Estimation of Genetic Diversity Among the Parental Lines in Rice (Oryza sativa L.) Using D² Statistics

The estimation of genetic diversity among 55 restorer lines and 2 CMS lines was done using Mahalanobis's D² statistics. The parental lines were grouped into eight clusters using D² statistic such that the genotypes belonging to same cluster had an average smaller D² values than those belonging to different clusters. Out of eight clusters, cluster II was the largest followed by cluster I and cluster VII. Both the CMS lines (APMS 6B and APMS 10B) along with one restorer line (TCNP 97) were found within a single cluster indicating their relatedness. Intra cluster D² values ranged from 0.00 (cluster III and cluster VI) to 99.88 (cluster VII). Maximum intra cluster distance was observed in cluster VI. The highest divergence occurred between cluster III and cluster VI followed by cluster II and cluster VI and cluster IV and cluster VI, suggesting that the crosses involving lines from these clusters would manifest greater heterosis.