mexico
Canada
Peru
Colombia
USA
Canada
Ecuador
USA
USA
Mexico
1.83
8.10
10.81
4.85
4.53
5.45
9.10
9.67
32.40
1.52
9.52
5.29
4.22
6.83
4.51
1.47
4.58
5.52
6.28
3.13
3.67
6.48
5.52
6.64
27.86
1.52
6.36
4.37
3.72
2.29
5.52
1.43
Mineral N
4.64
14.48
16.39
6.32
10.90
7.80
7.26
5.86
41.75
3.68
8.90
7.55
9.91
8.71
8.94
1.56
Table 4. The contents and accumulation of N in lupin plants with different N sources
VIR no.
Species
2398
L. luteus L.
Cyt
L. luteus L.
Augy
2856
L. albus L.
Druzba
2603
2644
L. albus L.
Start
L. angustifolius L.
Danko
2649
L. angustifolius L.
Nemchinovsky 846
1981
304
L. pilosus Murr.
–
L. mutabilis Sweet.
–
2159
2543
L. aridus Dougl.
–
–
1733
L. ornatus Dougl.
–
2267
2791
L. albococcineus Hort. –
L. hartwegii Lindl.
–
2110
L. subcarnosus Hook. –
2920
1960
–
L. pubescens Benth.
–
208
L. elegans H.B.K.
–
113
1425
L. douglassii Agardh.
–
L. barkeri Lindl.
–
1385
–
193
1387
L. nanus Dougl.
–
L. truncatus Nutt.
–
1954
L. affinis Agardh.
–
1572
N content of plants (%)
Accumulation of N (mg/plant)
Control
Biol.
N
Control
Biol.
N
3.90
3.82
3.00
3.56
2.99
2.59
2.47
3.80
3.25
3.06
3.03
2.71
2.60
2.70
257
922
622
537
574
461
244
389
674
616
511
512
532
256
2.94
3.14
3.44
3.18
2.89
2.58
2.45
3.18
3.36
2.44
2.86
2.25
2.26
3.20
3.12
2.44
2.46
3.03
3.32
3.11
3.15
2.32
2.73
3.18
3.40
2.41
–
2.50
2.60
3.47
2.97
2.37
953
339
333
303
234
235
167
168
142
133
130
109
102
49
46
45
684
190
220
198
174
129
171
169
127
156
–
178
144
53
43
109
Yellow lupin (L. luteus)
The greatest increase of dry matter under inoculation (99%)
appeared in wild forms k-2290 and k-2292 from Portugal, and
cv. ‘Cyt’ (k-2398) from Poland. ‘Cyt’ also showed an increase in
accumulation of N (Table 4). Figures 3 and 4 show the size of
Mineral
N
2.83
3.32
3.52
3.47
3.05
2.65
2.58
3.07
3.30
2.85
3.20
2.60
2.73
2.89
3.11
2.46
Mineral
N
1182
544
206
309
442
192
224
232
327
222
349
164
244
106
49
114
inoculated plants of the wild form k-2292 from Portugal (Fig. 3),
and cv. ‘Cyt’ (k-2398) from Poland (Fig. 4), compared with the
control.
However, for cv. ‘Augy’ from Lithuania, and also samples k2289 and k-2291 from Portugal, the application of the bacterial
74
strain 375A did not result in either an increase of dry matter or
of N. Despite this, cv. ‘Augy’ had the greatest total DM of all
investigated samples, both with inoculation of B. lupini and
especially without it.
Lupinus pilosus Murr.
For inoculated accession k-304, green and dry weight did not
increase (Table 3), although the contents and accumulation of N
did increase (Table 4).
Species of lupin from America
These species were unresponsive to application of the nodulating bacteria strains 367A and 375A. Maximum accumulation of
dry matter and N for almost all species from America occurred
with application of mineral N. The exceptions were L. micranthus
Dougl. and L. hartwegii Lindl., which were unresponsive to both
inoculation with the industrial strain of bacteria, and the application of mineral N. The greatest amount of accumulated N in
all three treatments was in L. mutabilis Sweet. Of interest as source
material for selection for increased nitrogen-fixation ability are
the following species: L. aridus Dougl., L. micranthus Dougl., L. ornatus
Dougl., L. albococcineus Hort.
In these experiments, also studied was the response of the
fodder low-alkaloid multifoliate Washington lupin (L. polyphyllus
Lindl.) to inoculation with strains of nodule bacteria in pure
state and in combination with the biostimulator lentechnin and
root diazotrops of the genus Arthrobacter (Table 5). Best results
were received when inoculating the Washington lupin (cv.
