Identification of Elite Wheat Genotypes for Leaf Rust Resistance in a Geographically Diverse Wheat Panel Using Line × Tester Analysis

Abstract

Leaf rust (LR) poses a global threat to wheat crops and can lead to severe yield losses if environmental conditions favour its spread. Using resistant wheat cultivars offers a sustainable approach to managing LR. This study aimed to identify promising wheat lines for LR-resistance breeding using classical analytical methods to screen for LR tolerance. We evaluated 10 parental lines, comprising 6 lines and 4 testers, crossed into 24 combinations using a line × tester mating design. These germplasm were grown in a triplicate RCB design under both optimal and LR-stress conditions. We recorded data on various morphological, physiochemical, yield and component traits at key growth stages. The analysis of combining ability indicated significant variations among genotypes, with non-additive gene action influencing most traits. Four promising parents (AN179, AN1687, PR123 and PR127) and two crosses (AN179 × PR127 and AN179 × PR123) showed high combining ability for yield traits under LR-stress. Cluster analysis revealed divergent groups among the genotypes, with shifting clustering under LR-stress suggesting varied genotypic responses. Factor analysis identified genotypes that performed consistently well under LR-stress. These genotypes are suitable for use in LR-resistance breeding programs. We also recommend peduncle length and tillers per plant as phenotypic markers for wheat selection and breeding due to their positive correlation with grain yield. The findings of this study can contribute valuable insights to sustainable wheat breeding research.