Glycine Genetic Resources
Vaughan Duncan 1, Norihiko Tomooka, Akito Kaga, Takehisa Isemura
and Yosuke Kuroda
National Institute of Agrobiological Sciences ,Tsukuba, Japan
1

Currently FAO Regional Office for Asia and the Pacific , 39 Phra Athit Road, Bangkok 10200, Thailand

A. The Soybean Phenomena
The very recent history of the ancient crop thesoybean has been quite remarkable. It took several
thousand years for soybean to reach a global production of about 27 million metric tons that was 1961.
That production doubled in the following twelve
years. By 2005 world soybean harvest was 214 million metric tons or about 8 times what it was 40 years
earlier.
Soybean has become the dominant legume
feeding the global population and the story of its history in the New World is illustrative of how rapidly
agriculture can change. Between 1929 and 1939 soybean production increased by 970% due to a combination of factors but particularly the development of
the soybean processing industry. The rise of soybean
production in Brazil is equally remarkable and fastwith Brazil’s share of global soybean production rising from 1% in 1961 to 10% in 1973.
While the recent history of soybean has been
dominated by events in the New World it is the Far
East that is the home of soybean and its single closewild relative G. soja . The genus Glycine is split into
two subgenera, subgenus Glycine and subgenus Soja.
Subgenus Glycine consists of 26 perennial species
mainly found in or near Australia. Subgenus Soja
consists of the East Asian wild annual species G. soja
and cultivated soybean, G. max .
In this paper we will briefly discuss the wild
genetic resources of Glycine and their diversity andpotential in crop improvement.
B. The Place of Soybean among other domesticated legumes
The genus Glycine consists of species withchromosome numbers of 2n=2x=40 or multiples
thereof. One species, G. tomentella consists of acomplex of cytotypes including various stable aneuploids with chromosome numbers of 38 or 78. The
phylogenetically close relatives of Glycine such as
Vigna and Phaseolus have chromosome numbers of
11 or rarely multiples thereof. Glycine is a model
genus for studying ancient polyploidy (Doyle et al .
2004).

Glycine is phylogenetically closely related toa large number of important domesticated legumes
including common bean (Phaseolus 2n=2x=22),
cowpea and mungbean (Vigna 2n=2x=22), pigeonpea (Cajanus 2n=2x=22) and winged bean (Phosocarpus 2n=2x=18) (Fig. 1).
C. The Genepools of the Soybean
The genepools of soybean are shown (Fig. 2).
It has proved extremely difficult to make successful
hybrids using conventional techniques between thetwo subgenera, subgenus Soja and subgenus Glycine .
To achieve gene transfer between these two subgenera radical techniques need to be used. To date only
three of the 26 wild perennial species of Glycine
have been hybridized with soybean, G. argyrea Tindale, G. canescens F.J. Hermann and G. tomentella
Hayata.
D. The subgenus Glycine
In 1977 six perennial wild Glycine were recognized (Broué et al . 1977) but since that time there
has been extensive exploration and biosystematicstudies and currently 26 perennial Glycine species
are recognized, many of then with highly restricteddistribution in Australia. In Japan two perennial
wild Glycine are found in highly restricted parts of
Okinawa, G. tabacina (Labill.) Benth and G. koidzumii (Ohwi). G. tabacina is only known from a small
islands of Ie (Okinawa) and Okinoerabu (Kagoshima)
and G. koidzumii is only known from on the small
islands of Miyako and Ishigaki (Okinawa).
Polyploidy
G. tabacina and G. tomentella have beenstudied in relation to their polyploidy origins. G. tabacina consists of two types of tetraploid that havedifferent origins. One type which has adventitious
roots (2n=80) (WAR) and another without (NAR).
The former (WAR) is a segmental allopolyploid
while the later (NAR) is a true allopolyploid (Singhet al . 2006). G. tomentella consists of 4 morphologically indistinguishable cytotypes 2n=38, 40, 78 and
80. Among these cytotypes there are three groupsof aneutetraploids and three groups of tetraploids.
Various studies suggest that these groups result from-1-

