Many of the major stem rust resistance genes deployed in commercial wheat (Triticum spp.) cultivars and breeding lines become ineffective over time because of the continuous emergence of virulent races. A genome-wide association study (GWAS) was conducted using 26,439 single nucleotide polymorphism (SNP) markers and 280 durum wheat [Triticum turgidum L. subsp. Durum (Desf.) Husnot] lines from CIMMYT to identify genomic regions associated with seedling resistance to races TTKSK, TKTTF, JRCQC, and TTRTF and field resistance to TKTTF and JRCQC. The phenotypic data analysis across environments revealed 61–91 and 59–77% of phenotypic variation was explained by the genotypic component for seedling and adult plant response of lines, respectively. For seedling resistance, mixed linear model (MLM) identified eight novel and nine previously reported quantitative trait loci (QTL) while a fixed and random model circulating probability unification (FarmCPU) detected 12 novel and eight previously reported QTL. For field resistance, MLM identified 12 novel and seven previously reported loci while FarmCPU identified seven novel and nine previously reported loci. The regions of Sr7a, Sr8155B1, Sr11, alleles of Sr13, Sr17, Sr22/Sr25, and Sr49 were identified. Novel loci on chromosomes 3B, 4A, 6A, 6B, 7A, and 7B could be used as sources of resistance to the races virulent on durum wheat. Two large-effect markers on chromosome 6A could potentially be used to differentiate resistant haplotypes of Sr13 (R1 and R3). Allelism tests for Sr13, breaking the deleterious effect associated with Sr22/Sr25 and retaining the resistance allele at the Sr49 locus, are needed to protect future varieties from emerging races.

中文翻译：

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硬质小麦面板中幼苗和成株对茎锈病反应的全基因组关联图

由于有毒小种的不断出现，商业小麦（小麦属）栽培品种和育种品系中部署的许多主要茎锈病抗性基因随着时间的推移变得无效。使用 26,439 个单核苷酸多态性 (SNP) 标记和 280 个硬粒小麦 [ Triticum turgidum L. subsp. ]进行了全基因组关联研究 (GWAS) 。杜伦麦(Desf.) Husnot] 来自 CIMMYT 的品系，用于鉴定与幼苗对 TTKSK、TKTTF、JRCQC 和 TTRTF 和田间对 TKTTF 和 JRCQC 的抗性相关的基因组区域。跨环境的表型数据分析显示，61-91% 和 59-77% 的表型变异分别由品系的幼苗和成株反应的基因型成分解释。对于幼苗抗性，混合线性模型 (MLM) 确定了 8 个新的和 9 个先前报告的数量性状基因座 (QTL)，而固定和随机模型循环概率统一 (FarmCPU) 检测到了 12 个新的和 8 个先前报告的 QTL。对于田间抗性，MLM 确定了 12 个新的和 7 个先前报告的基因座，而 FarmCPU 确定了 7 个新的和 9 个先前报告的基因座。Sr7a的区域，鉴定了 Sr8155B1、Sr11、Sr13、Sr17、Sr22/Sr25和Sr49 的等位基因。染色体 3B、4A、6A、6B、7A 和 7B 上的新基因座可用作对硬粒小麦毒性小种的抗性来源。6A 号染色体上的两个大效应标记可能用于区分Sr13（R1 和 R3）的抗性单倍型。需要对Sr13进行等位基因测试，打破与Sr22/Sr25相关的有害影响并保留Sr49基因座的抗性等位基因，以保护未来品种免受新兴种族的影响。