Addya Singh, L.K. Gangwar, Pooran Chand, Atar Singh, Hitesh Kumar, Vaishali and Shalini Gupta
Abstract
Genetic divergence is an important consideration in rice improvement because the choice of genetically distinct and agronomically complementary parents can broaden the range of variation available to selection. The present study assessed divergence among rice genotypes using multivariate cluster analysis and Tocherâs method based on 30 quantitative characters. Eight clusters were obtained from cluster analysis. The intra cluster distance ranged from 0.00 to 6557.19, with Cluster V showing the greatest within-cluster divergence, while Clusters VII and VIII were solitary groups. Inter-cluster distances were highly variable, with the largest separation occurring between Cluster VII and Cluster VIII (217179.60), followed by Cluster V and Cluster VII (152994.00) and Cluster IV and Cluster VIII (149372.50). Cluster means also differed appreciably for several characters. Cluster VII had the highest means for Characters 1, 3, 7, 8, 13 and 16, whereas Cluster VIII recorded the highest means for Characters 4, 5, 9, 12, 21, 22, 23, 25 and 29. The large distance between Clusters VII and VIII indicates that these groups represent contrasting multivariate profiles and may be useful for selecting parents when their individual performance is favourable for the target breeding objective. The results support the use of multivariate divergence as an aid to parent selection, while emphasizing that genetic distance should be considered together with yield, drought response and other desirable attributes.