‘Truvor’) with nodule bacteria strain 1625. Combining inoculation with seed treatment with lentechnin was also found to be
efficient. Root diazotrops from Arthrobacter sp. did not show
great efficiency in this combination.
Fig. 3. Comparative sizes of plants of wild form k-2292 from
Portugal (Lupinus luteus L.), inoculated with Bradyrhizobium
lupini (right), and control variant (left).
Discussion and conclusions
As our research has shown, the evaluation of lupin accessions
from different origins under treatments with biological and
mineral N is rather effective. As a result of these experiments,
the large differences in responses of various species and accessions of lupin to inoculation with nitrogen-fixing bacterial
strains of Bradyrhizobium sp. (Lupinus) are revealed. The majority of
investigated accessions showed rather high responsiveness to
inoculation with commercial strains of Bradyrhizobium sp. The
low or negative effects of inoculation in some accessions (especially from America) we explain by mismatch of the strains of
bacteria used to plant genotypes. It testifies to the importance of
creating highly complementary symbiotic pairs (plant and microorganisms), with the purpose of increasing responsiveness of
plants to inoculation.
It is necessary to realize that, without preliminary tests, the
use of preparations of bacteria can be not only ineffective, but
also can have negative results. On the other hand, the careful
selection of varieties of lupin and complementary
microsymbionts can increase efficiency of plants and fertility of
soils, and also save expenditures on mineral fertilizers.
One major condition for successful breeding of lupins with
high nitrogen-fixing ability is the availability of genetically wellinvestigated and diverse materials, both plants and microorgan-
Fig. 4. Comparative
sizes of plants of
yellow lupin cv.
‘Cyt’ from Poland
inoculated with
Bradyrhizobium
lupini (right), and
control variant (left).
isms. Until now, more attention in research has been given to
the second component of the symbiosis – nodulating bacteria.
Research on increased efficiency of nitrogen fixation is put
forward at the expense of selection of leguminous plants
(Tchetkova and Tikhonovich 1986; Kurlovich et al. 1997). Furthermore, these components of a symbiosis are not equivalent,
as the leguminous plant can exist and give good production
Table 5. Effects of nodule bacteria, biostimulator lentechnin (LT), and root diazotrops mizorin (MIZ) on activity
of nitrogenase and productivity of fodder (sweet) Lupinus polyphyllus Lindl. (average for 1990–1995).
Treatment
Activity of nitrogenase
(Mkmol C2H4 h-1 plant-1)
Yield of green mass
(kg/m²)
Mass of seeds
(g/plant)
Control
Strain 1610
Strain 1614
Strain 1625
Strain 1647
Inoculation + lentechnin (LT)
Strain 1610 + LT
Strain 1614 + LT
Strain 1625 + LT
Strain 1647 + LT
Inoculation + mizorin (MIZ)
Strain 1610 + MIZ
Strain 1614 + MIZ
Strain 1625 + MIZ
Strain 1647 + MIZ
SEM (standard error of mean)
80
172
55
336
166
50
190
30
275
1555
150
540
810
600
330
27
6.8
6.2
6.1
8.5
7.3
7.0
5.3
5.7
9.1
8.3
5.1
3.2
4.8
8.9
7.6
0.6
18.0
21.3
15.2
26.7
23.8
22.2
17.6
22.3
26.2
25.1
17.3
22.6
21.3
27.2
22.4
1.2
without microorganisms, for example with the expense of mineral fertilizers. However, it is necessary to execute genetic and
breeding research in both directions. The selected prospective
plant material should pass tests in treatments with the different
strains of nodulating bacteria, and these new strains need to be
tested on a rather large set of lupin accessions with different
ecogeographical origins. The final stage of these operations
should be the creation of effective and complementary symbioses (variety of plant and strain of bacteria), ensuring high symbiotic nitrogen-fixing ability.
It is necessary to remark that the selection of lupin was
begun long before the phenomenon of symbiotic nitrogen fixation was understood. Moreover, in those regions where wild
lupin did not grow and was introduced, the natural soil populations of microorganisms very frequently did not contain high
levels of active (and even specific) nodule bacteria. As a result,
there was an unconscious selection of genotypes with low nitrogen-fixing ability. Thus, we now have varieties of lupin that
react rather poorly to inoculation with bacteria, but are capable
of providing a certain level of efficiency without inoculation. In
this connection, one important problem now is the effective
selection of bacterial strains suitable for existing commercial
varieties of lupin, and the necessity of further selecting for a high
intensity of symbiotic nitrogen fixation.
