Preliminary mapping of wheat (Triticum aestivum L.) tolerance genes to the English grain aphid (Sitobion avenae Fabricius) by genome-wide association study.

Abstract

Six Sitobion avenae-tolerant wheat accessions, mapped 110 associated SNPs and six candidate genes were identified, providing valuable genetic resources for breeding wheat with tolerance to S. avenae. Wheat tolerance to the English grain aphid (Sitobion avenae) is rarely incorporated into integrated pest management strategies for wheat fields. The scarcity of tolerant accession and insufficient mapping of tolerance-related gene are key limiting factors. To address these gaps, 640 wheat accessions were evaluated for S. avenae tolerance, combined with genome-wide association study (GWAS) and qPCR validation. Six wheat accessions with stable tolerance were identified: Lerma Rojo 64, AC Vista, Hanxuan 10, Zimai, Ningnuomai 1, Louguding. A total of 110 single nucleotide polymorphism (SNP) loci associated with tolerance to S. avenae were mapped, and six candidate genes (TraesCS2D03G0041800, TraesCS2Dnew048215, TraesCS2D03G0046300, TraesCS6B03G0655800, TraesCS2Dnew048223, TraesCS2D03G0040800) were examined for transcriptional responses following aphid infestation via qRT-PCR. These genes are involved in cellular redox homeostasis, ADP-binding-mediated defense, and photosystem II (PSII) functionality. This study provides valuable genetic resources for breeding wheat with tolerance to S. avenae and lays a foundation for subsequent functional validation of these tolerance genes and its molecular mechanism exploration.