|LU, YUE - Kansas State University|
|Bowden, Robert - Bob|
|ZHANG, GUORONG - Kansas State University Agricultural Research Center-Hays|
|FRITZ, ALLAN - Kansas State University|
Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2017
Publication Date: 8/18/2017
Citation: Lu, Y., Bowden, R.L., Zhang, G., Xu, X., Fritz, A., Bai, G. 2017. Quantitative trait loci for slow-rusting resistance to leaf rust in doubled-haploid wheat population CI13227 × Lakin. Journal of Phytopathology. https://doi.org/10.1094/PHYTO-09-16-0347-R.
Interpretive Summary: Wheat leaf rust is an important wheat disease worldwide. Growing resistant cultivars is the most effective approach to defeat the disease. Cultivars that carry slow rusting resistance can last a long time without being overcome by new rust races. The objective of this study is to identify slow rusting resistance genes in winter wheat line CI13227. We constructed a linkage map using markers from a cross of CI13227 with Lakin, which is a susceptible cultivar. Four genes for slow rust resistance were identified on chromosomes 2D, 7B, 7A and 3B. The one on 2D showed the consistently largest effect on slow rusting traits. The gene on the chromosome 7B was located on the same location as Lr68. The other two genes showed a minor effect on the slow rusting traits. DNA markers developed in this study can be used for marker-assisted breeding.
Technical Abstract: Wheat leaf rust, caused by Puccinia triticina, is an important wheat disease worldwide. Deployment of resistant cultivars is a common practice to reduce the losses caused by the disease, and using slow rusting resistance genes can improve durability of rust resistance in the cultivars. To identify quantitative trait loci (QTLs) for slow-rusting traits in a winter wheat line CI13227, a linkage map was constructed using 6415 single nucleotide polymorphism (SNP) markers derived from wheat 90K SNP assays and 84 simple sequence repeat (SSR) markers and a doubled haploid (DH) population from CI13227 × Lakin. Four QTLs were identified for four slow-rusting traits on chromosomes 2D, 7B, 7A and 3B. The QTL on 2D is a major QTL that was significant for all four traits measured in both experiments and explained 11.2 to 25.6% of the phenotypic variation for different traits. The QTL on the chromosome 7B was significant for area under disease progress curve (AUDPC) in both experiments, and explained 8.1 and 19.3% of the phenotypic variation, but was only significant in one experiment for final severity (FS), infection type (IT), and latent period (LP). The other two QTLs on chromosomes 7A and 3B showed a minor effect on some of the traits evaluated in a single experiment. Flanking SNPs closely linked to the four QTLs were identified and converted to breeder-friendly Kompetitive allele-specific polymorphism (KASP) markers that can be used in marker-assisted selection to transfer these QTLs into adapted wheat cultivars.