Morphological characterization of common bean (Phaseolus vulgaris L.) landraces of Central region of Benin Republic

Common bean (Phaseolus vulgaris L.) is an important food consumed in every region in Republic of Benin; however, it remains a neglected and under-utilized crop. In order to assess the value of bean germplasm of the central region in the Republic of Benin for useful breeding programs, 57 accessions were collected from 23 villages. After a classification based on the morphological variables of the seeds, these accessions were evaluated using 30 morphological traits (18 qualitative and 12 quantitative) following the IBPGR descriptors in experimental field at Faculty of Sciences and Technology of Dassa. Based on the seeds morphological variability, the accessions have been grouped in 8 morphotypes. However, 9 morphological types were obtained with cluster analysis based on UPGMA classification method using qualitative variables, whereas in Principal Component Analysis (PCA) they were gathered into 4 clusters using quantitative variables. The accessions in cluster 1 (11 accessions) were identified as possessing the highest values in quantitative traits like days to maturity, and number of pods per plant. While accessions in cluster 2 (3 accessions) have had the lowest number of days to flowering and the highest pods length, the accessions of cluster 3 (23 accessions) presented the highest 100-seed weight. Correlation coefficient of 100-seed weight was positively significant (p ≤ 0.001) with leaf length, pod width, and seeds length while it was negatively correlated (p ≤ 0.05) with days to flowering, pod length and the number of seeds per pod. Cluster 3 accessions may serve as useful genetic material in future, for any breeding programmes to improve the productivity of other common bean accessions through hybridization. Key words: Common bean, cluster analysis, diversity, landraces, qualitative traits, quantitative traits.