GENETIC VARIATION AND PATH ANALYSIS ON AGRONOMIC TRAITS OF RECOMBINANT INBRED LINES IN RICE (Oryza sativa L.).

Genetic variability, heritability of traits, their association and direct and indirect effects on yield are essential for crop improvement. Therefore, forty nine recombinant inbred lines (RILs) were studied to evaluate these parameters, and to select the potential RILs with good agronomic characters among the tested lines. Significant genotypic variation was found in days to first flowering, days to 50% flowering, plant height, panicle length and total grains plant-1. Selection can be done among the RILs for these traits. These characters also showed a small difference between phenotypic coefficient of variation and genotypic coefficient of variation, and had high heritability indicating that the characters were less influenced by environment. Effective yield plant-1 showed significant positive correlation with effective tillers plant-1, number of total grain plant-1 and 1000 grain weight. This showed that direct selection on effective tillers plant-1, number of total grain plant-1, and 1000 grain weight would result yield improvement. The highest and positive direct effect on effective yield plant-1 was found in total grain plant-1 followed by effective tillers plant-1 and 1000 grain weight. Therefore, these three characters should be given priority for yield improvement. According to the heterosis, three RILs such as YAU 1215-B-B-B-168-1, YAU 1215-B-B-B-193-3 and YAU 1215-B-B-B-78-1 should be selected as promising lines.