MUNGBEAN VARIETAL IMPROVEMENT S. Shanmugasundaram

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Origin
Mungbean probably originated in India (De Candole, 1886; Zhukovsky,
1950; Bailey, 1970) or the Indo-Burmese region (Vavilov, 1951; H.B. Singh et al.,
1970; Jain and Mehra, 1980). The primary gene center of diversity for mungbean
was suggested to be the central Asian region (Vavilov, 1951) with India as the
gene center and probable center of domestication (Smartt, 1985). Lukoki et al.
(1980) proposed that V. radiata var. sublobata (Roxb.) Verde. that occurs wild in
India and crosses easily with V. radiata var. radiata is the wild ancestor of
mungbean.
Genetics, Qualitative Characters
Literature on genetic studies of mungbean largely comes from India where
a vast array of researchers work on the crop. With mungbean, genetic studies are
sparse compared to crops like soybean, due to lesser economic importance of the
crop and less funding for research.
Early genetic studies of mungbean were conducted in India by Bose (1939).
Before 1.980, 45 different qualitative characters were identified. Recognizing that
there were no rules for gene nomenclature for Vigna, Fery (1980) suggested that a
set of rules proposed for Curcurbitaceae be adopted for Vigna. Thus far no one has
responsibility for maintenance of a genetic type collection of mungbean although
there is a need for this activity. Fery (1980) developed a detailed review of the
genetics of Vigna including V. radiata var. radiata. Poehlman (1991) extended the
review to include genes identified after 1980.
Disease and Insect Reaction
Mungbean is attacked by many pathogens. These include fungi, bacteria,
viruses, and nematodes. For reviews of the genetics of disease resistance see
Rachie and Roberts, 1974; D.P. Singh, 1981, 1982, 1986; Fery, 1980; Poehlman,
1991. Many studies report on screening of accessions for resistance but few
studies report on inheritance of resistance.
Leaf Spots: Resistance to bacterial leaf spot (BLS), a disease incited by
Xanthomonas phaseoli (Smith) Dowson, and Cercospora leaf spot (CLS), caused
by Cercospora canescens Ellis and Martin, are each conditioned by single
dominant genes according to D. Singh and Patel (1977), Thakur et al. (1977a, b,
c), and AVRDC (1981a, b). However, Yadav et al. (1981) reports resistance to
BLS to be governed by a single recessive gene. It was shown that peroxidase
polymorphism may be used as a selection index for CLS resistance (Menancio and
Ramirez, 1977). Resistance to angular black leaf spot disease caused by
Protomycopsis phaseoli in the variety LGG 450 (immune) is governed by a single
dominant gene (Cheralu and Satyanarayana, 1993)