multiple independent allopolyploid events (Doyle et
al ., 2004; Singh et al . 2006).
Uses
The perennial wild Glycine harbor manypotentially useful genes among them resistance tosoybean rust (Phackopsora pachyrhizi Sydow) andsoybean cyst nematode (SCN) (Heterodera glycines
Ichinohe) (Singh and Hymowitz, 1999). To date there
is only one report of fertile backcross derived progenies between soybean and wild perennial soybean,
Glycine tomentella (2n=78) (Singh et al ., 1998). Introgression of SCN resistance was reported in lines
derived from this cross (Riggs et al . 1988).
To fully exploit useful genes from perennial
wild Glycine in soybean breeding new approaches
are needed.
E. The subgenus Soja
Japan is a center of diversity for soybean andwild soybean (Glycine soja Sieb. & Zucc.). Overthe past decade while collecting wild Vigna acrossJapan our laboratory also collected sympatric wild
soybeans. The wild soybeans collected have become
the basis for our studies of wild soybean diversity
in Japan and beyond. In addition, our group has
also undertaken large scale search for evidence ofgene flow from cultivated to wild soybeans and subsequent monitoring of sites where this was found.
Hundreds of hours have been spent searching, in themost likely areas of Japan, for clear evidence of soybean/wild soybean hybrids. These have been foundmainly in Saga prefecture on the southern main island of Japan, Kyushu, where soybeans are widelygrown and sympatric with wild soybeans. The recordof the search for wild soybean/soybean hybrids canbe found in the trip reports given in Appendix 1 authored by A. Kaga and Y. Kuroda. The rest of thispaper will discuss the results of studies lead by Drs.
Akito Kaga and Yosuke Kuroda.
(a) Wild soybean core collection (Kuroda et al .
2009)
SSR (microsatellite) markers were used toanalyze a large collection of wild soybean accessions(1305) from across its area of distribution and Japanese cultivated soybeans. The results of the study
revealed:
i. SSR allelic diversity could be clustered into 53
groups that largely corresponded with different geographic locations. This supports the view from otherstudies that wild soybeans are largely differentiatedbased on geography, suggesting long distance dispersal is uncommon.
ii. Average alleles per locus for wild soybeans (about
28 alleles/locus) were much higher than for Japanese-2-cultivated soybean (about 5 alleles per locus)iii. Allelic variation in Japanese wild and cultivatedsoybeans was similar supporting the view that soybean may have been separately domesticated in Japan.
iv. Russian germplasm showed a high level of allelicdiversity that may reflect waves of introductions ofwild soybean into Russia from China.
v. A high proportion of rare alleles were found in Korean wild germplasm and may reflect introductions
from China and Japan and local evolution in isolated
valley’s in Korea.
This study provided information on which toselect accessions for a core and mini core collection.
The core collection consists of 192 accessions (14%of accessions) with 97% of the allelic diversity of thewhole collection. The mini core collection consistedof 53% of accessions (5% of the whole collection)with 62.4% of the allelic diversity of the whole collection (Table 1).
(b) Population genetic structure of wild soybean
across Japan (Kuroda et al . 2006)
The second study involved analysis of the
population genetic structure of 77 wild soybean
populations from across Japan based on 8 individuals each. The populations all showed low level ofobserved heterozygosity, low out-crossing rate (mean3.4%) and strong genetic differentiation among populations. There was evidence of rare long distancedispersal over 10km and also populations within aradius of 100 kilometers showed a close genetic relationship to one another.
The genetic variation in wild soybeans wascompared with Japanese cultivated soybeans and thatrevealed that the primary factor of genetic differentiation was the difference associated with domestication and the secondary factor was geographic differentiation.
Admixture analysis revealed that 6.8% of
individuals appeared to show introgression from cultivated soybeans. These results indicated that population genetic structure of Japanese wild soybeans is(i) strongly affected by the founder effect due to seeddispersal and inbreeding strategy (ii) generally wild
soybean is well differentiated from cultivated soybean, but (iii) introgression from cultivated soybean
does occur.
(c) Fine scale genetic structure of wild soybean in
selected parts of Japan (Kuroda et al. 2008)
To further understand the genetic structure ofwild soybean 14 populations from different parts ofJapan, northern, central and southern,were studied. 7of these populations were adjacent to soybean fields

Fig. 1. The Phylogenetic position of Glycine (modified from Gepts et al .,2005)

Fig. 2. The genepools of the soybean-3-Table 1. Composition of two core sets of germplasm (from Kuroda et al .2009)
Populations

