Characterization of quantitative trait loci for leaf rust resistance from CI 13227 in three winter wheat populations

Authors: ZHAO, LANFEI - Kansas State University; LU, YUE - Kansas State University; ZHANG, XIAOCHUN - Kansas State University; ZHAO, WEI - Kansas State University; Xu, Xiangyang; Wang, Hongliang; ZHANG, GUORONG - Kansas State University; FRITZ, ALLAN - Kansas State University; Fellers, John; Guttieri, Mary; Jordan, Katherine; Bai, Guihua

Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2024
Publication Date: 6/3/2024
Citation: Zhao, L., Lu, Y., Zhang, X., Zhao, W., Xu, X., Wang, H., Zhang, G., Fritz, A., Fellers, J.P., Guttieri, M.J., Jordan, K., Bai, G. 2024. Characterization of quantitative trait loci for leaf rust resistance from CI 13227 in three winter wheat populations. Journal of Phytopathology. phyto-03-24-0108-r. https://doi.org/10.1094/PHYTO-03-24-0108-R.
DOI: https://doi.org/10.1094/PHYTO-03-24-0108-R

Interpretive Summary: Leaf rust is a severe wheat foliar disease worldwide. Slow-rusting confers “adult plant” resistance that can significantly slow down rust epidemics to reduce yield losses. Wheat accession CI 13227 has slow-rusting resistance and was studied for slow-rusting resistance. Three quantitative trait loci (QTL) were identified from CI 13227, explaining 6.82 to 28.45% of the phenotypic variance. Two of them were mapped at the same locations as in previous studies and one QTL was remapped from chromosome 7A to 2BL (QLr.hwwg-2BL)after adding new markers in this study. The QTL on chromosome arm 2DS showed a major effect on rusting traits, and was finely mapped to a 2.7 Mb interval, Molecular markers developed and validated in this study can be used for selecting those QTL in breeding.

Technical Abstract: Leaf rust is a widespread foliar wheat disease causing substantial yield losses worldwide. Slow-rusting is “adult plant” resistance that significantly slows epidemic development and thereby reduces yield loss. Wheat accession CI 13227 was previously characterized as having slow-rusting resistance. To validate the quantitative trait loci (QTL) and develop diagnostic markers for slow rusting resistance in CI 13227, a new population of recombinant inbred lines (RILs) of CI 13227 × Everest was evaluated for latent period (LP), final severity (FS), area under disease progress curve (AUDPC), and infection type (IT) in greenhouses and genotyped using genotyping-by-sequencing (GBS). Four QTL were identified on chromosome arms 2BL, 2DS, 3BS, and 7BL, explaining 6.82 to 28.45% of the phenotypic variance for these traits. Seven kompetitive allele specific polymorphism (KASP) markers previously reported to be linked to the QTL in two other CI 13227 populations were validated. In addition, the previously reported QLr.hwwg-7AL was remapped to 2BL (renamed QLr.hwwg-2BL) after adding new markers in this study. Phenotypic data showed that the RILs harboring two or three of the QTL had a significantly longer LP. QLr.hwwg-2DS on 2DS showed a major effect on all rust resistance traits and was finely mapped to a 2.7 Mb interval by two newly developed flanking markers from exome capture. Three disease-resistance genes and two transporter genes were identified as the putative candidates for QLr.hwwg-2DS. The validated QTL can be used as slow rusting resistance resources and the markers developed in this study will be useful for marker-assisted selection.