Estimation of genetic parameters in hybrid and F2 generations of aromatic fine rice

Abstract

The present study was designed to analyze genetic parameters, heterosis, and inbreeding depression in F₁ and F₂ generations obtained from a crossing between fine and aromatic rice genotypes - Kataribhog and BRRI dhan50. A significant amount of variation was found from the analysis of variance among the genotypes of F₁, F₂, and their parents. Grain yield plant^-1 showed a significant positive correlation with the number of tillers hill^-1, number of effective tillers hill^-1, flagleaf length, panicle length, grains panicle^-1, filled grains panicle^-1, and grain yield panicle^-1. For all the traits of F₁ and F₂, the phenotypic coefficient of variation (PCV) was greater than the corresponding genotypic coefficient of variation (GCV), suggesting an influence of environment on the expression of these traits. Furthermore, high heritability along with high genetic advance in the percentage of the mean (GAM) was observed for all the traits studied except days to first flowering and plant height in F₁ and for grains panicle^-1, filled grains panicle^-1, grain yield panicle^-1, and grain yield plant^-1 in F₂ generations which is an indication of additive gene control and selection for improvement could be effective. Both the cross and reciprocal cross had significant positive heterosis with subsequent inbreeding depression predominantly in the number of tillers hill^-1, grains panicle^‑1, filled grains panicle^-1, grain yield panicle^-1, and grain yield plant^-1, excluding days to first flowering suggested the scope for exploitation of heterosis. Seed materials from F₂ generatios can be used to obtain advanced segregating generations for developing a high-yielding aromatic rice variety.