Vigna radiata (L.) Wilczek

[Mungbean, Green gram]

To Japanese version

<The situation in Japan and information from the NIAS genebank>

Mungbean is considered to have been introduced into Japan from China before 17th century (Hoshikawa 1981). The seed materials found from "Torihama shell midden" (Fukui prefecture) were identified as mungean seeds and bottle gourd (Lagenaria siceraria) seeds (Maeda 1987). If this identification of the seed materials is correct, mungbean have been introduced in the early time of Joumon period (some 4,000 B.C). Mungbean is called "Yaenari", "Fundou", "Ao mami" or "Ryokutou". Mungbean had been cultivated widely in western and southern parts of Japan. In the middle of Showa period (1949-1960), production area of mungbean ranged 200-220 ha, and some 210 MT was produced (Hoshikawa 1981). Recently, cultivation of this crop has nearly disappeared in Japan.

We have collected a few mungbean landraces in the Nansei Archipelago (the southernmost islands) (Katsuta and Takeya 1992, Tomooka et al.1994). It is used to make "Moyashi" (a bean sprout or eaten mixed with steamed rice. In Tanegashima island, the southernmost part of Japan, a long mungbean bean sprout has been made to offer to their ancestor at the occasion of "bon festival (an important Buddhism celebration day)" (Tomooka et al.1994). In 1994, a total of 53,039 MT of mungbean was imported mainly from China (31,073 MT), Thailand (12,510 MT) and Myanmar (8,8000 MT) (Zatsumame Yunyu Kikin Kyokai.1995).

<Origin and dissemination>

Mungbean has been considered to have been domesticated in India (Vavilov 1926). His theory has been supported by other authors based on the morphological diversity (Singh et al. 1974), existence of wild and weedy types (Chandel 1984, Paroda and Thomas 1988), and archaeological remains (Jain and Mehra 1980) of mungbean in India. Wild forms of mungbean, V.radiata var.sublobata show a wide area of distribution, stretching from Central and East Africa, Madagascar, through Asia, New Guinea, to North and East Australia (Tateishi 1996).

Tomooka et al. (1992) examined the variations of seed proteins in mungbean landraces from Asia, and proposed the regions of protein type diversity and two dissemination pathways in mungbean. According to their study, the region of protein type diversity is found in West Asia (Afghanistan-Iran-Iraq area) rather than in India. Judging from the geographical distribution of protein types, mungbean may have spread mainly to the east by two routes. One route is from India to Southeast Asia; strains consisting of a few protein types with prominent protein type 1 were disseminated by this route. Another dissemination pathway may have been the route known as the Silk Road. By this route, protein type 7 and 8 strains spread from West Asia or India to China and Taiwan via the Silk Road, not by the route from Southeast Asia.

<Taxonomy>

Mungbean is an annual food legume belonging to the subgenus Ceratotropis in the genus Vigna. The genus Vigna, together with the closely related genus Phaseolus, forms a complex taxonomic group, so called Phaseolus-Vigna complex. Verdcourt (1970) proposed a very restricted concept of Phaseolus, limiting it exclusively to those American species with a tightly coiled style and pollen grains lacking course reticulation, hence, promoting significantly the concept of Vigna. According to his proposal, mungbean and its relatives (which is now recognized as the subgenus Ceratotropis) were transferred to the genus Vigna from the genus Phaseolus.

Marechal et al. (1978) followed Verdcourt and presented a monograph on the Phaseolus-Vigna complex. Their taxonomic system is generally accepted now. Three botanical varieties were recognized in their monograph. V.radiata var.radiata is cultivated form (mungbean), var.sublobata is the wild ancestral form of mungbean, and var.setulosa is also wild form which distribute in India, Indonesia, southern China. 2n=22.

<Characteristics>

Mungbean is an erect or sub-erect herb, 0.5-1.3m tall (Purseglove 1974). Flower is pale yellow. The seed color exhibits a wide range of variations from yellow, greenish yellow, light green, shiny green, dark green, dull green, black, brown, and green mottled with black. Pod color is either black, brown or pale gray when mature. 100 seeds weight is 3-7g.

