Insights into Non-Additive Type of Gene Actionfor Grain Yield and Yield-Related Traitsin Wheat (<i>Triticum aestivum</i> L.)and its Breeding Implications

Line-by-tester combining ability analysis was carried out to investigate the heritable variations, GCA and SCA variances for lines (seven), testers (three), line tester F 2 populations (21), and inheritance of various morphological and yield traits in wheat.A randomized complete block design with three replications was utilized.Emasculation and pollen dusting was done manually.Analysis of variance revealed significant (p0.01)differences among all the studied parameters.Combining ability analysis discovered that lines had significant differences for the flag leaf area and 1000-grain weight.Testers were significant for 1000-grain weight and biological yield per plant.The ratio of variances due to GCA and SCA was smaller than unity, while the degree of dominance was greater than unity, which confirmed that all the traits were controlled by the non-additive gene effect.In proportional contribution, F 2 had the maximum share as compared to line and tester for five traits.For the flag leaf area, 1000-grain weight, the share of the parental line was leading as compared to testers and L T interaction.Heritability ranged from 0.68 to 0.97.Genetic gain values ranged from 1.65 to 8.83 g.Non-additive gene actions indicated that the selection of promising populations in terms of morphological and yield traits should be delayed until later segregating generations.Based on present findings, promising populations could be used in future breeding programs to develop high-yielding wheat genotypes.