Genetic divergence and cluster analysis studies in rice (Oryzasativa L.) using D2 statistics

Abstract

The nature and magnitude of genetic divergence was estimated in one hundred and fourteen F5 families of rice obtained from six different crosses along with their seven parents using Mahalanobis D2- statistics. ANOVA revealed the presence of considerable amount of variability among the genotypes. High PCV and GCV were observed for grain yield per plant and test weight. High heritability coupled with high genetic advance as per cent of mean was observed for number of grains per panicle, grain yield per plant and test weight indicating the presence of additive gene action in governing the inheritance of these traits. Hence, direct phenotypic selection is useful with respect to these traits. Mahalanobis D2 analysis revealed considerable amount of diversity in the material. The genotypes were grouped into twelve clusters. Cluster IX constituted maximum number of genotypes (26). The genotypes falling in cluster VII had the maximum divergence, which was closely followed by cluster VII and cluster XI. The maximum inter cluster D2 values was observed between cluster X and XI (931.276) followed by cluster VII and XI (814.784) suggesting that the genotypes constituted in these clusters may be used as parents for future hybridization programme.