Studies on interrelationship in rice (Oryza sativa L.)

Correlation and path analysis studies on eight characters with 21 F1s and their seven parents in rice revealed that the genotypic correlations were slightly higher in magnitude than phenotypic correlations indicating that there was a strong inherent association between characters studied and their expression. Number of tillers per plant, number of filled grains per plant, panicle length, pollen fertility and plant height had positive and significant correlation with grain yield per plant at both phenotypic and genotypic level. Path analysis indicated that the number of tillers per plant exhibited highest direct positive effect on grain yield followed by number of filled grains per panicle, plant height and pollen fertility (%). Direct negative effect on grain yield was exhibited by spikelet sterility (%). Number of filled grains per panicle had high positive indirect effect on grain yield through panicle length, number of tillers per hill and pollen fertility (%). Pollen fertility exhibited positive indirect effect on grain yield per plant via panicle length and number of filled grains per panicle. Improvement in grain yield would be effective if the selection is exercised for more number of filled grains per panicle, productive tillers per plant and higher panicle length and pollen fertility percentage.