Graphical and Numerical Analysis of the Components of Gene Effect on the Quality Traits of Bread Wheat (Triticum aestivum L.) under Varying Environmental Conditions

Abstract

Wheat is one of the main cereals. At this time, the crucial difficulty in improving nutritional traits is the influence on genotypes of different environments. Selecting superior genotypes on the basis of a gene effects analysis for varying environments is demanded. In this study, 10 different genotypes of bread wheat (Triticum aestivum L.) were used. Parents, hybrids, and two standard checks were evaluated in a complete randomized block design with three replicates in four environments: E1 and E2 (normal and late sown, Rabi 2018-19) & E3 and E4 (normal and late sown, Rabi 2019-20). The analysis of the components of the gene effect revealed that most of the characters were governed by additive and dominant gene actions in the environments; for gluten, the wet gluten (E2) and starch (E3) content were the only dominant components (H1 and H2) with a significant gene effect. Overdominance, asymmetrical distribution of positive–negative and dominant–recessive genes, and narrow-sense heritability were observed in most of the characters in all environments. In a graphical analysis, the regression value b was observed to be in unity among protein content (E1 and E3), sedimentation value (E1, E2, and E3), and starch content (E1), indicating the absence of digenic interactions. Based on the intercept of the regression line on the Wr axis, the degree of dominance for protein content (E1 and E3), sedimentation value (E1, E2, and E3), and starch content (E1) was depicted as overdominance. Therefore, a given population may be improved to isolate superior recombinants for the development of desired parents in future breeding programs.