Genetic variability, correlation and path coefficient analysis for yield and its contributing traits in rice (Oryza sativa L.)

The analysis of variance, genotypic and phenotypic correlation and path coefficient analysis of yield and yield related traits in 20 genotypes of (Oryza sativa L.) was conducted in experimental area of Department of Plant Breeding and Genetics, University of Agriculture Faisalabad, following randomized complete block design with three replication. Data was recorded and statistically analyzed for characters; days to heading, days to maturity, plant height, number of tillers per plant, flag leaf area, number of filled grain per panicle, panicle length, grain per panicle, 1000-grain weight and grain yield per plant, the results of analysis of variance showed highly significant differences among the genotypes for yield and yield related traits. Among yield related traits plant height, number of tillers per plant, panicle length, area and grains per panicle reflected positive phenotypic correlation while positive and non-significant correlation with days to heading, days to maturity and 1000-grain weight but negative and non-significant with flag leaf area with plant yield at phenotypic level. Whereas at genotypic level plant height, number of tillers per plant, panicle length and number of grain per panicle showed positive and significant correlation with grain yield while positive and non-significant with flag leaf area, 1000grain weight, days to heading and days to maturity. Results of path analysis revealed that number of filled grain of panicle had maximum direct effect on seed yield followed by plant height, days to maturity, days to heading and 1000-grain weight. Panicle length had maximum negative direct effect on seed yield followed flag leaf area and number of tillers per plant. Days to heading had positive indirect effect via all study traits except via flag leaf area. Days to maturity had positive indirect on seed yield via days to heading, plant height, panicle length and 1000-grain weight. Flag leaf area had negative indirect effect via days to heading, panicle length and 1000-grain weight. Plant height had positive indirect effect on seed yield via days to heading, days to maturity, number of filled grains per panicle while negative via flag leaf area, tillers per plant and panicle length. Tillers per plant had positive direct effect on seed yield via days to heading, days to maturity, flag leaf area and panicle length. Panicle length had negative indirect effect on seed yield via days to heading, flag leaf area and 1000-grain weight. Number of filled grain per panicle had positive indirect effect on seed yield via days to heading, plant height, number of tillers per plant while negative via days to maturity, flag leaf area and panicle length, 1000-grain weight had negative indirect effect on seed yield via flag leaf area, plant height, number of tillers per plant, panicle length and number of filled grains per panicle. Number of filled grains, number of grains per panicle, plant height, and days to heading had positive direct effect on seed yield and highly significant correlation with seed yield so these traits may be used as selection criteria.