N

Core53
China
Russia
Korea
Japan
Max

53

Core192
China
Russia
Korea
Japan
Max

192

A
7
7
9
29
1

34
32
56
65
5

353

101
104
133
271
20

549

262
219
358
348
44

allele cover(%)/total/region
62.4
27.7
28.6
36.5
74.5
5.5
97.0

72.0
68.0
77.5
85.9
40.4

N (number of samples), A (number of alleles)and seven were more than 60m distant from soybean
fields i.e. further than distance of pollen flow in soybeans. SRR analysis of individuals in these populations revealed no evidence of pollen from soybean
to wild soybean. However, in populations of G.soja
outcrossing rate ranged from 0-6.3% (average 2.2%)
and the dispersal distance of pollen ranged from
5-25m (average 10.5m). In addition, 13 individualsof G. soja (7.7%) collected in four populations wereassigned to neighboring populations (100-400m).
The results suggest the occurrence of long-distancedispersal in G. soja .
Uses of G. soja
The actual use of G. soja in soybean breeding has been limited despite it having a much higher
level of genetic variation than cultivated soybean andthese being no barrier to hybrid formation. G. soja
has been used a source of high protein and productivity (Hartwig 1973). Several small seeded cultivarsof soybean have been developed for bean sprouts andnatto using G. soja as non-recurrent parent (Carter et
al . 1995; Fehr et al . 1990 a, b).
F. Concluding remarks
Despite the primary genepool of soybean being restricted to two species and secondary genepool
being absent, cultivated soybean has become one of
the world’s most important crops. The large scalecultivation of soybean means it is vulnerable to pests
and disease. Innovative breeding to tap the diverse
sources of useful genes in the tertiary genepool ofsoybean are needed to strengthen the genetic basis ofsoybean.

-4-

References cited
Carter et al . 1995. Registration of ‘Pearl’ soybean.
Crop Sci. 35:1713
Fehr W.R. et al . 1990a. Registration of ‘SS201’
soybean. Crop Sci. 30:1361
Fehr W.R. et al . 1990b. Registration of ‘SS202’
soybean. Crop Sci. 30:1361
Doyle, J.J., J. L. Doyle, J. T. Rauscher and
A.D.H.Brown. 2004. Evolution of the perennial
soybean polyploidy complex (Glycine subgenus
Glycine ): a study of contrasts. Biological Journalof the Linnean Society 82: 583-597
Paul Gepts*, William D. Beavis, E. Charles Brummer, Randy C. Shoemaker, H. Thomas Stalker,
Norman F. Weeden, and Nevin D. Young 2005.
Legumes as a Model Plant Family. Plant Physiology, Vol. 137, pp. 1228-1235.
Hartwig, E.E. 1973. Varietal development. In Soybeans: Improvement, production and Uses. American Society of Agronomy Publication 16. B.E.
Caldwell (ed.) American Society of Agronomy,
Madison, WI, pp. 187-210
Kuroda, Y., N. Tomooka, A. Kaga, S.M.S.W. Wanigadeva and D.A. Vaughan. 2009 Genetic diversityof wild soybean (Glycine soja Sieb. et Zucc.) andJapanese cultivated soybeans [G. max (L.) Merr.]
based on microsatellite (SSR) analysis and theselection of a core collection. Genetic Resources
and Crop Evolution (on-line)
Kuroda, Y., A. Kaga, N. Tomooka and D.A.Vaughan.
2006. Population structure of Japanese wild soybean (Glycine soja ) based on microsatellite variation. Molecular Ecology 15:959-974

Kuroda, Y., A. Kaga, N. Tomooka and D.A.Vaughan.
2006. Gene flow and genetic structure of wild soybean (Glycine soja ) in Japan. Crop Science 48:10711079
Riggs, R.D. et al. 1998. Possible transfer of resistance to
Heterodera glycines from Glycine tomentella to Glycine max . J. Nematol. 30:547-552.
Shurtleff, W. and A. Aoyagi nd. A special report on
history of soybean production and trade around theworld. (online at http://www.soyinfocenter.com/HSS/
history.php )Singh, R.J., K.P. Kollipara and T. Hymowitz. 1998.
Monosomic alien addition lines derived from Glycinemax (L.) Merr., and G. tomentella Hayata: production, characterization and breeding behavior. Crop
Sci. 38: 1483-1489.
Singh, R.J. and T. Hymowitz. 1999. Soybean genetic resources and crop improvement. Genome 42:605-616
Singh, R.J., R.L. Nelson and G. Chung. 2006. Soybean[Glycine max (L.) Merr.] in “Genetic Resources,
chromosome engineering and crop improvement” R.J.
Singh (editor)-5-

