Relative Effectiveness and Efficiency of Single and Combination Treatments using Gamma Rays and Sodium Azide in Inducing Chlorophyll Mutations in Rice

Abstract

Seeds of rice cultivars Jaya, IET 5656 and Fujiminori were presoaked for 24 hours and then (a) irradiated with 4, 6, 8, 10 and 12 KR gamma rays, (b) treated with 0.001, 0.002, 0.004 and 0.005 molar solutions of sodium azide at pH 3 for 4 hours, or (c) subjected to combinations of the above with the view to study their relative effectiveness and efficiency in inducing chlorophyll mutations in rice. In all three varieties azide treated entries showed a higher frequency of chlorophyll mutants than did the gamma ray treated entries, under both single and combination treatments. In the variety Jaya sodium azide treatments showed a higher efficiency and effectiveness than gamma rays and combination treatments and they were more or less similar in both single and combination treatments in the other two varieties. The indica cultivars Jaya and IET 5656 were more sensitive than the japonica cultivar, Fujiminori to producing chlorophyll mutations. Sodium azide appears to be more efficient than gamma rays alone or in combination.