Spot blotch (SB), caused by Bipolaris sorokiniana, is a devastating disease of wheat globally, especially in South Asia and South America. Understanding the genetics of resistance to SB is important for developing breeding strategies to improve resistance. A panel of 301 genotypes from Afghanistan was phenotyped over two crop seasons using a mixture of virulent B. sorokiniana isolates and genotyped using DArTSeq to obtain genome‐wide markers. Fifty genotypes (16.6%) showed disease scores less than the resistant control. Principal component analysis using the genotypic data clustered the genotypes into five different groups. Among models used for genome‐wide association mapping, the multilocus mixed model, and fixed and random model circulating probability unification algorithms were most effective in identifying significant marker‐trait associations (MTA). Twenty‐five MTAs at p ≤ .001 were identified on chromosomes 1A, 1B, 1D, 2B, 2D, 3A, 3B, 4A, 5A, 5B, 6A, 7A, and 7D, indicating the quantitative nature of resistance to SB. Phenotypic variation explained by these markers ranged from 2.0% to 17.7%, and genomic regions on the chromosomes 1D, 2D, 3A, 3B, 4A, 5A, and 5B coincided with loci identified in previous studies. Three single nucleotide polymorphism (SNP) markers on chromosomes 1B (SNP 1113207) and 5A (SNPs 5411867 and 998276) were significant in both crop seasons as well as in the combined analysis across seasons. Marker 5411867 is close to Vrn‐A1, shown to be associated with SB in previous studies. Furthermore, among known SB resistance genes, Sb2 on chromosome 5B was predicted to be significant in this panel.

中文翻译：

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阿富汗小麦种质抗斑点病的全基因组关联研究

斑点斑病 (SB) 是由双极性小麦引起的，是全球小麦的一种毁灭性病害，尤其是在南亚和南美洲。了解 SB 抗性的遗传学对于制定提高抗性的育种策略很重要。使用有毒 B. sorokiniana 分离株的混合物在两个作物季节对来自阿富汗的一组 301 种基因型进行表型分析，并使用 DArTSeq 进行基因分型以获得全基因组标记。50 个基因型 (16.6%) 显示疾病评分低于抗性对照。使用基因型数据的主成分分析将基因型分为五个不同的组。在用于全基因组关联作图的模型中，多位点混合模型、固定和随机模型循环概率统一算法在识别显着的标记性状关联 (MTA) 方面最有效。在染色体 1A、1B、1D、2B、2D、3A、3B、4A、5A、5B、6A、7A 和 7D 上鉴定出 25 个 p ≤ .001 的 MTA，表明对 SB 的抗性的定量性质。这些标记解释的表型变异范围从 2.0% 到 17.7%，染色体 1D、2D、3A、3B、4A、5A 和 5B 上的基因组区域与先前研究中确定的基因座一致。染色体 1B (SNP 1113207) 和 5A (SNP 5411867 和 998276) 上的三个单核苷酸多态性 (SNP) 标记在两个作物季节以及跨季节的组合分析中都很显着。标记 5411867 与 Vrn-A1 接近，在之前的研究中显示与 SB 相关。此外，