Mutation study of gamma ray in M3 generation of Soybean (Glycine max. (L.) Merrill)

Two well recommended high yielding varieties of Soybean for Jharkhand namely, BSS-2 and RKS-18 were exposed to five different doses (50 Gy, 100 Gy, 150 Gy, 200Gy and 400 Gy) of gamma rays using cobalt 60 (Co60) sources of Gamma chamber at Bhabha Atomic & Research Centre, Mumbai and their M3 progenies were screened thoroughly. Morphological (viable) mutants were observed and recorded in M3 generation from early seedling stage till physiological maturity with different doses of Gamma rays. Difference was observed between the varieties BSS-2 and RKS-18 in the degree of tolerance to the mutagens. The germination percentage was calculated in M3 by counting the number of plants germinated after 15 days from the date of sowing in each progeny rows of the varieties, BSS-2 and RKS-18. Germination and survival percentage in both the varieties was lower as compared to control. Reduction in germination percentage was associated with increase in dose of mutagen in both varieties BSS-2 and RKS-18. It is evident that the survival percentage of plants decreased with the higher doses of gamma radiation. In variety BSS-2 at 100 Gy a higher survival percentage (94.20%) was recorded as compared to lower dose 50Gy (93.35%) while in RKS-18 the lower dose of 50 Gy(88.42) showed much higher survival percentage in comparison to higher doses of 150 and 400 Gy