Determination of lethal dose and effect of physical mutagen on germination percentage and seedling parameters in kodomillet variety CO 3

Abstract

An experiment was conducted to estimate the lethal dose of the physical mutagen gamma ray in Kodomillet variety CO 3. Genetically pure seeds were treated with different doses of gamma rays viz. , 100 Gy, 200 Gy, 300 Gy, 400 Gy and 500 Gy. Untreated seeds were used as check for comparison. The LD 50 values were observed based on growth reduction of seedlings after gamma ray treatment. The LD 50 dose for gamma ray under in vitro and in vivo condition was fixed 300 Gy based on probit analysis. As the doses of applied gamma ray increased, there was a decrease in germination, survival rate of seedlings, root length, shoot length, seedling height, vigour index under in vitro conditions and emergence and survival under field ( in vivo ) conditions in M 1 generation as compared to the control.