Vol. 8, Issue 10, Part S (2024)

Mutagenesis study in castor (Ricinus communis L.) was carried out to induce macro and micro mutational changes in two castor genotypes i.e., VP 1 (M) and SKI 215 using sole treatments of chemical and antibiotic viz., ethyl methane sulphonate (EMS) and streptomycin sulphate (S.S.). For mutagenesis, the germinating seeds of two genotypes of castor treated with EMS (50 and 60 mM) and streptomycin sulphate (1000 and 1500 ppm) studied by comparing their respective untreated controls. The LD₅₀ (Lethal dose) value was determined based upon the seed germination percentage. The analysis of variance between families revealed that mean squares of the ten families differed significantly for all the characters. The analysis of variance in M₂ generation between progenies within family indicated that progeny mean squares were significant for all the characters. This indicated that considerable variation was observed between progenies within families due to mutation treatments. The GCV and PCV higher in both the mutagenic treatments for all the characters except number of node up to primary raceme for SKI 215 and number of capsule on primary raceme in VP 1 (M). High estimate of GCV for above said characters indicated that sufficient genetic variability and selection based on genotype would be effective and little influence of environment present. High PCV which indicated that most of the characters were high influenced by the environment and selection should not be efficient. High broad sense heritability with high genetic advance as percent of mean was observed for seed yield per plant which indicates that expression of these traits was governed by additive gene action and as a result there was a scope for improving these traits through adopting selection procedure during advancement of progenies of mutant generations.