As an example of a successful solution to this problem there
can be carried out by us selection of the effective strain of bacteria
(1625) for the perennial multifoliate fodder variety Washington
(Lupinus polyphyllus Lindl.) from America. Given the results presented here, we conclude that efficient cultivation of Washington lupin is possible with highly efficient preparations of nodule
bacteria strains, particularly in regions where lupin has not yet
been cultivated. For each new variety of lupin it is necessary to
select efficient nodule bacteria strains that correspond to the
genotype of the plant.
For creation of valuable genotypes of lupin it is necessary to
take into account also the activity of the nitrogenase complex,
which varies in the different forms of lupin from 0 to 100 Mmol
C2H4 h-1 plant-1, and more. Even among plants of one sample
there is variability of the given parameter (CV from 39.0 to
94.17%). Each sample represents a complex population consisting of plants with different levels of nitrogen-fixing activity.
Selection of prospective plants should consider their levels of
nitrogenase activity and its place in the selection process.
Matching of the data on activity of the nitrogenase complex
with parameters of accumulation of dry matter and protein
content at lupin shows that the correlation between these
parameters is frequently, though not always, significant. For
example, the variety of yellow lupin ‘Augy’ from Lithuania has
a very high nitrogenase activity (93.10 Mmol C2H4 h-1 plant-1),
and the variety ‘Cyt’ from Poland has the lowest activity (5.52
Mmol C2H4 h-1 plant-1). As a result, the total dry matter at
variety ‘Augy’ grown without N and without inoculation with
nodulating bacteria is 24.2 g/plant, and for variety ‘Cyt’ only 6
g/plant. The same varieties grown with inoculation of nodulating bacteria (strain 376A) produced 20.7 and 10.2 g/plant,
respectively. This example, except for the positive connection of
two above-stated parameters, strongly illustrates the mismatch
of strain 367A of nodule bacteria to the yellow lupin variety
‘Augy’.
Thus, only complex record-keeping of all parameters describing the intensity of biological nitrogen-fixation in lupin
allows us to evaluate the diversity in a species, to allocate
effective material for selection, and also to develop many theoretical positions useful for the introduction and classification
of a source material. In our research we were guided by Vavilov’s
differential systemogeographic method of crop studies based
on his Law of Homologous Series in hereditary variation and on
the theory of the centres of origin (domestication) of cultivated
plants (Vavilov 1920, 1935, 1987). This enabled us to not only
disclose the diversity of forms, but also to reveal a series of
regularities in their variation depending on the degree of cultivation, geographic environments and soil conditions. Our research has established that samples with high nitrogen-fixing
ability are more often material from primary centres of forma-
76
tion and origin of that or other species of lupin (Kurlovich 1988).
An example is the yellow lupin accession k-2292 from Portugal,
which is an updated centre of formation of yellow lupin (Vavilov
1935, 1987; Kurlovich et al. 1995). The high productivity of this
accession under inoculation with Bradyrhizobium sp. (Lupinus) is
confirmed not only by our data, but also by other research
(Cheremisov 1991). Among accessions of white lupin from
Greece (also a centre of origin and formation of this species) was
the sample k-2864, also with high nitrogen-fixing ability. Our
explanation for this is that the plants and their nodulating
bacteria, during evolution at the centres of formation and domestication, became adapted to one another. When cultivated
in new places, the plant did not thrive, but when inoculated
with Bradyrhizobium sp. (Lupinus) bacteria in the new locations, the
plants responded to give such high results. The indicated forms
deserve the special attention as objects of genetic research, as the
genes controlling nitrogen-fixing ability have jointly evolved
with those of symbionts (Simarov and Tikhonovich 1985).
The valuable forms of nitrogen-fixing lupins can be improved with mutagenesis (Sidorova et al. 1995). Practice shows
that the best results can be achieved for optimum combination
of mutagenesis and hybridization. For these purposes in hybridization it is necessary to involve mutants, wild and domesticated forms of lupin of various geographical origins.
The results point to some areas of research that will allow the
existing genetic resources of lupin to contribute further selection
and breeding activities. Highly productive varieties of lupin
could be created with increased abilities to nodulate and more
efficient symbiotic nitrogen fixation, in conditions of low natural contents of soil mineral N. To do this, lupin varieties better
able to form associations with the most effective strains of
bacteria will need to be located.
List of the best selected accessions of
lupin, recommended as initial material
for future breeding for high nitrogenfixing ability
White lupin (L. albus)
· Accessions ensuring an increase of a crop yield under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 363a) without application of mineral N (in comparison with control): cvs.
‘Start ‘ (k-’2644') from Russia, ‘Olezka’ (k-2980) from Ukraine
accessions, k-2989 and k-3250 from Portugal, k-2864 from
Greece, ‘El Harrach-1’ (k-3110) from Algeria.
