The genetic architecture of yield components and effective exploitation of a diverse gene pool are crucial to improve the productivity of wheat (Triticum aestivum L.). The related study aimed to tap the genetic potential and heterotic effects by crossing eight diverse wheat lines, i.e., Gulzar 19, Shahkar 13, Wadan 17, Fatehjang 16, Fahim 19, Pirsabak 19, Khaista 17, and Pirsabak 15 with four testers, viz., Zincol 16, Akbar 19, PR 128, and Zinc Shakthi. This line-by-tester mating design took place in 2022–2023 at the Cereal Crops Research Institute (CCRI), Pirsabak-Nowshera, Pakistan. Analysis of variance showed significant (p≤0.01) differences among genotypes, parents, crosses, and line-by-tester populations for most traits. Based on the mean performance, the F₁ wheat hybrid Gulzar 19 × Zincol 16 had the highest tiller count, grain spike^-1, biological yield, and grain yield. The general combining ability (GCA) to specific combining ability (SCA) variance ratios and degree of dominance implied non-additive gene action, suggesting delayed selection in F₂ generations. Zincol 16 showed positive GCA for tillers, grains spike⁻¹, biological yield, and grain yield; Akbar 19 also had positive GCA for 1000-grain weight; and PR 128 remained a common parent in multiple heterotic hybrids. Gulzar 19 × Zincol 16 had the highest SCA and heterosis for grain yield, proving it as the most promising candidate for future breeding.

Keywords: Bread wheat (T. aestivum L.), F₁ hybrids, line-by-tester mating design, heterosis, yield components, mean performance

Key findings: This study assessed eight lines and four testers to evaluate mean performance, combining abilities, gene action, and heterotic potential of wheat (T. aestivum L.) hybrids targeting at high-yielding wheat cultivars. Four F₁ hybrids (Gulzar 19 × Zincol 16, Pirsabak 19 × PR 128, Fahim 19 × PR 128, and Pirsabak 15 × Zincol 16) showed distinction for their superior performance in multiple traits for enhancing yield.