Heritability for Grain Size of Rice (Oryza sativa L.) Estimated from Parent-Offspring Correlation and Selection Response

Abstract

In order to examine the selection efficiency of rice grain size, the narrow-sense heritability was estimated for grain length and grain width from parent-offspring correlation and selection response in segregating populations from various cross combinations. Five cultivars, BG 1, Arborio J1, Taihou, Nakateshinsenbon and Koshihikari, were used as parents. The heritability estimate averaged over ten F₂ populations was 0.800 for grain length, and 0.555 for grain width when estimated from parent-offspring correlation, Among the ten populations, there existed a positive correlation between heritability estimate and the magnitude of genetic variance for both grain length and grain width. The average heritability estimate for grain length obtained from selection response was 0.679. The narrow-sense heritability estimates for grain length and grain width were high in general as compared with heritability for other agronomic traits in rice. The estimates for grain length and grain width did not fluctuate drastically with generation advancement from F₂ to F₄. The present results suggest that selection for grain size of rice is effective even in early segregating generations after crossing.