GENETIC VARIABILITY AND DIVERSITY OF UPLAND RICE LANDRACES

Abstract

Genetic variability and diversity studies provide important data for plant breeders who manage breeding programs. Forty-three upland rice genotypes collected in Thailand were assessed genetic variability using randomized complete block designs with three replications in two years at the Faculty of Natural Resources, Prince of Songkla University. The eight characterized quantitative traits showed significant variations by genotypes. For the interaction genotype×year, significance was found in days to maturity, plant height, number of tillers hill-1, yield, and 1,000 seed weight. High genetic coefficients of variation were observed for days to flowering, plant height, number of tillers hill-1, 1,000 seed weight, and seed width. High broad-sense heritability was found for days to flowering, days to maturity, plant height, number of tillers hill-1, 1,000 seed weight, and seed width. Cluster analysis grouped the 43 genotypes into eight groups based on SSR markers at 0.752 similarity level. These results expose the broad variability and assist rice breeders in selecting the appropriate genotypes for future breeding programs.