Abstract

                                Twenty-five rice varieties were evaluated for their genetic diversity with regards to grain yield, yield components and grain quality characters. The varieties were classified into six clusters, based on Mahalanobis D2 statistics. Geographical and genetic diversity were observed to be unrelated, as varieties from diverse geographical regions were placed in the same cluster, while varieties from the same centre were grouped into different clusters. Results on inter-cluster distances revealed maximum diversity between varieties of cluster V and VI. Intra-cluster distance was maximum for cluster III, indicating the existence of variability within the cluster for the characters studied. A perusal of the results on cluster means revealed higher grain yield per plant, more number of productive tillers and number of filled grains per panicle for cluster II, while long panicle length and high head rice recovery were noticed for cluster VI, indicating the desirability of selection of varieties from these clusters for improvement of grain yield and the above yield and quality traits. Further, days to maturity and 1000 seed weight, together had accounted for 70.33 per cent of the total genetic divergence indicating their importance in the choice of parents for hybridization programmes.

Key words : D2 analysis, Genetic divergence, Quality characters, Rice, Yield, Yield components