Abstract

This study was conducted to identify and map stem rust resistance genes in Canada Western Red Spring (CWRS) wheat variety ‘AAC Prevail’ and elite line ‘BW961ʹ. A population of 227 doubled haploid lines from ‘AAC Prevail’/‘BW961ʹ and parents were evaluated for their response to stem rust (Puccinia graminis) at Njoro, Kenya, from 2016–2019 and genotyped using a targeted genotyping by sequencing SeqSNP assay. ‘AAC Prevail’ and ‘BW961ʹ were susceptible to race TTKSK in seedling tests in Canada. We identified stable QTL (significant in most environments tested) associated with field stem rust resistance on chromosome arms 2BS and 7AL, and minor QTL on 5AL, 6AS and 7BL. The QTL on 5AL, 7AL and 7BL were contributed by ‘AAC Prevail’, while those on 2BS and 6AS were contributed by ‘BW961ʹ. The QTL on 7AL was detected across all environments and explained 9.5% to 39% of the variation in disease severity (DS) and infection response (IR). The QTL on 2BS was associated with DS in all environments and in three of four environments for IR, and explained 4.8% to 12% of the variation in DS and IR. In two environments, the combination of 2BS and 7AL significantly enhanced field stem rust resistance compared with either QTL singly. Using SNP markers closely linked to the novel QTL on 2BS and 7AL, Kompetitive Allele Specific PCR markers were developed and validated in the population. These results provide breeders with new information and markers to utilize these sources of stem rust resistance.

摘要

本研究旨在鉴定和定位加拿大西部红春 (CWRS) 小麦品种 'AAC Prevail' 和优良品系 'BW961ʹ 的茎锈病抗性基因。评估了来自 'AAC Prevail'/'BW961' 的 227 个双单倍体系及其亲本对茎锈病（Puccinia graminis) 于 2016 年至 2019 年在肯尼亚 Njoro，并通过测序 SeqSNP 测定使用靶向基因分型进行基因分型。'AAC Prevail' 和 'BW961' 在加拿大的幼苗试验中易受 TTKSK 种的影响。我们在染色体臂 2BS 和 7AL 上确定了与田间茎锈病抗性相关的稳定 QTL（在大多数测试环境中显着），以及在 5AL、6AS 和 7BL 上的次要 QTL。5AL、7AL和7BL的QTL由'AAC Prevail'贡献，而2BS和6AS的QTL由'BW961ʹ贡献。在所有环境中都检测到 7AL 上的 QTL，并解释了疾病严重程度 (DS) 和感染反应 (IR) 9.5% 到 39% 的变化。2BS 上的 QTL 与所有环境中的 DS 以及 IR 的四个环境中的三个环境中的 DS 相关，并解释了 DS 和 IR 变异的 4.8% 至 12%。在两种环境中，2BS和7AL的组合与单独的QTL相比显着提高了田间茎锈病的抗性。使用与 2BS 和 7AL 上的新型 QTL 密切相关的 SNP 标记，在人群中开发并验证了竞争性等位基因特异性 PCR 标记。这些结果为育种者提供了新的信息和标记，以利用这些茎锈病抗性来源。