Studies on combining ability for yield, its components and zinc content in rice (Oryza sativa L.)

Abstract

A line x tester analysis was performed using three lines and eight testers, generating 24 hybrids, to evaluate the combining ability of parents for grain yield, yield-contributing traits, and zinc content in rice. Twelve traits were studied: days to 50% flowering, plant height (cm), panicle length (cm), effective tillers per plant, grains per panicle, length-to-breadth ratio, grain yield per plant (g), straw yield per plant (g), test weight (g), zinc content (ppm), protein content (%), and amylose content (%). The experiment was conducted in a randomized block design (RBD) with three replications at the Main Rice Research Station, Navsari Agricultural University, Navsari, during kharif 2024. The analysis of variance for combining ability indicated that general combining ability (σ²GCA) effects were significant for grains per panicle, while specific combining ability (σ²SCA) effects were significant for all traits except plant height and zinc content. The σ²GCA/σ²SCA ratio was less than one for all traits, suggesting that non-additive genetic variance played a predominant role in their inheritance.