Appendix 1. MAFF Domestic Exploration Trips for Glycine and Vigna species from 1997 to 2008.
Trip reports listed in References can be downloaded from NIAS genebank web page at
http://www.gene.affrc.go.jp/publications.php#plant_report (each report can be found in Annual report on Exploration andIntroduction of Plant Genetic Resources, NIAS)
Most of the reports are written in Japanese with English Summary, Tables and Figures.
Year
1997

Area
Mie & Nara

1997

Yamagata

1997
1997

ShimaneFukushima, Miyagi,
Iwate, Aomori

1997

NaganoGifu, Shiga,
Kyoto,Tottori,
Hyogo,Fukui,
Ishikawa,
ToyamaNiigata
Hyogo,Okayama
Nara,
Wakayama,
Mie

1997

1997
1998
1998

1998

1998

1998

1998

1999
1999

1999

Tochigi,
Ibaraki,Chiba
Wakaykama,
Nara,Mie
Yamanashi,
Tochigi
IbarakiShiga
Okayama,
Shimane,
Yamaguchi,
Fukuoka,
Saga,
NagasakiFukuoka,
Kumamoto,
Oita,
Kagoshima,
Miyazaki
Yamaguchi,
Hiroshima,
Okayama,Aichi,
Shizuoka
Ehime, Kouchi

Ooita,
Kumamoto,
MiyazakiOkinawa(Ishigaki,
Iriomote)
Tottori,
OkayamaSpecies
Glycine max
Vigna angularis var. angularis
Vigna umbellata
Glycine max
Glycine soja
Vigna angularis var. nipponensis
Vigna angularis var. nipponensis
Glycine soja
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Glycine soja
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis (wild - weedy complex)
Vigna angularis var. nipponensis

No.
26
10
3
2
94
5
1
10
2
5
16
4
8
4
9

References
Nakayama & Katsuta (S), 1998

Glycine soja
Glycine max
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis (wild - weedy complex)
Vigna angularis var. nipponensis
Glycine soja
Vigna angularis (wild - weedy complex)
Vigna angularis var. nipponensis
Glycine max
Vigna angularis var. angularis
Vigna unguiculata
Glycine soja
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Glycine soja
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Vigna nakashimae

12
3
2
4
1
13
5
1
3
26
15
2
3
4
4
6
6
2
4
10
1

Tomooka et al., 1998

Glycine soja
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Vigna unguiculata (escaped)
Vigna unguiculata (cultivated)
Glycine soja
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Vigna umbellata
Glycine soja
Vigna angularis var. angularis
Vigna angularis var. nipponensis
Vigna unguiculata
Glycine max
Vigna angularis var. angularis
Vigna unguiculata
Vigna luteola
Vigna marina
Vigna reflexo-pilosa
Vigna riukiuensis
Vigna angularis (weedy)
Vigna angularis (wild - weedy complex)
Vigna angularis var. nipponensis

14
4
1
10
4
3
9
1
1
3
1
14
1
9
2
10
17
1
3
5
8
5
1
5
7

Vaughan et al., 1999

-6-

Kikuchi et al., 1998
Nakanishi et al., 1998
Tomooka et al., 1998
Tomooka et al., 1998

Tomooka et al., 1998
Nakayama et al., 1999
Tomooka et al., 1999

Tomooka et al., 1999

Vaughan et al., 1999

Vaughan et al., 1999

Nakayama & Miura, 2000
Tomooka et al., 2000

Vaughan et al., 2000

Appendix 1.
1999

Okinawa(MiyakoYaeyama)

2000

Fukushima

2001

Niigata(Sado)
Niigata &Yamagata
Nagano

2001
2001
2001

Okinawa(Aguni,Iheya,
Tokashiki,
Ie)