· Accessions with high activity of nitrogenase*: Lines 802-15
(k-2623) and 48B (k-7986) from Portugal, accessions k-507 from
Egypt, ‘El Harrach-1’ (k-3110) from Egypt, k-1602 from Poland.
· Accession described by increase of nitrogenase activity under artificial processing of Bradyrhizobium sp. (Lupinus) bacteria*:
cvs. ‘Snezinka’ (k-1596) and ‘Tambovsky 86’ (k-2806) from
Russia, k-1601 from Italy and ‘Lublanc’ (k-2589) from France.
Narrow-leafed lupin (L. angustifolius)
· Accessions ensuring an increase of a crop yield (in comparison with control) under processing of Bradyrhizobium sp. (Lupinus)
bacteria (strain 367A) without application of mineral N: k-3065
from Australia, ‘Determinant-2’ (k-3365) and ‘Determinant-3’
(k-3366) from Russia, ‘Apva’ (k-2950), ‘Vika 65’ (k-2954), ‘DG94’ (k-3351) and ‘DG-95’ (k-3352) from Belarus, wild forms k3076, k-3079 from Spain, k-3083 from Portugal and k-3093 from
Morocco.
· Accessions ensuring an increase of green and dry matter
under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain
367A) also in a combination with application of mineral N*: cv.
‘Unicrop’ (k-2096), lines 75A/326 (k-3061), 75A/330 (k-3064)
from Australia, cv. ‘Melkosemianny’ (k-1354) from Latvia, ‘Mut1’ (k-2803 from Poland, accessions ‘Vada 10’ (k-2681), ‘Jniven’
(k-2953) from Belarus, ‘Nemchinovsky 846’ (k-1981), ‘Determinant 4’ (k-3367) from Russia, wild forms k-3079, k-3081, k-3082
from Spain, k-3083, k-3084, k-3087, k-3090 from Portugal, k3093, k-3094, k- 3097 from Morocco.
Yellow lupin (L. luteus)
· Accessions ensuring an increase of a crop yield under
processing of Bradyrhizobium sp. (Lupinus) bacteria (strain 375A)
without application of mineral N: cvs. ‘Sojuz’ (k-2610), ‘Foton’
(k-2649) from Ukraine, ‘T-12’ (k-2000) from Sweden, k-2869
and k-3070 from Spain, wild form k-2292 from Portugal, cv.
‘Cyt’ (k-2398) from Poland, and cv. ‘Augy’ (k-2956) from
Lithuania.
· Accessions ensuring an increase of green and dry matter
under processing of Bradyrhizobium sp. (Lupinus) bacteria (strain
375A) in a combination with application of mineral N*: cvs.
‘Sojuz’ (k-2610), ‘Foton’ (k-2649) from Ukraine, k-2869 from
Spain, wild form k-2292 from Portugal.
** These data are the result of our previous investigation and
publications in Russian (Kurlovich et al. 1995, 1997).
Acknowledgements
We wish to express our gratitude to Dr A.V. Khotyanovich of the
Institute for Agricultural Microbiology for valuable assistance
and advice during the experiments in 1988-95, and to Dr Gudni
Hardarson (FAO/IAEA Programme, Austria) for his interest,
discussion and valuable literature. This work was supported
financially by State Research Programme INTERBIOAZOT2000, Russian Fund of Fundamental Research, Grant of the
European Community (INTAS).
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78
Plant Genetic Resources Newsletter, 2000, No. 123: 68 -77
News and Notes
Established terms and definitions on plant genetic resources and biological
conservation in dispute
There is a concern that some critical conservation concepts are
inappropriately defined. An examination of the meaning of words
used in conservation shows that some convey misleading definitions, i.e. distinct terms and distinct definitions are often applied
to materials seemingly equal in nature. In particular, three select
terms and their definitions – namely ‘genetic resource’, ‘biological resource’ and ‘biodiversity’ – have been shown to carry a
number of incongruencies.1 Nonetheless, although flawed or
redundant, these concepts (in particular, biological resource and
biodiversity) are in the way of becoming established, supported
as they are by parts of the scientific community and the political
classes. The argument defended is that the establishment of
defective concepts undermines the foundations of scientific
thought itself. Seemingly, for example, the concept of biological
resource is a circumscription rather than a definition and overlaps with that of genetic resource. Likewise, the term biodiversity
sounds more like a conglomerate given the inclusion in the
definition of biotic and abiotic elements. In the interest of truth, a
wider discussion of this subject is much encouraged.
1 Allem, A.C. 1999. Dubious concepts in the Convention on Biological Diversity with special reference to genetic resource, biological
resource, and biodiversity. In Second International Symposium on Genetic Resources for Latin America and the Caribbean,
SIRGEALC 2 (A.S. Mariante and P.G. Bustamante, eds.). Brasília. Proceedings published in CD-ROM.
