Genetic variability for morphometric traits and insect damage in Dolichos bean (Lablab purpureus L. Sweet) germplasm

The variability among 44 accessions of Dolichos bean (Lablab purpureus L. Sweet) was assessed for seven quantitative traits, and bruchid and pod borer infestations. The experiment was conducted during the Kharif season 2012-2013 at the University of Agricultural Sciences (UAS), Bangalore, India with two check entries (HA 4 and HA 3) in an augmented design using three blocks. A substantial variability among the accessions for quantitative traits, and bruchid and pod borer infestations, except for the number of branches per plant, was documented. The estimates of heritability were high for all the traits studied. The phenotypic and genotypic coefficients of variation, which reflect the average inter-accession differences, were moderate. However, these are useful statistics to understand variability among the accessions. The germplasm was grouped into seven clusters following Wards minimum variance clustering approach with significant deviations among clusters. The intra-cluster distance was lower compared to inter-cluster distance. Some of the accessions were superior to the check HA-4. The results could be used to adopt suitable strategies for breeding Dolichos bean aiming at improved productivity.