Variability and divergence in horsegram (Dolichos uniflorus)

Abstract

Horsegram is an important and unexploited tropic and sub-tropic legume crop grown mostly in dry land agriculture. The study involving 23 cultivars of horsegram (Dolichos uniflorus) was conducted at the Seed Research & Technology Centre in Rajendranagar, Hyderabad, India during the early spring seasons of 2008 and 2009 to assess the nature and magnitude of variability in the existing species and also to identify diverse parents for use in further breeding programmes. The results indicated significant differences among the 23 cultivars for all characters studied, indicating the presence of sufficient genetic variation. High variability and heritability coupled with high genetic advance were reported for seed yield per plant and pod hulm per plant, indicating additive gene action and a possible scope for the improvement of these characters. Mahalanobis D2 statistics grouped all the 23 cultivars of horsegram into six clusters. The maximum inter cluster distance (62.39) was noticed between cluster IV (HG 50) and cluster V (HG 11). The maximum intra cluster distance ranged from 0 (clusters III, IV, V and VI) to 15.17 (cluster I), indicating that the genotypes in these clusters were relatively more diverse than the genotypes within other clusters. Seed yield per plant contributed the maximum (33.20%) to the genetic divergence.