Deciphering Genetic Diversity and Gene Action in Barley Using Line × Tester Mating Design to Enhance Yield Attributes

Abstract

Using a line × tester mating approach, the study sought to investigate the combining ability of barley (Hordeum vulgare L.) for important yield-related variables. For the majority of attributes, there were notable changes between the parents, hybrids, and their interactions, demonstrating the significant genetic diversity and efficacy of the selected breeding strategy. For parameters including plant height, spike length, grains per spike, tillers per plant, 1000-grain weight, and grain yield per plant, general combining ability (GCA) variants were greater than specialized combining ability (SCA) variances, suggesting the predominance of additive gene activity. Significant SCA effects, however, highlighted the importance of non-additive gene action for several characteristics and raised the possibility of heterosis exploitation. The crosses L5×T3 and L7×T4 exhibited significant positive SCA effects for grains per spike and grain yield per plant, whereas line L3 and tester T3 showed the strongest positive GCA effects for plant height and spike length, respectively. The findings underscore the significance of additive and non-additive gene activities in barley breeding and show that careful parent selection and hybridization can result in superior hybrids with higher yield potential.