Induced Genetic Variability for Yield and Yield Components in Peanut (Arachis hypogaea L.)

An experiment was conducted during 2005-07 to induce polygenic variability for yield and its components in peanut (Arachis hypogaea L.). Two cultivars of peanut, 'GPBD-4' and 'TPG-41' were treated with γ-radiation (200Gy and 300Gy) and ethyl methane sulphonate (EMS- 0.5 %). The mutagenized populations showed significantly higher variability in the M2 generation. Mutant lines showing higher yield per plant than the respective parents and checks were isolated in M2 and subsequent generation. The evaluation of 10 superior mutants isolated in M4 over three successive generation yielded few mutants performing better over the parents and checks. In both the genotypes, superior mutants were isolated from 200Gy treatment, indicating effectiveness of the mutagen in obtaining the desired trait. Two of the mutant lines, G2-52 and TG2-30, gave significantly more pod yield (3,315 and 2,647 kg/ha respectively) than the parents and checks. One of the most interesting features of these mutant lines was the significant increase in hundred seed weight over the parent, contributing to higher yield. The mutant G2-82 recorded highest 100-seed weight of 40.28 g among GPBD-4 mutant population and T2-30 had 67.24 g as against parental value of (62.43 g). Mutants were found to be on par with respective parents for oil content, but had improved oil quality with their parental character of disease resistance/susceptible reaction. Magnitude of induced variation was found to depend upon the mutagen used, character under study and the genotypic background of the genotype. These promising mutant lines need to be further tested for their adaptability and stability. These can be further utilized in recombination breeding with other mutants and/or cultivars to derive distinct lines with improved agronomic traits. (author)