Genetic parameters of variability, correlation and path-coefficient for grain yield and physiological traits in rice (Oryza sativa L.) under shallow lowland situation

Studies on genetic variability, character association and path-coefficient analysis were conducted on forty seven (47) rice genotypes including thirty three hybrids and fourteen parents for grain yield and some physiological traits. Analysis of variance revealed considerable variability among the genotypes for all the characters. A high genotypic and phenotypic coefficient of variation was observed for grain yield per plant, harvest index, pollen fertility (%) and spikelet fertility (%). Characters like pollen fertility (%), spikelet fertility (%), days to 50% flowering and grain yield per plant showed high value of heritability coupled with high genetic advance. Spikelet fertility (%) and harvest index showed positive and significant correlation with seed yield per plant both at genotypic and phenotypic levels. Results of path-coefficient analysis revealed that productive tillers per plant had the highest positive direct effect on grain yield followed by harvest index, spikelet fertility (%), pollen fertility (%) and plant height. The study revealed that genetic improvement of grain yield in rice is admissible by selecting characters having high positive correlation and positive direct effect.