Genetic Divergence Analysis in Rice under Irrigated Conditions

The nature and magnitude of genetic divergence were estimated in 134 rice germplasm accessions during kharif 2013 using Mahalanobis D2 statistics. The genotypes were grouped into five clusters based on Euclidean cluster analysis. The pattern of distribution of genotypes into various clusters was random and independent of geographical origin or region of adoption indicating geographical diversity and genetic diversity were not related. Cluster means indicated considerable differences in the mean values of different traits. The genotypes of cluster II and cluster III exhibited high seed yield. The highest intra-cluster distance was observed among the genotypes, in cluster IV (12.19) followed by cluster III (11.03) and cluster V (10.90) indicating existence of wide genetic divergence among genotypes. Number of filled grains/panicle contributed highest towards divergence. The relative divergence of each cluster from other clusters displaced higher order of divergence between cluster IV and V followed by clusters II and V. The hybridization involving genotypes belong to these clusters is expected to give desirable segregants in rice breeding programmes.