Genetic Diversity and Correlation Studies for Early Mature Yield and Quality Traits in Elite Rice (Oryza sativa L.) Germplasm

The presence of sufficient genetic variability, the knowledge of nature of association among different characters and relative contribution of different characters to yield is a pre-requisite to any breeding programme. The aim of the present study was to estimate genetic parameters of thirteen yield attributing traits in thirty seven rice cultivars with a view to select better yield attributes in rice. Genotypes IRRI 5 was found to be superior for grain yield per hill among 37 rice genotypes of rice followed SHIATS DHAN 2, SHIATS DHAN 1 and SHIATS DHAN 3. The higher value of phenotypic co-efficient of variation (PCV) compared to the corresponding genotypic coefficient of variation (GCV) for all the studied traits indicated that there was an influence of the environment High to moderate GCV and PCV were recorded for grain yield per hill, number of spikelet?s per panicle, panicles per hill, tillers per hills, biological yield per hill and test weight respectively suggesting that there was preponderance of additive gene action. High estimates of heritability coupled with high genetic advance as percent of mean was observed for number spikelet per panicle (99.5%, 37.73%), grain yield per hill (92.0%, 37.69%), biological yield per plant (94.7%, 31.00%) respectively suggesting that there was preponderance of additive gene action governing the inheritance of this character and offers the best possibility of improvement through simple selection. At both genotypic and phenotypic levels, significant positive correlations were observed for grain yield per plant with Grain yield indicated significant positive correlation with harvest index, biological yield, number of spikelet?s per panicle, days to 50 percent flowering, days to maturity, number of panicles/ hill, flag leaf length, number of tillers per hill, test weight and plant height, flag leaf width. All the37 Rice genotypes were classified using Mahalanobis D2 statistics involving 17 quantitative traits through this method. Based on D2 values 37 genotypes grouped into 5 clusters. Among 5 clusters cluster I had more number of genotypes (30) followed by cluster II (4 genotypes), remaining all clusters had (1 genotype) each. The maximum intra cluster distance were observed in cluster II and highest inter cluster distance observed between cluster IV and cluster V and cluster III and cluster IV crosses involving genotypes from these clusters would give wider and desirable recombination?s. Therefore, genotypes present in these clusters are suggested to provide a broad spectrum of variability and may be used as parent for future hybridization programme to develop desirable genotypes.