2002

Aichi, Gifu

2002

Chiba

2003

Ishikawa,
Toyama2003

Akita, Iwate

2004

Tokushima, Kouchi

2004

Hiroshima, Akita

2004

Akita,
Ibaraki,Aichi, Hiroshima,
Saga

2005

Akita,
Ibaraki,Kouchi,
Saga

2006
2006

Kouchi
Akita, Hyogo, Saga

2007

Shizuoka, Akita,
Nagano, Fukushima,
Chiba,Tochigi, Ibaraki
Yamagata,
Tottori,
Hyogo,
Kyoto, Saga,
Fukuoka,
Ooita
Shiga

2007

2008

Glycine max
Glycine koidzumii
Vigna luteola
Vigna marina
Vigna reflexo-pilosa
Vigna riukiuensis
Vigna unguiculata (escaped)
Glycine max
Vigna angularis var. angularis
Glycine max
Vigna angularis var. angularis
Glycine max
Vigna angularis var. angularis
Glycine soja
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Glycine tabacina
Vigna luteola
Vigna marina
Vigna radiata
Vigna reflexo-pilosa
Vigna riukiuensis
Vigna unguiculata
Glycine max
Vigna angularis var. angularis
Glycine max
Glycine soja
Glycine max
Glycine soja
Vigna angularis var. angularis
Vigna sp.
Glycine soja
Vigna angularis var. angularis
Glycine max
Glycine soja
Vigna angularis var. nipponensis
Glycine max
Glycine soja
Vigna angularis var. angularis
Vigna angularis var. nipponensis
Glycine soja
Glycine soja (weedy)
Vigna angularis (wild or weedy complex)
Vigna raidata (weedy)
Vigna umbellata (weedy)
Vigna unguiculata (weedy)
Glycine max
Glycine soja
Vigna angularis var. angularis (escape)Vigna angularis var. nipponensis
Vigna radiata var. radiata (escape)Vigna umbellata (escape)Vigna unguiculata (escape)Glycine soja
Glycine max
Glycine soja
Vigna angularis var. nipponensis
Vigna unguiculata (escape)Glycine soja
Vigna angularis var. nipponensis

1
5
2
17
10
27
5
26
14
20
10
35
12
13
2
10
1
1
8
1
3
4
4
12
5
3
48
9
2
5
4
80
2
1
35
3
5
31
1
2
86
19
12
1
1
1
12
51
13
16
2
5
2
37
3
44
26
1
53
7

Kaga et al., 2000

Glycine max
Glycine soja
Vigna angularis var. angularis
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Vigna unguiculata
Glycine max

2
28
7
7
15
1
9

Tomooka et al., 2008

-7-

Nagamine et al., 2001
Fukuoka et al., 2002
Ishii et al., 2002
Dharmadasa Weerasekera et al., 2002
Kalubowila et al., 2003

Ebana & Ishii 2003
Hajika et al., 2003
Kojima & Kawase, 2004

Kono et al., 2004
Kikuchi et al., 2005
Kaga et al., 2005

Kuroda et al., 2005

Kuroda et al., 2006

Saruta et al., 2007
Kuroda et al., 2007

Yamada et al., 2008

Okuizumi et al, 2008

Appendix 2. MAFF Overseas Exploration Trips for Glycine and Vigna species from 1999 to 2008.
"Trip reports listed in References can be downloaded from NIAS genebank web page at
http://www.gene.affrc.go.jp/publications.php#plant_report (each report can be found in Annual report on Exploration
and Introduction of Plant Genetic Resources, NIAS)
Some reports are written in Japanese with English Summary, Tables and Figures.
Others are written in English with Japanese Summary."					Coll. Year
1999
1999