Book Review
Guide to Handling of Tropical and Subtropical Forest Seed
Lars Schmidt
2000. Danida Forest Seed Centre, Krogerupveg 21, DK-3050 Humlebaek, Denmark ([email protected]). ISBN 87-982428-6-5.
Available free.
Fifteen years since the issuance of “A Guide to Forest Seed
Handling, with special reference to the tropics” compiled by R.L.
Willan and published jointly by DFSC and FAO, relevant
progress has been achieved and new techniques and protocols
for effective seed handling have become available.
The present “Guide to Handling of Tropical and Subtropical
Forest Seed” is meant to provide the reader with a comprehensive and updated review of efficient methods currently available
for forest seed collection, handling and storage.
As remarked in Chapter 1, problems related to seed procurement, processing and storage often represent a tangible
restriction on the use of particular species. Scarcity of seed,
inconstancy in seed production, short viability, difficulties in
collecting and in removing barriers to germination are, among
others, factors that limit the use of many tree species. In fact
seedlings often tend to be sold at a fairly uniform price, no
matter how much effort was involved in raising them (p. 7,
quoted from Pedersen 1994). Consequently, only a handful of
important genera and families are used in planting programmes,
despite the increasing demand to broaden species diversity
and to encourage the use of native trees. The application of the
most suitable and cost-effective techniques for handling and
storage of tropical forest seeds has the potential to bring more
species into use.
This Guide draws on the well-known capacity and experience
gained by the Danida Forest Seed Centre over more than 30 years
of continuous activity in this sector, particularly with the poorly
understood tropical and subtropical species. It is written in a clear
and direct style, while complying with sound scientific quality and
providing a comprehensive list of reference at the end of each
chapter.
The outline of the book observes a logical sequence, starting
with a general introduction to seed biology (Chapter 2) and then
following the chronological order of seed handling: planning of
seed collecting (Chapter 3), description of collecting phases
(Chapter 4), processing (Chapter 6), seed storage and pretreatment (Chapters 8-9), and germination and seedling establishment
(Chapter 10).
Chapter 8 deals specifically with the effects of pests and
pathogens on seed quality and gives useful hints on how to control
them during the collecting, processing and storage phases, either
through necessary precautions or through seed treatment.
Seed testing (Chapter 11) is discussed from the perspective
of the seed handler, thus describing what is measured during
these tests, rather than how to conduct them, redirecting the
reader to existing detailed guidelines for in-depth reading.
Possible implications of seed handling on the genetic quality
of seeds are discussed in Chapter 12. The author draws the
readers’ attention to possible caveats that may occur, in this
respect, at any step in the seed-handling process. In fact, since
most of the physical, morphological and physiological characteristics of the seeds differ according to family, each handling
phase might result in a negative selection against seeds belonging to specific families rather than others. Therefore, part of
or whole families may be lost during processing and handling,
and the ratio between families in the final bulked seed lot or
plants in the nursery may be different from the ratio between
families in the seed lot before processing (p. 364, quoted from
Lauridsen 1995).
Chapter 13 provides details on the taxonomy, biology and
management, in relation to nursery operation, of important
microsymbionts for cultivated plants (e.g. mychorrizae, rhizobia
and frankiae). There are specific cases, e.g. raising seedlings on
a sterile medium or plantation on sites.
Leonardo Petri
Plant genetic
resources in
Below are some interesting Web addresses related to genetic resources. Please send information on other sites to the Managing Editor
of the Newsletter at [email protected]. The addresses given here were all operating at the time of going to press (September 2000).
Digital Taxonomy
http://www.geocities.com/RainForest/Vines/8695/
Digital Taxonomy is an attempt to present a wide-ranging resource of information for biodiversity data management in the
World Wide Web, and promote the effective use of computers for
handling biological software development projects. The site provides a range of links on software, hardware, methodologies,
standards, data sources, and projects related to biodiversity data
management, covering DELTA, taxonomic databases, ecology,
morphometrics, and phylogenetic analysis software, with emphasis on the exchange of free scientific software tools (preferably
those including source code), computer techniques, and Internet
addresses of developers and distributors of free bioinformatics
software.
The Expert Center for Taxonomic
Identification
http://www.eti.uva.nl
The Expert Center for Taxonomic Identification (ETI) is a nongovernmental organisation (NGO) in operational relations with
UNESCO. Its mission is to develop and produce scientific and
educational computer-aided information systems, to improve the
general access to, and to promote the broad use of taxonomic and
biodiversity knowledge worldwide.
ETI’s World Biodiversity Database, available on CD-ROM,
provides a combination of scientific text, expert illustrations and
professional photographs.
