INDUCTION OF GENETIC VARIABILITY FOR POLYGENIC TRAITS THROUGH PHYSICAL AND CHEMICAL MUTAGENS IN COWPEA [VIGNA UNGUICULATA (L.) WALP]

An investigation was carried out to estimate the genetic variability induced through physical and chemical mutagens in cowpea. The seed of cowpea variety RC 19 were treated with gamma rays and ethyl methane sulphonate (EMS), in M-2 generation indicating significant differences in the mean value of treated population. The mean values for plant height, number of primary branches, number of pods, number of grains, 100-seed weight and seed yield reduced significantly with increasing concentration of both the mutagens. Protein content and biological yield increase significantly with increasing doses of both the mutagens. The study revealed that magnitude of phenotypic coefficient of variation was distinctly high for plant height, number. of pods per plant, seed yield per plant, biological yield, harvest index and protein content. Phenotypic coefficient of variation was higher then genotypic coefficient of variation except in protein content for family EMS 0.1 %. The gap between GCV and PCV was narrow which reflect lesser degree of environmental influence on the genotypic variability