Genome-wide association analysis of stripe rust resistance loci in wheat accessions from southwestern China

Bin Cheng,Yanqing Ding,Liyi Zhang,Tianqing Chen,Yu Gao,Xu Gao,Ning Cao,Zhihai Xin

doi:10.1007/s13353-019-00533-8

Bin Cheng, Yanqing Ding + Show 6 more

Open Access

https://doi.org/10.1007/s13353-019-00533-8

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Abstract

Wheat stripe rust can cause considerable yield losses, and genetic resistance is the most effective approach for controlling the disease. To identify the genomic regions responsible for Puccinia striiformis f. sp. tritici (Pst) resistance in a set of winter wheat strains mainly from southwestern China, and to identify DNA markers in these regions, we carried out a genome-wide association study (GWAS) of 120 China winter wheat accessions using single nucleotide polymorphism (SNP) markers from 90K wheat SNP arrays. In total, 16 SNP loci were significantly associated with wheat stripe rust in field and greenhouse trials. Of these, three distinctive SNPs on chromosomes 1B, 4A, and 6A were identified at a site in Mianyang in 2014, where the most prevalent wheat stripe rust races since 2009 have been V26 (G22-9, G22-14). This suggests that the three SNP loci were linked to the new quantitative trait loci (QTL)/genes resistant to the V26 races. Germplasm with immunity to Pst is a good source of stripe rust resistance for breeding, and after further validation, SNPs closely linked to resistance QTLs/genes could be converted into user-friendly markers and facilitate marker-assisted selection to improve wheat stripe rust resistance.

Highlights

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive fungal diseases, causing significant grain yield losses under severe infections in wheat fields where high levels of moisture (Solh et al 2012)
Germplasm with immunity to Pst is a good source of stripe rust resistance for breeding, and after further validation, single nucleotide polymorphism (SNP) closely linked to resistance quantitative trait loci (QTL)/genes could be converted into userfriendly markers and facilitate marker-assisted selection to improve wheat stripe rust resistance
The highest percentage of accessions (80.0%) with resistance to stripe rust was observed in Guiyang in 2014, while the lowest occurred in Mianyang in 2014 (56.8%) and Guiyang in 2013 (54%)

Summary

Introduction

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most destructive fungal diseases, causing significant grain yield losses under severe infections in wheat fields where high levels of moisture (Solh et al 2012). Approximately 83 officially designed (Yr1–78) and 47 temporarily named stripe rust resistance genes have been identified in wheat and its wild relatives (McIntosh et al 2014; Maccaferri et al 2015; McIntosh et al 2017). These resistance genes have been mapped to various chromosomes. The V26 pathogen has spread to several major wheat-producing areas and constitutes a great threat to wheat production in China. It is essential to discover new genes for stripe rust resistance and incorporate them into elite wheat germplasms to protect them against this devastating disease

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