Induced variability in mungbean [Vigna radiata (L.) Wilczek)

Abstract

The present study was conducted to evaluate the effect of gamma rays, EMS and ECH on four quantitative characters in mungbean ( Vigna radiata L.). Mungbean, being a self-pollinated crop, has very limited genetic variability and induced mutations can provide additional source of variability in an ongoing breeding programme [1]. Hence an experiment was conducted to evaluate the extent of genetic variability in the four quantitative characters in M2 generation following mutagenesis with gamma rays, Ethyl methane sulphonate (EMS) and Epichlorhydrin (ECH). Uniform, healthy and dry seeds of mungbean cv. PS-16 were exposed to 20, 30 and 40 kR doses of gamma rays (Source Cobalt 60), EMS (0.05, 0.1, 0.2 and 0.3 per cent) for 6h and ECH (0.1, 0.2, 0.3 and 0.4 per cent) for 6h. The solutions of EMS and ECH were prepared in phosphate buffer (pH = 7.4). After the treatment, the seeds were dipped in 5 per cent aqueous solution of sodium thiosulphate for 10 minutes and then washed thoroughly with running water. Seeds soaked in distilled water for 6h were used as control. Complete randomized block design was used to raise M1 and M2 generations. Seeds from all the M1 plants of each treatment were harvested and were bulked to grow a representative bulk M2 generation. Observations were recorded on 60 randomly selected plants from each replication and there were three replications. Data recorded on a total of 180 plants to study four quantitative traits viz., number of pods/plant, number of seeds/pod, 100-seed weight and plant yield. The range of induced variability was assessed by basic statistics such as range, mean, variance and coefficients of variation. Broad sense heritability (h2) and genetic advance were also estimated.