Frequency and spectrum of chlorophyll mutations induced by gamma rays and diethylsulphate in blackgram (Vigna mungo (L.) hepper)

Studies were made to assess the frequency and spectrum of chlorophyll mutations induced by gamma rays and diethylsulphate (dES) in blackgram (Vigna mungo(L.) Hepper). Dry seeds of varieties IPU94-1 and PU19 were irradiated with 0, 200, 400, 600 and 800Gy gamma rays and then treated with with 0, 0.1, 0.2 and 0.3% dES for 2h. M2 mutation frequency (MF) was greater in IPU94-1 than. PU19. Gamma rays (800Gy) in.duced the highest MF of 2.12% in IPU94-1 and 1.80% in PU19. In dES treatment (0.3%), the highest MF were 1.09% and 1.46% in IPU94-1 and PU19, respectively. The synergistic effect of the mutagens on MF was observed at higher doses. The highest MF in IPU94-1 was 5.54% induced by 800 Gy gamma rays+0.3% dES, while in PU19, the highest MF (3.31%) was induced by 600 Gy gamma rays+0.3% dES. Mutation spectrum consisted of 13 mutant types. Mean frequencies of albina, viridis and xantha were 9.4, 37.2 and 20.2%, respectively in IPU94-1 and 7.9, 40.2 and 31.1%, respectively in PU19. In gen ral, the mutagenic efficiency and effectiveness were higher at lower doses of mutagens, while dES was more efficient and effective than gamma rays.