Evaluation of Heritability and Genetic Advance for Yield and Yield Attributes Using Line × Tester Derived Generations in Wheat (Triticum aestivum L.)

Abstract

Heritability is a key metric in quantitative genetics that reflects the proportion of total phenotypic variability that is determined by genetic components. Traits exhibiting high heritability are more amenable to successful selection, whereas those with low heritability are largely influenced by environmental factors. The objective was to determine heritability levels, estimate genetic advance, and pinpoint traits amenable to improvement through early or delayed selection, thereby facilitating the development of high-yielding and genetically diverse wheat cultivars. The study was conducted at the SIF Farm, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, during rabi season of 2023-24. Ten lines and five testers were crossed using a line × tester mating design to evaluate selection parameters i.e. heritability and genetic advance in F₁ and F₂ generations. Heritability estimates varied widely, with high heritability in both generation F1 and F2 observed for biological yield per plant, while the remaining traits showed moderate to low heritability, indicating strong environmental influence. Genetic advance as percent of mean (GA%) revealed high values for the number of productive tillers per plant, biological yield per plant, and seed yield per plant in both generations, indicating additive gene action. Low heritability with low GA% for number of productive tillers per plant, number of spikelets per spike, number of grains per spike, 1000 grain weight, protein content and seed hardness indicated minimal response to direct selection. The findings emphasize that yield and major yield components can be effectively improved by selection in later generations, while traits strongly influenced by the environment require alternative breeding strategies.