Mutagenic effectiveness and efficiency of gamma rays in mungbean

Dry seeds (moisture, 9 per cent) of mungbean (Vigna radiata (L.) Wilczek) variety PS 16 were treated with ten doses of gamma rays (60Co) ranging from 10 to 100 kR. Plant survival and pollen fertility in X1, and, chlorophyll mutation frequency and mutagenic effectiveness and efficiency were studied in X2 generation. The plant survival and pollen fertility were reduced gradually with increasing dose. The chlorophyll mutation frequency increased in a linear fashion upto medium doses and was erratic at higher doses. The chlorophyll mutation spectrum included albina xantha, chlorina, virescence, viridis and maculata. Mutagenic effectiveness decreased with increase dose except at 60 kR. Mutagenic efficiency increased upto to 30 kR and thereafter it decreased. The decreasing trend of mutagenic effectiveness and efficiency at increased dose of gamma rays revealed that the biological damage (survival and pollen fertility) increased with increase dose at the faster rate than increase in rate of mutations induced. (author). 8 refs., 4 tabs