2000

2000

2001

2002

2002
2002

2003
2004

2004

2004

Country
GreeceThailandSpeciesVigna unguiculata
Vigna exilis
Vigna grandiflora
Vigna hirtella
Vigna minima
Vigna trinervia
Vigna umbellata
Vigna unguiculata
Sri Lanka
Vigna aridicola
Vigna stipulacea
Vigna trilobata
Vigna trinervia
VietnamGlycine max
Vigna angularis var. angularis
Vigna radiata
Vigna umbellata
Vigna unguiculata
Sri Lanka
Vigna aridicola
Vigna dalzelliana
Vigna radiata var. sublobata
Vigna stipulacea
Vigna trilobata
Vigna trinervia
MyanmarGlycine max
Vigna mungo
Vigna radiata
Vigna umbellata
Vigna unguiculata
MyanmarVigna mungo
MyanmarGlycine max
Vigna angularis (weedy)
Vigna angularis var. nipponensis
Vigna hirtella
Vigna mungo
Vigna mungo var. silvestris
Vigna radiata
Vigna radiata var. sublobata
Vigna stipulacea
Vigna tenuicalulis
Vigna trilobata
Vigna trinervia
Vigna umbellata
Vigna umbellata (escape)Vigna umbellata (wild)
Vigna unguiculata
VietnamGlycine max
Vigna angularis var. angularis
MyanmarVigna stipulacea
Vigna tenuicalulis
Vigna sp.
Papua
Glycine tomentella
New Guinea
Vigna marina
Vigna radiata var. sublobata
Vigna reflexo-pilosa
Vigna unguiculata (wild )Chinana (Yunan) Glycine max& LaosVigna angularis var. angularis
Vigna hirtella
Vigna minima
Vigna reflexo-pilosa
Vigna tenuicaulis
Vigna umbellata
Vigna unguiculata

-8-

No.
3
14
1
3
9
3
31
1
2
2
7
4
30
2
12
5
16
12
3
1
2
15
4
41
5
5
19
20
1
6
1
7
7
3
1
8
4
5
21
1
1
10
1
1
8
32
19
1
1
3
3
1
14
5
1
5
2
10
4
1
2
20
4

References
Hida et al., 2000
Tomooka et al., 2000

Tomooka et al., 2000

Shimada et al., 2001

Tomooka et al., 2003

Takahashi et al., 2002

Nakagawa et al., 2002
Tomooka et al., 2003

Shimada et al., 2005
Uga et al., 2005

Tomooka et al., 2005

Tomooka et al, 2005

Appendix 2.
2005

2005

2005

2005

2005

2006

2006

2006

2007

2007
2008

Vigna hirtella
Vigna minima
Vigna reflexo-pilosa
Vigna umbellata
Vigna unguiculata (escape)Papua New
Vigna luteola
GuineaVigna marina
Vigna cf. minima
Vigna radiata var. sublobata
Vigna reflexo-pilosa
MyanmarVigna angularis var. nipponensis
Vigna hirtella
Vigna unguiculata (wild)
East Timor
Glycine max
Glycine sp.
Vigna radiata
Vigna radiata var. sublobata
Vigna reflexo-pilosa
Vigna trinervia
Vigna umbellata
Vigna umbellata (wild)
Vigna unguiculata
Laos
Glycine max
Vigna angularis var. nipponensis
Vigna hirtella
Vigna mimina
Vigna mungo
Vigna radiata
Vigna reflexo-pilosa
Vigna tenuicalulis
Vigna trinervia
Vigna umbellata
Vigna umbellata (wild)
Vigna unguiculata
Papua New
Vigna luteola
GuineaVigna cf. minima
Vigna radiata var. sublobata
Vigna reflexo-pilosa
Vigna vexillata
MyanmarGlycine max
Vigna angularis var. nipponensis
Vigna umbellata
Vigna unguiculata
Laos
Vigna minima
Vigna radiata
Vigna unguiculata
BhutanGlycine max
Vigna angularis
Vigna angularis var. nipponensis
Vigna mungo
Vigna radiata
Vigna radiata var. sublobata
Vigna umbellata
Vigna unguiculata
Vigna vexillata
Tamil Nadu, India Vigna trilobata
Tamil Nadu, India Vigna aconitifolia (cult.)
Vigna hainiana
Vigna mungo
Vigna mungo var. silvestris
Vigna radiata
Vigna radiata var. sublobata
Vigna stipulacea (cult.)
Vigna stipulacea
Vigna trilobata
Vigna unguiculata
Vigna vexillata
unidentified wild legume species
Laos

-9-

7
5
1
5
1
1
1
2
10
7
2
1
1
4
1
2
1
1
3
19
8
5
5
3
6
3
1
5
1
4
4
10
10
7
4
5
2
4
3
1
2
6
6
9
1
6
4
3
4
5
1
11
2
3
3
1
2
1
1
1
1
1
2
1
1
3
3
1

Tomooka et al., 2004

Vaughan et al., 2006

Uga et al., 2006

Tomooka et al., 2006

Tomooka et al., 2006

Vaughan et al., 2007

Watanabe et al., 2007

Tomooka et al., 2007

Tomooka et al., 2008

Fukui et al., 2008
Tomooka et al., 2008