Efficacy of physical and chemical mutagenic treatments for developing productive mutants in blackgram

Two blackgram varieties Basant Bahar and Sarala were treated with three doses each of gamma rays (20, 40 and 60 kR), EMS (0.2, 0.4 and 0.6%), NG (0.005, 0.010 and 0.015%) and MH (0.01, 0.02 and 0.03%) coupled with combine mutagens of 40 kR gamma rays with 0.4% EMS or 0.010% NG or 0.02% MH. Twelve selected M₂ plants from each of the fifteen mutagenic treatments along with the parental variety were evaluated in M₃ generation. Out of180 M₃ progenies evaluated in each variety, 48 in Basant Bahar, and 25 in Sarala produced significantly higher yield than the respective parent variety. In case of Basant Bahar, combined treatments produced maximum high yielding progenies followed by gamma rays and EMS, whereas in caseofSarala,gammaraysyielded maximumhighyielding progenies followed by EMS and combined treatments in M₃. Bestthree high yielding progenies fromeach treatmentwere assessed for yield and eight yield attributing traits in M₄ generation. Out of 45 M₄ cultures each of Basant Bahar and Sarala, 11 and 7 cultures exhibited significant yield superiority over parental variety for one or more characters. High frequency of positive mutations was observed for clustersper plant, pods per plant, seeds per pod and100-seed weight in both the varieties. Considering both M₃ and M₄ generations together, gamma-rays and EMS treatments appeared to be most effective in producing high yielding progenies/cultures in Basant Bahar, while gamma rays, combined and MH treatments were most effective in producing high yielding progenies/cultures in Sarala. It was inferred that treatment with gamma rays (60 kR), MH (0.02%), EMS (0.04% or 0.06%) and combined treatment of gamma rays (40 kR) with MH (0.02%) or NG (0.01%) would be effective in induction and isolation of more useful mutants in blackgram.