Assessment of phenotypic diversity of Kenyan dolichos bean (Lablab purpureus L. sweet) germplasm based on morphological markers

Abstract

In Kenya, lack of phenotypic diversity assessment of Lablab has hindered its improvement. It is common to find that morphologically similar cultivars do not bear the same name while cultivars bearing the same name may not be identical morphologically. The aim of this study was to clear the ambiguity that exists in differentiating between the various phenotypes of Lablab. The morphological method is the oldest and considered the first step in description and classification of germplasms. Forty five accessions of Lablab collected from farmers’ fields in Rift Valley, Eastern, Coast and Central regions of Kenya were planted at Kenya Agricultural and Livestock Research Organization, Njoro farm. A descriptor from Asian Vegetable Research Development Center was used as a guide. Results on means separation showed a high level of variability in quantitative traits and a low level of variability in qualitative traits. Eigen vectors derived from principal component analysis indicated that seed yield per plant, number of pods per plant, plant height and days to 90% mature pods contributed highly to total diversity in Lablab. In conclusion, Lablab germplasm grown in Kenya is morphologically diverse in quantitative traits where different genotypes are distinctly dissimilar.