Variability and Genetic Structure among Lablab Bean Collections of India and their Relationship with Exotic Accessions

Lablab purpureus (L.) Sweet is an ancient multipurpose legume that combines use as human food and forage in addition to serving as a cover crop for soil conservation. The crop is believed to be cultivated in south India as early as 1400 – 1500 BC. Although wide variability for agro-morphological traits exists in India, a more extensive germplasm collection and evaluation has not been reported so far. Hence the present study was undertaken with a set of 360 lablab accessions mainly collected from south India including nine accessions of exotic origin. All the 360 accessions were characterized for 29 qualitative and 10 quantitative traits. From genetic structure analysis using STRUCTURE software, the 360 accessions classified into seven groups indicating high level of genetic structure. Further, there exists very high genetic differentiation between the exotic and the lines of Indian origin as also evident from biplot and scatter plot analysis. Although the exotic lines deviated for the Indian lines for majority of the traits, much of the useful variation for genetic improvement of vegetable traits existed among the Indian accessions while, the exotic lines possessed traits of forage importance.