Dissection of loci conferring resistance to stripe rust in Chinese wheat landraces from the middle and lower reaches of the Yangtze River via genome-wide association study.

Research paper by Yukun Y Cheng, Jian J Li, Fangjie F Yao, Li L Long, Yuqi Y Wang, Yu Y Wu, Jing J Li, Xueling X Ye, Jirui J Wang, Qiantao Q Jiang, Houyang H Kang, Wei W Li, Pengfei P Qi, Yaxi Y Liu, Mei M Deng, et al.

Indexed on: 30 Oct '20Published on: 05 Sep '19Published in: Plant Science


Stripe rust (Yr), caused by the fungal pathogen Puccinia striiformis f. sp. tritici, is a devastating foliar disease of wheat in China. Chinese wheat landraces originating from the middle and lower reaches of the Yangtze River are potential stripe-rust resistance resources. To identify APR genes for stripe-rust resistance, a panel of 188 accessions derived from the middle and lower reaches of the Yangtze River were inoculated with a mixture of Chinese P. striiformis f. sp. tritici races and resistance evaluated under field conditions in five environments at adult-plant stages. Seventy-three accessions showed degrees of stable resistance. Combining phenotypic datasets from multiple field experiments with high-quality Diversity Arrays Technology and simple sequence repeat markers, we detected 21 marker-trait associations spanning 18 quantitative trait loci (QTLs) on chromosomes 1B, 2A, 2B, 3B, 4A, 5A, 5B, 6B, and 6D, respectively. Single QTLs explained 9.67% to 16.14% of the observed phenotypic variation. Nine QTLs co-localized with previously reported Yr genes or genomic regions. The remaining QTLs were potential novel loci associated with adult-stage stripe-rust resistance. Two novel QTLs, QYr.sicau-3B.2 and QYr.sicau-5B.3, located on chromosomes 3B and 5B significantly explained 16.14% and 11.16% of the phenotypic variation, respectively. Haplotype analysis revealed that accessions carrying APR variants or their combinations showed enhanced degrees of resistance. The potentially novel loci or genomic regions associated with adult-stage resistance may be useful to improve stripe-rust resistance in current wheat cultivars and for future isolation of stripe-rust resistance genes. Copyright © 2019 Elsevier B.V. All rights reserved.

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