Induction of genetic variability through gamma rays in pigeonpea (Cajanus cajan (L.) Millspaugh)

The present investigation was conducted to induce genetic variability for yield contributing traits in a local variety AL 201 and to isolate desirable mutants for important traits. Two doses of gamma radiation i.e. 300 Gy and 400 Gy were used to induce mutations. The effect of gamma rays treatment on the seed germination was studied in M₁ generation under both laboratory as well as field conditions and results indicated that the gamma rays had an inhibitory effect on the seed germination of pigeonpea and the negative effect was more severe with increasing dose of the mutagen. In M₂ generation, mutant plants were selected and were divided into different groups for desirable traits like earliness, dwarfness, profuse branching and higher yield per plant for both the doses i.e 300 Gy and 400 Gy. Mean of selected plants was significantly different from mean of control plants for all the traits studied. Among all the groups, group V (300 Gy) was considered as the best as it contained early, dwarf, profusely branched plants with higher yield than the parent variety AL 201. These mutants will be further evaluated for their release as new varieties or will be used as parents in hybridization programme for developing superior dwarf early varieties.