Genetic divergence among maintainers and restorer lines of rice

Genetic divergence was worked out in 86 rice genotypes obtained from IRRI, DRR and other hybrid rice breeding centres at Directorate of Rice Research, Andhra Pradesh, India during wet season, 2008. Based on thirteen important yield attributes, the genotypes were grouped into ten clusters. Cluster IV was the largest with 21 genotypes from different centres, while the clusters V and X had 3 genotypes each. Cluster IV included 14 genotypes from IRRI, Philippines; 3 genotypes from DRR, Hyderabad; one each from PAU, Kapurthala; IARI, New Delhi; NDUAT, Faizabad and RARS, Maruteru. There was no relationship between geographical distribution and genetic diversity. Characters like plant height, 1000-seed weight, days to 50% flowering and number of filled grains per panicle had contributed more to the total divergence. These characters could, therefore, form the basis for selection of parents showing good mean performance from distinctly placed clusters to obtain heterotic combinations.