GENETIC DIVERSITY, CORRELATION AND PATH ANALYSIS IN RICE (Oryza saliva L.)

Abstract

The experiment was conducted at the experimental field of Shcr-e-Bangla Agricultural University. Dhaka under the agro-ceological zone of Modhupur l'ract (AEZ-28) during January to June of 2011. The experiment was intended to estimate the nature and magnitude of genetic variability, correlation, path coefficient and genetic diversity of 39 rice genotypes collected from Bangladesh Rice Research Institute, Lal Teer Seed Ltd. and Chittagong lull Tracts. All the characters tested showed significant variations among the genotypes. High genotypic coellicient of variation was observed for grain yield and number of unfilled grains per panicle. I ugh heritability coupled with high genetic advance in percent of mean was observed in grain yield, harvest index. 1000-grains weight, unfiLled grains per panicle. secondary branches number and plant height indicating additive gene control on the expression of these characters and that selection based on these characters might be effective. The significant positive correlations were recorded for number of effective tillers per plant. 1000-grains weight and harvest index with grain yield at both genotypic and phenotypie levels indicating that the improvement of these characters would lead to increase in grain yield. The highest positive direct effect on grain yield for harvest index followed by number of filled grains indicated that the direct selection based on these characters would be effective for yield improvement. The genotypes were grouped into six clusters. Cluster I consisted of the highest II genotypes from different origin, whereas cluster IV consisted of the lowest three genotypes. The genotypes of Chittagong llill Tracts were distributed in different clusters indicated that the geographical distribution was not related to genetic diversity. The highest inter genotypic distance was observed between Tharak c/han and BRRI dhan 45 and the lowest between BRRI dhan 33 and BRRI dhan 50. The highest inter cluster distance was observed between cluster II and Ill and the highest intra cluster distance for cluster IV. Cluster III had the highest mean values for grain yield, harvest index. 1000-grains weight and number of effective tillers and cluster V for number of primary branches and cluster VI for number of tilled grains that had significant positive correlation with grain yield. Considering all the data analyses, the genotypes BRRI dhan 36. Gold, BRRI dhan 28, Dowel, BRRI dhan 45, BRRI dhan 50 and indian Pajani could be selected for hybridization program.