Mutagenic response of rhodes grass (Chloris gayana Kunth.) to gamma rays. II. Studies on second (M₂) generation parameters

Abstract

The effect of gamma rays on parameters such as chlorophyll mutation frequency and spectrum, mutagenic effectiveness and efficiency and viable mutation frequency and spectrum were studied in M₂ generation of Rhodes grass employing nine doses of gamma rays. The chlorophyll mutation frequency increased in a linear fashion at low and medium doses and was erratic at higher doses. The chlorophyll mutant spectrum ineluded albina, xantha, chlorina, viridis, tigrina, striata, albo-xantha and albo-viridis. The frequency of these mutants varied with treatments. A dose rate of 60 krad was found to be effective as well as efficient both on M₁ and M₂ plant basis in inducing chlorophyll mutations. The highest frequency of viable mutations was found in 50 krad treatment. Viable mutants found were: nodal variant, peduncle variant, lax ears, coxcomb ears, earhead proliferation, level of fingers, incurved fingers, gappy ears, apical sterility, partial sterility and high sterility.