Tomooka et al.(1991,1992) and Tomooka (1991) revealed the geographical distribution of growth types, seed characters and protein types in mungbean landraces collected from throughout Asia. In the South and West Asia, mungbean strains characterized by small seeds with various seed color including black, brown and green mottled with black, which show diverse growth habit and protein types, were distributed. In the Southeast Asian countries, mungbean strains characterized by various sized seed with shiny green seed testa, which show tall plants with high branching habit, late maturity, and simple protein type composition were distributed. In East Asia, mungbean strains characterized by medium-sized dull green seed testa, which show short plants with an early maturity, low-branching habit and relatively diverse (similar to that of West Asia) protein types, were distributed.

<Uses>

In the South Asia, mungbean is used to make "dhal", which is the most common dish made from various kinds of split legumes with spices. In the Southeast and East Asian countries, mungbean is used to make various kinds of sweet, bean jam, sweetened bean soup, vermicelli, and bean sprout.

<References>

Hoshikawa,K. 1981. Ryokutou (Mungbean). in "Shokuyou Sakumotu" (Food Crops). Yoken-do, Tokyo. (in Japanese) pp.470-475.

Katsuta,M. and M.Takeya. 1992. Exploration and Collection of Grain Legumes and Millets in Okinawa Prefecture. Annual Report of Exploration and Introduction of Plant Genetic Resources. Vol.8 : 1-8. NIAR, MAFF. Japan. in Japanese with English Summary.

Maeda, K. 1987. Mame to Ningen (Legumes and man). Kokin Shoin, Tokyo. (in Japanese).

Marechal,R., J.M.Mascherpa and F.Stainer. 1978. Etude taxonomique d'un groupe complexe d'speces des genres Phaseolus et Vigna (Papilionaceae) sur la base de donnees morphologiques et polliniques, traitees par l'analyse informatique. Boissiera 28.

Purseglove, J.W. 1974. Phaseolus aureus In "Tropical Crops : Dicotyledons." London : Longman. pp.290-294.

Tateishi,Y. 1996. Systematics of the species of Vigna subgenus Ceratotropis. In "Mungbean Germplasm : Collection, Evaluation and Utilization for Breeding Program" JIRCAS Working Report No.2. pp.9-24. Japan International Research Center for Agricultural Science (JIRCAS), Japan.

Tomooka,N. 1991. Geographical Distribution of Seed Characters in Mungbean. In "Genetic Diversity and Landrace Differentiation of Mungbean, Vigna radiata (l.) Wilczek, and Evaluation of its Wild Relatives (The Subgenus Ceratotropis) as Breeding Materials" Techinical Bulletin of Tropical Agriculture Research Center. No.28. pp.10-17. MAFF, Japan.

Tomooka,N., C.Lairungreang, P.Nakeeraks and C.Thavarasook. 1991. Geographical Distribution of Growth Types in Mungbean, Vigna radiata (l.) Wilczek. Japanese Journal of Tropical Agriculture 35(3): 213-218.

Tomooka,N., C.Lairungreang, P.Nakeeraks, Y.Egawa and C.Thavarasook. 1992. Center of genetic diversity and dissemination pathways in mung bean deduced from seed protein electrophoresis. Theoretical and Applied Genetics. 83:289-293.

Tomooka,N., H.Nakayama, K.Yamada and A.Sugimoto. 1994. Exploration for Collecting Landraces of Cultivated Crops in Tanegashima and Yakushima Islands, Kagoshima Prefecture. Annual Report of Exploration and Introduction of Plant Genetic Resources. Vol.10 : 15-24. NIAR, MAFF. Japan. (in Japanese with English Summary)

Zatsumame Yunyu Kikin Kyokai. 1995. Yunyu Mamerui Zukan (A pictorial book of imported food legumes) (in Japanese).