Genetic Variability, Heritability and Genetic Advance of Yield and Yield Contributing Characters in Putative M2 Dolichos Bean (Lablab purpureus L.) Accessions

Dolichos bean (Lablab purpureus L.) is a multipurpose, orphan leguminous crop in Kenya .It is characterized with narrow genetic diversity and low yield output. Use of nuclear techniques such as gamma ray induction in breeding for improved genetic variability is an effective approach in improvement of this important crop. Studies on genetic variability estimates of two Kenyan dolichos bean accessions were undertaken as the pre-requisites for selection of potential high yielding putative accessions for production. This study was conducted between May 2020 and October 2020 at biotechnology department, University of Eldoret research field, Kenya. 0gy, 300gy and 400gy mutant accessions of Eldo maridadi and Eldo black I respectively were raised in Randomized Complete Block Design (RCBD) with three replications. Data was collected either on plot basis or from randomly taken 3 plants on days to 50% flowering, leaf length, number of flower buds per race , raceme length (cm) , plant height (cm), number of nodes per raceme , pod length (cm), 100 seed weight (g), dry seed yield (g). The data collected for each quantitative trait was subjected to analysis of variance (ANOVA) for simple lattice design. There was high PCV and GCV coupled with high heritability in, raceme length (cm), plant height (cm), number of nodes per raceme, pod length (cm), 100 seed weight (g), dry seed yield per plant (g) in Eldo black I accession traits than in Eldo maridadi .The different accession following mutation did exhibit difference in trend of genetic variability estimates. An indication of genotypic differences, response to mutation, lesser influence of environment in expression of the traits, prevalence of additive gene action in their inheritance and amenability of the traits to simple selection. Eldo maridadi accessions exhibited high to low heritability with low genotypic advance as percent of mean in evaluated traits thus direct selection on this traits may not beneficial. Other traits or further improvements on yield potentiality and yield traits on the accessions of this genotype are suggested by creating variation and selection.