Genetic Behavior of Yield and Component Traits in Bread Wheat (Triticum aestivum L.)

Abstract

The present investigation was undertaken to assess the extent of genetic variability, heritability, and genetic advance among early-sown wheat genotypes for yield and related traits. The experiment was laid out in a Randomized Block Design (RBD) with three replications, comprising 65 genotypes including 15 parents (5 males and 10 females) and 50 hybrids derived from a Line × Tester mating design. The study was conducted at the Zonal Agricultural Research Station, Powarkheda, Hoshangabad (Madhya Pradesh), India, during the rabi seasons of 2019–20 and 2020–21. All genotypes were evaluated for sixteen agronomic and physiological traits. Analysis of variance (ANOVA) was performed to assess genetic variability, while genotypic and phenotypic coefficients of variation (GCV and PCV), broad-sense heritability (H²), and genetic advance (GA) were estimated to determine the nature and extent of genetic control. ANOVA revealed highly significant differences among genotypes for all traits, confirming the presence of substantial genetic variability. A close correspondence between GCV and PCV across most traits indicated minimal environmental influence and strong genetic control. Broad-sense heritability estimates were notably high, ranging from 83.10% (peduncle length) to 99.90% (biological yield). Traits such as grain yield per plant (H² = 99.40%), biological yield (99.90%), harvest index (98.90%), number of effective tillers per plant (94.30%), and number of spikes per plant (96.60%) exhibited high heritability coupled with high genetic advance (GA% = 58.66%, 68.18%, 51.82%, 50.50%, and 38.27%, respectively), indicating the predominance of additive gene action. In contrast, traits like peduncle length, canopy temperature, and 1000-grain weight showed high heritability but moderate genetic advance, suggesting a combination of additive and non-additive gene effects. The study highlights the predominance of additive genetic variance in most traits, indicating that direct phenotypic selection would be effective for yield improvement. For traits governed by both additive and non-additive gene effects, hybridization strategies could be more suitable. These findings provide a strong genetic foundation for developing high-yielding, early-sown, and climate-resilient wheat cultivars under Central Indian conditions.