Abstract

                                Two ragi varieties viz.. MS. 2698 (Bihar) and Sarada (Andhrapradesh) were treated with N-methyl-N-nitroso N-nitroguanidine. The germination, survival and seedling height at transplanting got reduced as the dose of the mutagen increased in both the varities. MS. 2698 showed a higher percentage of sterility than Sarada consquent on the chemical treatment. The LD 50 based on survival was around 10 mM for MS. 2698 and 5 mM for Sarada. The chlorophyll mutation frequency estimated on M, seedling basis was much less than that estimated on My spike basis. Sarada recorded greater mutation frequency than MS. 2698. There was a varietal difference in the spectrum of mutation also. The variety Sarada recorded albino types besides xantha and viridis types. A higher percentage of tigring was also observed in Sarada as compared to MS. 2698. The mutagenic effectiveness and efficiency were conferred by the same dose 5 mM for two hours of chemical soaking.

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