Identification of new resistance loci against wheat sharp eyespot through genome-wide association study

Xujiang Wu; Junchan Wang; Di Wu; Wei Jiang; Zhifu Gao; Dongsheng Li; Rongling Wu; Derong Gao; Yong Zhang

doi:10.3389/fpls.2022.1056935

Identification of new resistance loci against wheat sharp eyespot through genome-wide association study

Front Plant Sci. 2022 Dec 12:13:1056935. doi: 10.3389/fpls.2022.1056935. eCollection 2022.

Authors

Xujiang Wu^{1

2

3

4}, Junchan Wang¹, Di Wu¹, Wei Jiang¹, Zhifu Gao¹, Dongsheng Li¹, Rongling Wu¹, Derong Gao^{1

2

3

4}, Yong Zhang^{1

2

3

4}

Affiliations

¹ Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou, China.
² Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region, Ministry of Agriculture, Yangzhou, China.
³ Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
⁴ Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China.

Abstract

Introduction: Wheat sharp eyespot caused by Rhizoctonia cerealis is a serious pathogenic disease affecting plants. The effective strategy for controlling this disease is breeding resistant cultivar. However, to date, no wheat varieties are fully resistant to sharp eyespot, and only a few quantitative trait loci (QTLs) have been shown to be associated with sharp eyespot resistance.

Methods: To understand the genetic basis of this disease, a genome-wide association study (GWAS) of sharp eyespot resistance in 262 varieties from all China wheat regions was conducted.

Results: After cultivation for three years, only 6.5% of the varieties were resistant to sharp eyespot. Notably, the varieties from the middle and lower Yangtze River displayed higher sharp eyespot resistance than those from Huanghuai wheat zone. Only two varieties had the same resistance level to the control Shanhongmai. The results of GWAS showed that 5 single nucleotide polymorphism (SNP) loci were markedly related to sharp eyespot resistance in the three years repeatedly, and two QTLs, qSE-6A and qSE-7B, on chromosome 6A and 7B were identified. Based on the 'CG' haplotypes of significant SNPs, we found that the two QTLs exhibited additive effects on attenuating sharp eyespot resistance.

Discussion: These results provide novel insights into the genetic basis of sharp eyespot resistance in China wheat varieties. The SNPs related to sharp eyespot resistance can be applied for marker-assisted selection in plant breeding.

Keywords: genome-wide association study (GWAS); quantitative trait loci (QTL); sharp eyespot; single nucleotide polymorphism (SNP); wheat.