Abstract

                                Lower doses of gamma rays showed stimulatory effects and higher doses showed graded inhibitory effects with respect to germination percentage, period taken for germination and survival percentage. There existed very high negative, positive and negative correlations for dose with these characteristics respectively. At lower doses, seed viability itself is a good indicator for seedling survival whereas at higher doses, seedling survival reduced drastically in comparison to the reduction of seed viability, eventhough the rate of reduction showed a perfect positive correlation. LDso value was found to lie between 80 K rad and 100 K rad and expected to be 87.39 K rad. LDso for survival was 60 K rad. Cultivars showed differential response to LDso for survival was 60 K rad. Cultivars showed differential response to LDso values and lethality. Cultivars: IT-7 and IT-11 can be classified as radiation sensitive: IT-12 and NBPGR/WB-2 as medium radiation resistant and SLS-21 as radiation resistant.

Key words : Radiation sensitivity, winged bean, gamma irradiation, mutation.