Genetic Variability, Correlation and Path Analysis of Yield and its Attributing Traits in Rice (Oryza sativa L.)

Genetic variability in a species is a crucial aspect that determines its adaptability, resilience and potentiality for improvement. The present study was aimed to estimate variability, correlation and path coefficients of fifteen rice accessions from Kerala Agricultural University for grain yield and its attributing traits. PCV was found to be higher than GCV for all the characters studied. High PCV and GCV values were recorded for the traits like flag leaf length, leaf area, number of filled grains per panicle, fertility percentage and single plant yield indicating that direct selection can be employed for the improvement of these traits. High heritability coupled with high genetic advance was shown by the traits plant height, flag leaf length, flag leaf width, leaf area, number of filled grains per panicle, total grains per panicle and single plant yield. Hence direct selection will be highly effective for improvement of these traits. Single plant yield showed significant positive correlation with days to 50% flowering, number of filled grains per panicle, total number of grains per panicle and harvest index at phenotypic level and with harvest index at genotypic level. Path analysis has ascertained that there exist direct and indirect effects for all the independent traits studied. Positive direct effects on single plant yield at genotypic level was shown by the traits number of panicles, panicle length, 1000 grain weight, leaf area, grain length, kernel breadth and harvest index. The characters like days to 50% flowering, plant height, number of tillers, flag leaf length, flag leaf width, total number of grains per panicle, 1000 grain weight, kernel length, kernel breadth and L/B ratio had significant positive direct effects at phenotypic level. The results have shown that the accessions studied can be used for further selection for crop improvement programmes. The interactions between the contributing traits are so complex that a balanced method of selection is to be practised for their improvement.