Phenotypic characterization of common bean (Phaseolus vulgaris L.) accessions conserved at the Genetic Resources and Biotechnology Institute

Abstract

The purpose of this study was to access variability in qualitative and quantitative traits among ten accessions that were obtained from Genetic Resources and Biotechnology Institute (GRBI) in Zimbabwe. The accessions were planted in a Randomized Complete Block Design, with three replicates. The qualitative and quantitative characteristics were recorded using the International Board for Plant Genetic Resources (IBPGR) common bean descriptor list. The quantitative data for the number of days to fifty percent flowering, plant height, days to maturity, seed size, grain yield and number of seeds per pod were analysed using hierarchical cluster analysis Minitab Release 12.22 version and GenStat Discovery versions 14 software. Cluster analysis divided genotypes in two main groups when the dendrogram was partitioned at the 26:22 % similarity levels. Cluster A comprised of 2 bean genotypes and cluster B comprised of 8 genotypes distributed in 2 sub-groups. Genetic similarity among the accessions varied significantly depending on the genotype pairs, groups and sub-groups. The genetic similarity was lower between accessions of different clusters (A and B) and higher between accessions within each cluster. Significant differences (P<0.01) were observed among the accessions for the number of pods per/plant, number of seeds per pod, length and seed size. Based on different morphological characters exhibited by different accessions, it could be concluded that morphological diversity exists among the ten accessions of common beans. It can also be concluded that there are no duplicate accession among the ten common bean accessions.