GENETIC DIVERGENCE IN OLEIFEROUS Brassica species

Abstract

Genetic divergence among 41 genotypes of rapeseed and mustard was estimated using D' analysis. In each case of three species B. napus, B. rapa and B. juncea the genotypes under study fell into six clusters. The inter-cluster distances were larger than the intra-cluster distances in each species suggesting wider genetic diversity among the genotypes of each species. In Brassica napus Cluster II had the highest intra-cluster distance. Cluster I and III had no intra cluster distance because only one genotype was under each of the both clusters. Inter cluster distance was maximum between clusters II and IV. In Brassica rapa Cluster II had the highest intra-cluster distance and Clusters I, V andVl had the lowest intra cluster distances. Inter cluster distance was maximum between clusters I and IV. In Brassica juncea Cluster I had the highest intra-cluster distance while clusters II and VI had the lowest or no intra cluster distance. Inter cluster distance was maximum between clusters I and IV. The results revealed that genotypes chosen for hybridization from clusters with highest distances would give high heterotic F, and broad spectrum of variability in segregating generations.