Morphological and microsatellite characterization of improved Lablab purpureus genotypes

Abstract

Lablab purpureus is a multipurpose legume mainly grown by subsistence farmers for pulse, forage and vegetable. Despite these diverse uses that can be combined successfully under various agronomic conditions, the bean has not been extensively exploited. Dolichos production in Kenya is constrained by low yielding varieties, pests, poor growing techniques and varieties with non-preferred taste and flavor. A study to characterize six newly bred Lablab genotypes (G2, B1, M5, LG1, W7 and G2), was initiated at the University of Eldoret using morphological and molecular markers. Morphological traits (qualitative and quantitative) were characterized using the descriptors of genus Lablab. Molecular characterization was done at the KEPHIS- Muguga laboratory, using ten SSR markers that are specific for Dolichos. Results from morphological characterization demonstrated a high variation for both qualitative and quantitative traits evaluated. Most of the quantitative traits were highly significant at 99.999% or (P≤ 0.001), except for number of racemes per plant and number of seeds per pod which were significant at 99.99% or (P≤ 0.01) and 99.95% or (P≤ 0.05), respectively. Microsatellite analysis produced six polymorphic primers mapping an average of 3.17 alleles per locus. The combination of morphological and DNA-based markers takes advantage of the best features of both marker types which can be beneficial in selection of best Lablab genotypes and in the process integrates the application of molecular markers to legume breeding.