Genetic Analysis for Yield Components and Yield in Rice (Oryza sativa L.)

Component analysis indicated importance of both additive and dominance gene action for the characters days to 50% flowering, 50% flowering to maturity, plant height, panicle length, grain filling percentage and length-breadth ratio, while only the dominance component was important for the characters like effective tillers per plant, panicle weight, grains panicle⁻¹, 1000 grains weight and yield plant⁻¹. Dominant genes were more frequent in the parents than the recessive genes for the characters days to 50% flowering, 50% flowering to maturity, plant height, panicle length and length-breadth ratio. Unequal gene frequencies for positive and negative alleles in the parents were observed for all the characters except grains panicle⁻¹ for which equal gene frequencies were evident. The estimates of degree of dominance were more than unity for all the characters including yield plant⁻¹, which indicated prevalence of over-dominance.