ETI produces about 10 CD-ROM titles a year, packed with
megabytes of reliable and thoroughly reviewed scientific information, all quickly accessible on CD-ROM. These CD-ROMs are
distributed at the lowest possible (cost) price, in order to allow
every scientist, including those in developing countries, to get
access to information.
The International Legume Database &
Information Service (ILDIS)
http://www.ildis.org/
The International Legume Database & Information Service (ILDIS)
is an international project that aims to document and catalogue
the world’s legume species diversity in a readily accessible
form. Research groups in many countries are participating on a
cooperative basis to pool information in the ILDIS World Database of Legumes, which is used to provide a worldwide information service through publications, electronic access and enquiry
services.
The ILDIS Co-ordinating Centre is based at the Centre for
Plant Diversity and Systematics, School of Plant Sciences, The
University of Reading, UK. ILDIS has regional centres in Argentina, Australia, Brazil, China, Colombia, India, Japan, Malawi,
New Zealand, Russia and USA. These centres collect information from local herbaria, national botanists and from literature
written in many different languages, making accessible a wealth
of information that would otherwise remain hidden.
Species 2000
http://www.sp2000.org/
Species 2000 aims at enumerating all known species of plants,
animals, fungi and microbes on Earth as the baseline dataset for
studies of global biodiversity. It will also provide a simple access
point enabling users to link to other data systems for all groups of
organisms, using direct species-links. Users worldwide will be
able to verify the scientific name, status and classification of any
80
known species via the Species Locator, which provides access
to species checklist data drawn from an array of participating
databases.
The goal of Species 2000 is to provide a uniform and validated quality index of names of all known species for use as a
practical tool.
New Agriculturist online
http://www.new-agri.co.uk/
New Agriculturist online provides monthly updates on the latest
news and developments in tropical agriculture for a global audience. It also provides information on training courses and conferences for agriculturists, and on recent publications.
Sections include: Points of view (children in agriculture, in
the latest issue); Perspective; Focus on . . .(beekeeping, in the
latest issue); In print; News briefs; In conference; On course;
Developments; and Country profile. Recent books on PGR reviewed include “Encouraging Diversity: The conservation and
development of plant genetic resources” (Conny Almekinders
and Walter de Boef, eds), published by Intermediate Technology
Publications, and “The Root Causes of Biodiversity Loss”
(Alexander Wood, Pamela Stedman-Edwards and Johanna
Mang, eds), published by WWF-International in association with
Earthscan.
The Internet Directory of Botany
http://www.botany.net/IDB/
This would be a useful starting point for anyone seeking botanical
information on the Internet.
The Directory is an index to botanical information available
on the Internet, compiled by Anthony R. Brach (Harvard University Herbarium, Cambridge; http://www.herbaria.harvard.edu/;
Missouri Botanical Garden, St. Louis, USA; http://www.mobot.org/
), Raino Lampinen (Botanical Museum, Finnish Museum of Natural History, University of Helsinki, Finland; http://www.helsinki.fi/
kmus/), Shunguo Liu (SHL Systemhouse, Edmonton, Canada)
and Keith McCree (Oakridge, Oregon).
Links are organised by the following categories: Arboreta and
Botanical Gardens; Botanical Societies, International Botanical
Organizations; Biologists’ Addresses; Botanical Museums, Herbaria, Natural History Museums; Checklists and Floras, Taxonomical Databases, Vegetation; Conservation and Threatened
Plants; Economic Botany, Ethnobotany; Gardening; Images;
Journals, Book, Literature Databases, Publishers; Link Collections, Resource Guides; Listservers and Newsgroups; Lower
Plants and Fungi; Other Resources; Paleobotany, Palynology,
Pollen; Software; University Departments, Other Institutes; and
Vascular Plant Families.
Plant Genetic Resources
Newsletter
Bulletin des ressources
phytogénétiques
Boletín de Recursos
Fitogenéticos
Aims and scope
Domaine d’intérêt
Objetivos y temas
The Plant Genetic Resources Newsletter publishes papers in English, French or Spanish,
dealing with the genetic resources of useful plants,
resulting from new work, historical study, review
and criticism in genetic diversity, ethnobotanical
and ecogeographical surveying, herbarium studies, collecting, characterization and evaluation,
documentation, conservation, and genebank practice.
Le Bulletin des ressources phytogénétiques publie des articles en anglais, en espagnol et en
français, sur les ressources génétiques de plantes utiles, fruit de nouvelles recherches, d’études
historiques, d’examens et de critiques concernant la diversité génétique, d’études ethnobotaniques et écogéographiques, d’études d’herbiers,
d’activités de collecte, de caractérisation et
d’évaluation, de documentation, de conservation
et les pratiques des banques de gènes.
