The identification and characterization of resistance genes should outpace the rapid emergence of new P. graminis f. sp. tritici races, such as TTRTF and TTKTT, to mitigate stem rust damage to wheat. The objective of the current study was to identify and characterize P. graminis f. sp. tritici race resistance association signals. A total of 250 North American spring wheat lines were evaluated at the seedling stage with a total of seven isolates including TKKTP, TKTTF, TKTTF, TRTTF, TTRTF, TTKSK, and TTKTT. The lines were genotyped by a GBS platform and 9,042 SNPs were used for identification of chromosome regions associated with resistance against the seven isolates. Strong association signals were detected on chromosomes 6BL (Sr11 gene region) and 4AL, likely Sr7a, for resistance against both TKKTP and TKTTF. Similarly, association signals were also detected on chromosomes 4AL (race TTRTF resistance) and 4BS (race TTKSK and TTKTT resistance). Association analysis based on mean phenotypic differences between closely related isolates identified QTL that were not elucidated by direct association mapping of the responses, individually. Overall, with the exception of race TRTTF, each race shared at least one association signal with another race. However, the number of race‐specific association signals are larger than that of association signals common among races suggesting the need for identifying and characterizing QTL/genes for newly emerging stem rust pathogen races. There was also high concordance between PCA‐based GWAS association signals and association signals from that of both single and multi‐locus mixed models.

中文翻译：

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基因组分型法对春小麦对新兴锈病病原菌抗性的关联图谱

抗性基因的鉴定和鉴定应该超过新的假单胞菌f。sp。TTRTF和TTKTT等小麦品种，以减轻小麦茎锈病的危害。本研究的目的是鉴定和表征体育粉虱。sp。Tritici种族抵抗协会信号。在苗期评估了总共250个北美春小麦品系，包括TKKTP，TKTTF，TKTTF，TRTTF，TTTRF，TTKSK和TTKTT在内的总共7个分离株。通过GBS平台对品系进行基因分型，并且使用9,042个SNP来鉴定与针对这七个分离物的抗性相关的染色体区域。在6BL号染色体（Sr11基因区域）和4AL，可能是Sr7a，用于抵抗TKKTP和TKTTF。同样，在4AL染色体（种族TTRTF抗性）和4BS（种族TTKSK和TTKTT抗性）上也检测到关联信号。基于密切相关的分离株之间的平均表型差异的关联分析确定了单独通过响应的直接关联映射无法阐明的QTL。总体而言，除了TRTTF种族外，每个种族与另一种族共享至少一个关联信号。但是，特定于种族的关联信号的数量大于种族之间常见的关联信号的数量，这表明需要为新兴的茎锈病病原体种族鉴定和表征QTL /基因。