Induced morphological mutants and mutagenic efficiency of gamma-irradiated mungbean (Vigna radiata (L.) Wilczek) M2 populations

In the present investigation, three mungbean varieties viz., Co 5, Co(Gg) 7 and VBN(Gg) 3 were exposed to six doses (450, 500, 550, 600, 650 and 700 Gy) of gamma rays. Based on probit analysis in the M1 generation, the LD50 was determined to be 600 Gy for all three varieties. A wide range of chlorophyll and morphological mutants, including viable and non-viable types, were observed in the M2 generation. The results indicated that the frequency of chlorophyll mutations increased at lower doses of mutagenic treatment, showing a slight decline in higher doses of mutagen in all three varieties. Mutagenic effectiveness and efficiency were found to decrease with increasing gamma-ray dose. Based on this investigation, it is exposed that the gamma rays have the potential to generate tremendous variability in mungbean genotypes. Varying degrees of mutant genotypes were observed in the M2 generation. Most are true breeding genotypes since they were detected in M3 and other generations. Among these, desirable mutants, viz., dwarf type, tall type, synchronized maturity, seed size and early and high yielding mutants, are noteworthy. These mutants can be utilized for further crop breeding programmess to evolve desirable genotypes with improved traits such as higher yield, enhanced pest and disease resistance, greater tolerance to environmental stresses and improved nutritive value. Likewise, mutants with distinct traits give a space to generate novel genotypes in mungbean that are more adaptable to challenging environmental conditions and consumer needs by harnessing genetic variations.