El Noticiario de Recursos Fitogenéticos publica
documentos en inglés, francés y español que
tratan de los recursos genéticos de plantas útiles,
fruto de nuevos trabajos, estudios históricos,
revisiones y análisis críticos relacionados con la
diversidad genética, investigaciones etnobotánicas y ecogeográficas, estudios de herbarios,
actividades de colección, caracterización y evaluación, documentación, conservación, y prácticas en bancos de germoplasma.
Parrainage
Dirección
Le Bulletin des ressources phytogénétiques est
publié sous les auspices de l’Institut international
des ressources phytogénétiques (IPGRI) et de la
Division de la production végétale et de la protection des plantes de l’Organisation des Nations
Unies pour l’alimentation et l’agriculture (FAO)
El Noticiario de Recursos Fitogenéticos se publica bajo los auspicios conjuntos del Instituto Internacional de Recursos Fitogenéticos y la Dirección de Producción y Protección Vegetal de la
Organización de las Naciones Unidas para la
Agricultura y la Alimentación.
Distribution
Distribución
Le Bulletin des ressources phytogénétiques paraît
une fois par an en un volume regroupant quatre
numéros publiés en mars, juin, septembre et
décembre. Il est distribué gratuitement aux bibliothèques des banques de gènes, universités,
services gouvernementaux, instituts de recherche, etc. s’intéressant aux ressources phytogénétiques. Il est aussi envoyé sur demande à tous
ceux pouvant démontrer qu’ils ont besoin d’un
exemplaire personnel de cette publication.
El Noticiario de Recursos Fitogenéticos aparece
como un volumen anual compuesto por cuatro
números, que se publican en marzo, junio, septiembre y diciembre. Se distribuye gratuitamente a
las bibliotecas de bancos de germoplasma, facultades universitarias y servicios gubernamentales,
centros de investigación, etc. que se interesan
en los recursos fitogenéticos. También pueden
obtener este noticiario las personas que demuestren necesitar una copia personal.
Articles
Types de documents publiés
Tipos de documentos
An article will publish the results of new and
original work that makes a significant contribution to the knowledge of the subject area that the
article deals with. Articles, which should be of a
reasonable length, will be considered by the Editorial Committee for scope and suitability, then
assessed by an expert referee for scientific content and validity.
Articles
Artículos
Un article contient les résultats de travaux nouveaux et originaux qui apportent une contribution
importante à la connaissance du sujet dont traite
l’article. Les articles, qui doivent être d’une
longueur raisonnable, sont d’abord examinés par
le Comité de rédaction qui en évalue la portée et
la validité, puis par un expert qui en examine le
contenu et l’intérêt scientifiques.
Los artículos divulgarán los resultados de trabajos nuevos y originales que contribuyan de modo
importante al conocimiento del tema tratado.
Dichos artículos, que deberán tener una longitud
razonable, serán examinados por el Comité de
Redacción en cuanto a su pertinencia e idoneidad
y posteriormente un experto juzgará su contenido
y validez científicos.
A short communication will report results, in an
abbreviated form, of work of interest to the plant
genetic resources community. Short communications in particular will contain accounts of germplasm acquisition missions. The papers will be
assessed by an expert referee for scientific content and validity.
Brèves communications
Comunicaciones breves
On entend par brève communication un texte
contenant, sous une forme abrégée, les résultats
de travaux présentant un intêrêt pour tous ceux
qui s’occupent de ressources phytogénétiques.
Elle contient en particulier des comptes rendus
des missions d’acquisition de matériel génétique.
Las comunicaciones breves informarán de modo
conciso sobre los resultados de trabajos de interés para las personas que se ocupan de los
recursos fitogenéticos. Las comunicaciones
breves incluirán, en particular, resúmenes sobre
las misiones de adquisición de germoplasma.
Other papers
Autres documents
Otros documentos
The Plant Genetic Resources Newsletter will
publish other forms of reports such as discussion
papers, critical reviews, and papers discussing
current issues within plant genetic resources.
Book reviews will be printed, as well as a News
and Notes section. Suggestions for books to
review are invited, as are contributions to News
and Notes.
Le Bulletin des ressources phytogénétiques publie d’autres types de rapport tels que des documents de synthèse, des études critiques et des
articles commentant des problèmes actuels concernant les ressources phytogénétiques. Le Bulletin publie une revue de livres ainsi qu’une section intitulée Nouvelles et Notes. Les auteurs
sont invités à envoyer leurs suggestions pour les
livres à passer en revue ainsi que des contributions aux Nouvelles et Notes.
