Abstract

                                Two varieties of rice bean (Vigna umbellata) cv. RBL-50 and L-1 were treated with gamma rays (50,60, 70, 80 and 90 KR), EMS (0.3, 0.4, 0.5 0.6 and 0.7%) and combination of gamma and EMS (30KR+ 0.2%, 40KR + 0.2%, 30KR+0.3% and 40KR+0.3%). Among the varieties, L-1 and among the mutagens, gamma rays induced more number of chlorophyll and viable mutants. The viridis types were predominent than albinia, xantha and chlorina types, irrespective of the variety. The gamma doses of 60KR in RBL-50; 50KR, 90KR in L-1 and among the EMS treatments 0.5, 0.6 per cent in RBL-50; 50 KR, 90KR in L-1 were considered the best doses/concentrations, based on mutagenic effectiveness and efficacy. Twelve types of viable mutants were observed with abnormal leaves and coloured seeds being prominent among them. In the variety L-1, the doses/concentrations which have brought out highest chlorophyll mutations, also brought out highest viable mutations.

Key words : Rice bean, Gamma rays, EMS, Chlorophyll mutation