Induced polygenic variability using combination treatment of gamma rays and ethyl methane sulphonate in blackgram (Vigna mungo (L.) Hepper)
Induced mutation in plant improvement has been proven to be one of the alternative ways to generate new sources of genetic variation in blackgram. In this study, dry seeds of VBN 4 blackgram were treated with combination treatment of both gamma rays (400, 500 and 600 Gy) and ethyl methane sulphonate (EMS) (50, 60 and 70 mM) to study the polygenic characters in M2 generation. The mean values for plant height, number of primary branches, number of clusters per plant, number of pods per plant, number of seeds per pod and single plant yield decreased below the control in most of the treatments. The mean single plant yield was more than for the control at 400 Gy+60 mM and 600 Gy+50 mM. Moderate and high phenotypic coefficients of variation (PCV) and genotypic coefficients of variation (GCV) were recorded in yield component characters such as plant height, number of primary branches, number of clusters per plant and number of pods per plant. A high amount of heritability and GA as per cent of mean was noted for plant height, number of clusters per plant, number of primary branches per plant, number of pods per plant, pod length, number of seeds, 100 seed weight and single plant yield. This denoted that these characters are governed largely by additive gene effect, which may be favorably exploited for improvement through simple selection in M2 generation.
Key words: Gamma rays, ethyl methane sulphonate (EMS), blackgram, polygenic variability, M2 generation.