​Genetic Variability Studies in Short Statured Early Maturing M3 Generation Cluster Bean [Cyamopsis tetragonoloba (L.) Taub.] Mutants

Abstract

Background: The present germplasm of cluster bean lack the needed natural variability for developing early maturing short statured lines. Therefore, an attempt was made to study the magnitude of heritable variability stimulated through induced mutation in M3 generation. Methods: M3 generation seeds of cluster bean variety MDU1 treated with gamma rays, electron beam and combination of gamma ray with EMS were used in the present investigation. The biometric observations were recorded on ten selected M3 plants from each family of every treatments for six traits viz., plant height, days to first flowering, number of clusters per plant, number of pods per plant, pod length and pod yield per plant. The same method was followed for recording observations on untreated parental materials also. Result: Studies on the variability parameters indicated that the phenotypic variance, genotypic variance, heritability and genetic advance were higher in combination treatment for all the traits. The shortest mutant and the earliest flowering (3M11) was observed in combination of 100 Gy of gamma ray+20 mM EMS. Mutant for the highest number of clusters (3M3) was observed in combination treatment of 300 Gy gamma ray with 20 mM EMS. The mutants for the highest number of pods per plant (3M1 and 3M2) and the highest pod yield (3M1) were identified at 400 Gy of gamma ray treatment. Fifteen desirable mutants were selected and forwarded to next generation for testing the stability in different environments.