The present study was conducted to determine the variability, heritability, genetic advance and correlation among selected agronomic traits of 52 common bean accessions cultivated in South West, SW, Kenya at the Agricultural Research Farm of the Kenya Agricultural and Livestock Research Organization, KALRO, Kisii station during the growing seasons of 2015 and 2016. We investigated 14 quantitative traits following the IPGRI descriptors: PL- plant height, DTE-days to emergency, DTF-days to flowering, DTM-days to maturity, BY-biological yield, SYPP-seed yield per plant-1, SWHS- 100-grain weight, HI-harvest index, NoPP-number of pods per plant, NoSPP-number of seeds per pod and NoB-number of branches per plant. The field experiment consisted of a randomized complete block design (RCBD), replicated 3 times. Standard agronomic practices were carried out from land preparation, planting to maturity. Considerable agronomic trait variations were found among the genotypes. Computer package of numerical taxonomy methods, (NTSYS) was used to analyze data. The unweighted pair-group method of the arithmetic mean clustering technique (UPGMA) was used to generate a dendrogram and principal components analysis, PCA was applied to show the similarities and differences among the accessions.The phenotypic and genotypic variances were estimated for yield and the yield related traits for the genotypes using the means of the data generated followed bybroad sense heritability and. genetic advance. The results showed that the availability of genetic variance could be useful for exploitation through selection for further breeding purposes. This work indicated the presence of a wide-ranging variation among and within cultivated common bean landraces. Moreover, it provided evidence that the implementation of measures for their on-farm conservation, management and promotion should be useful also to preserve genetic variability. The results of these agronomic characterization for the South western Kenya common bean germplasm will lead to selection of representative landraces for conservation and provide genetic material to restore accessions that may be lost or reduced due to genetic erosion.
Keywords: Landrace, Phaseolus vulgaris, L., Randomized Complete Block Design, Genetic and Phenotypic Variability, Heritability and Genetic Advance