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Mutation breeding is the defined approach used for crop production and has played a key role in the creation of several varieties. The present research was carried out to induce mutants in kodo millet variety CO 3 using a physical mutagen (gamma rays) and a chemical mutagen (Ethyl Methane Sulphonate) for creating novelty. Seeds were treated with five doses of gamma-rays viz., 100 Gy, 200 Gy, 300 Gy, 400 Gy, and 500 Gy at BARC, Kalpakam and with three concentrations of EMS viz., 24.15 mM, 32.20 mM and 40.25 mM. In the laboratory test, root and shoot lengths of seedlings were decreased with an increase in the dose of gamma rays and EMS. In field study, the germination percentage and survival rate of seedlings were decreased with an increase in the dose of gamma irradiation and EMS. In M2 generation, five types of chlorophyll mutations viz., albino, xantha, striata, chlorina and albomaculata were observed. Xantha and chlorina were observed in all treatments, whereas, striata and albomaculata were observed only in 200 Gy. Based on the biological damages on M2 plants, mutagenic effectiveness and efficiency were estimated. Both mutagenic effectiveness and efficiency reduced with the increase in the dose of irradiation. Regarding height reduction and lethality, the dose of 100 Gy in gamma treatment and 32.20 mM concentration in EMS treatment recorded maximum efficiency. The mutagenic effectiveness was found to be higher at gamma rays irradiated with 100 Gy and in EMS, in 24.15 mM concentration. The 100 Gray dose and 24.15 mM concentration was found to be highly effective for inducing mutation in kodo millet.

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.