El Noticiario de Recursos Fitogenéticos publicará otros tipos de informes, como documentos
de trabajo, análisis críticos, y documentos que
examinen cuestiones de actualidad relacionadas
con los recursos fitogenéticos. El Noticiario publicará una reseña de libros así como una sección
de Noticias y Notas. Las propuestas de libros
para reseñar y las contribuciones a la sección de
Noticias y Notas serán bien acogidas.
Présentation
Los documentos deben entregarse, incialmente,
en forma de texto mecanografiado o a través del
correo electrónico. La versión final debe presentarse como un archivo de correo electrónico o en
disquete compatible con el sistema operativo
Windows. Los manuscritos para publicar y otras
comunicaciones sobre asuntos relativos a la redacción deberán dirigirse a la Oficina de Redacción del IPGRI.
Management
The Plant Genetic Resources Newsletter is published under the joint auspices of the International Plant Genetic Resources Institute (IPGRI) and
the Plant Production and Protection Division of
the Food and Agriculture Organization of the
United Nations (FAO).
Availability
The Plant Genetic Resources Newsletter appears as one volume per year, made up of four
issues, published in March, June, September and
December. Plant Genetic Resources Newsletter
is available free of charge to interested libraries
of genebanks, university and government departments, research institutions, etc. The periodical
may also be made available to individuals who
can show that they have a need for a personal
copy of the publication.
Types of paper
Short communications
Submission
In the first instance papers may be submitted in
typescript form or as an Email message. The
final version may be submitted as an Email file or
as a Windows-readable file on diskette. Manuscripts submitted for publication and other communications on editorial matters should be addressed to IPGRI's Editorial and Publications
Unit.
En premier lieu, les documents doivent être soumis dactylographiés ou par courrier électronique.
La version définitive doit être présentée en fichier
de courrier électronique ou sur disquettes compatibles Windows. Prière d’adresser les manuscrits
présentés pour être publiés et d’autres communications sur des questions de rédaction au Bureau
de rédaction de l'IPGRI.
Presentación
No. 123, September 2000
Contents
Articles
Utilization of germplasm conserved in Chinese national genebanks - a survey
G. Weidong, J. Fang, D. Zheng, Y. Li, X. Lu (China), R.V. Rao (Malaysia), T. Hodgkin (Italy)
and Z. Zongwen (China) .......................................................................................................................................... 1
The use of home gardens as a component of the national strategy for the in situ conservation of
plant genetic resources in Cuba
L. Castiñeiras, Z.F. Mayor, S. Pico and E. Salinas (Cuba) ................................................................................... 9
Ethnobotanical testimony on the ancestors of cassava (Manihot esculenta Crantz subsp. esculenta)
A.C. Allem (Brazil) ................................................................................................................................................ 19
Reincorporación del fríjol carauta (Phaseolus lunatus L.) a la agricultura tradicional en el resguardo
indígena de San Andrés de Sotavento (Córdoba, Colombia)
G.P. Ballesteros, A.G. Torres y M. Barrera (Colombia) ...................................................................................... 23
El conocimiento local y su contribución al trabajo de rescate, conservación y uso de las semillas
de Phaseolus y Vigna en las vegas del Río Orinoco, Estado Guárico, Venezuela
A. Bolivar, M. Lopez, M. D'Goveia y M. Gutiérrez (Venezuela) .......................................................................... 28
A network for the management of genetic resources of maize populations in France
J. Dallard, P. Noël, B. Gouesnard and A. Boyat (France) ................................................................................... 35
Caracterización por cianogénesis de una colección de trébol blanco (Trifolium repens L.) en
Pergamino, Argentina
E.M. Pagano y B.S. Rosso (Argentina) ............................................................................................................... 41
Conservation et valorisation des ressources génétiques fourragères et pastorales du Nord Tunisien
M. Chakroun et M. Zouaghi (Tunisia) ................................................................................................................... 46
Resistance to powdery mildew in barley (Hordeum vulgare L.) landraces from Egypt
J.H. Czembor (Poland) ......................................................................................................................................... 52
Genotypic variation of Kenyan tomato (Lycopersicon esculentum L.) germplasm
S.G. Agong (Kenya), S. Schittenhelm and W. Friedt (Germany) ........................................................................ 61
Evaluation of the biological nitrogen-fixing ability of lupin (Lupinus L.)
B.S. Kurlovich, L.T. Kartuzova, B.M. Cheremisov, T.A. Emeljanenko, I.A. Tikhonovich,
A.P. Kozhemyakov and S.A. Tchetkova (Russia) .................................................................................... 68
News and Notes ................................................................................................................................................... 78
Book Review ........................................................................................................................................................ 78
Cyberspace .......................................................................................................................................................... 79

Plant Genetic Resources newsletter

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