Genetic variability, character association and path analysis of yield and yield attributes of rice genotypes at Lalitpur, Nepal

Rice is a staple for over half the world’s population. Location-specific varietal trials help identify suitable genotypes with desirable traits. A study in Lalitpur, Nepal, evaluated 12 rice genotypes in a randomized complete block design (RCBD) with three replications to assess genotypic variability, character association, and path analysis for yield-related traits. Observations from five randomly selected plants per plot were analyzed statistically. Analysis of variance revealed significant differences among genotypes for most traits, indicating ample genetic variability. Grain yield (20.26) showed the highest genotypic coefficient of variation (GCV), while effective tillers (24.26%) had the highest phenotypic coefficient of variation (PCV), followed by grain yield, straw yield, and tiller number. High heritability and high genetic advance as percent of mean were noted for days to flowering (35.15), total grain per panicle (34.84), tiller number (33.39), and panicle weight (31.55), suggesting additive gene control and selection potential. Grain yield was positively correlated with panicle length (r = 0.47**), total grain per panicle (r = 0.40*), panicle weight (r = 0.43**), tiller number (r = 0.34*), and straw yield (r = 0.62*). Path analysis showed total grain per panicle (2.55) had the highest positive direct effect on yield, alongside days to flowering, plant height, effective tillers, unfilled grains per panicle, and straw yield. Khumal-4, Khumal-8, and Taichung-176 emerged as superior genotypes. Hence, it is strongly advised that these traits be chosen in rice breeding programs to further enhance production. Khumal-4, Khumal-8, and Taichung-176 were the most promising genotypes.