Assessment of genetic divergence using Mahanalobis D2 and principal component analysis in dolichos bean (Lablab purpureus L.)

Abstract

Studies were carried out to assess the genetic divergence
among thirty genotypes of dolichosbean using Mahanalobis
D2 and principal component analysis of seventeen
quantitative traits. Thirty genotypes of dolichos bean were
grouped into six clusters. Maximum nine genotypes were
included in cluster I and minimum (1) in cluster VI. Maximum
inter cluster distance (92.76) was observed between cluster
IV and VI and minimum (53.45) between the cluster III and
cluster VI. The genotypes of cluster IV were observed with
highest character mean for pod width, pod weight, green
pod yield per plant and genotypes of cluster V recorded
highest mean for number of pod pickings, 100 seed weight,
less YBMV incidence and earliest days to flowering and
earliest days for green pod harvest. Principal component
analysis showed more than 93 per cent of variability for
quantitative character in different genotypes. Days to 50%
flowering, pod width, vine length, days to last green pod
harvest were observed significant variable components and
CG-2, CG-8, CG-14, CG-20, CG-21, VRSEM-186 and Pusa Sem-
2 were found with maximum value corresponding to these
variables. Selecting genotypes from divergent clusters and
utilizing them in hybridization programme is likely to produce
desirable recombinants, and may lead to improvement in
dolichos bean for yield and its contributing traits