Mutation studies in M4 generation of cluster bean [Cyamopsis tetragonoloba (L.) Taub.] for various quantitative traits

Abstract

Mutation breeding is one of the best ways to induce genetic variability within a crop species in a short period of time. Cluster bean a leguminous crop where hybridization is a tedious and expecting less crossed seed. On other hand induction of mutation through physical irradiation is a potentially tool for its genetic improvement. The gamma radiation induced 190 M4 mutant lines of cluster bean [Cyamopsis tetragonoloba (L.) Taub.] obtained from Centre for Biotechnological Research (CBR), College of Horticulture, Bengaluru and which were used for the field experimentation on various quantitative traits (June - November) at College of Horticulture, Mysore. The knowledge of genetic variability and association of various characters are essential in planning of any breeding programmes. In the present study, 190 M 4 mutants of cluster bean were investigated for spectral variability for quantitative traits. The proportions of variability, broad sense heritability and genetic advance over mean were estimated. Analysis of variance revealed highly significant difference among the mutants for all the quantitative characters studied. Genetic variation as part of different component traits of yield was worked out, genotypic (GCV) and phenotypic (PCV) coefficient of variation, heritability and genetic advance over mean (GAM) were computed for all traits studied. Among all, High estimates of GCV and PCV were found for plant height (cm), branches per plant, pod length (cm), days to 50 per cent maturity, pod width (cm), Days for harvest, pods per cluster, pod clusters per plant, pods per plant, 10 pods weight (g), pod yield per plant (g), seeds per pod, seed yield per plant (g) and 100 seed weight (g). The performance of mutants C84, C114 and E179 for various quantitative traits was found good.