Estimation of Variability, Correlation Coefficient and Path Analysis in Improved Restorer Lines of Rice (Oryza sativa L.)

The present investigation was conducted to estimate genetic variability parameters such as genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability (h2) and genetic advance (GA) along with correlations and path coefficients from data collected on 40 F4-F5 population derived from a cross between aerobic restorer AR 9-18 and blast resistant donor MSM 1212 possessing Pi54. Analysis of variance indicated significant differences among the genotypes for all the characters studied. Moderate GCV and PCV was observed for number of productive tillers per plant, number of grains per panicle, per day productivity and single plant yield. High heritability coupled with high genetic advance as percent of mean were observed for number of productive tillers per plant, number of grains per panicle, per day productivity and single plant yield, whereas high heritability coupled with moderate genetic advance as percent of mean were observed for panicle length, spikelet fertility, thousand grain weight and plant height. Grain yield per plant showed positive correlation with per day productivity, days to 50% flowering, panicle length, number of productive tillers per plant, thousand grain weight and spikelet fertility, while, negative association with number of grains per panicle and plant height. The trait per day productivity had highest direct effect on single plant yield followed by days to 50% flowering, panicle length, number of productive tillers per plant, thousand grain weight, spikelet fertility (%). Hence, per day productivity and number of productive tillers per plant are identified as key traits for developing high yielding genotypes of rice for future breeding programme.