Abstract

Resistance breeding is an effective strategy against wheat stripe (yellow) rust caused by Puccinia striiformis f. sp. tritici (Pst). To identify and map quantitative trait loci (QTL) associated with stripe rust resistance, a durum wheat doubled haploid population (n = 87) derived from ‘Strongfield/Blackbird’ was evaluated for disease severity near Toluca, Mexico (2017–2019) and Lethbridge, Canada (2016–2019). The population was genotyped with the wheat 90 K Illumina iSelect single nucleotide polymorphism (SNP) array and simple sequence repeat (SSR) markers, and QTL analysis was performed with MapQTL 6. We identified stripe rust-resistance QTL contributed by ‘Blackbird’ on chromosomes 3A (2 loci, designated QYr.spa-3A.1, QYr.spa-3A.2) and 5B (QYr.spa-5B), and ‘Strongfield’ on 2B (QYr.spa-2B). All seem to represent QTL not reported previously. The QYr.spa-3A.2 was most consistently effective against Pst races across the Lethbridge and Toluca nurseries. With a LOD value of 4.9, QYr.spa-3A.2 explained a maximum phenotypic variation of 22.7% observed at the Toluca 2019 nursery. The QYr.spa-2B from ‘Strongfield’ and QYr.spa-3A.1 from ‘Blackbird’ expressed in multiple years at Toluca but were not detected at Lethbridge. QYr.spa-5B was identified in the Lethbridge 2016 environment. The identified QTL should be valuable in diversifying resistance genes used in breeding durum wheat cultivars with stripe rust resistance. ‘Blackbird’ was particularly useful for introducing the new QTL QYr.spa-3A.2 resistance that is effective in Canada and Mexico into traditional durum wheat germplasm. SNP markers associated with QTL will have application in marker-assisted breeding of resistance to Pst in durum wheat.

摘要

抗性育种是针对由小麦条（黄色）锈的有效策略条锈菌F。sp. 小麦( Pst )。为了识别和绘制与条锈病抗性相关的数量性状基因座 (QTL)，在墨西哥托卢卡 (2017-2019) 和 Lethbridge 附近评估了源自“Strongfield/Blackbird”的硬粒小麦双单倍体种群 (n = 87) 的疾病严重程度, 加拿大 (2016–2019)。使用小麦 90 K Illumina iSelect 单核苷酸多态性 (SNP) 阵列和简单序列重复 (SSR) 标记对种群进行基因分型，并使用 MapQTL 6 进行 QTL 分析。我们在染色体上鉴定了由“黑鸟”贡献的抗条锈 QTL 3A（2 个基因座，指定为QYr.spa-3A.1、QYr.spa-3A.2) 和 5B ( QYr.spa-5B )，以及 2B ( QYr.spa-2B )上的“Strongfield” 。所有似乎都代表以前未报告的 QTL。该QYr.spa-3A.2是最一致反对有效的Pst跨越莱斯布里奇和托卢卡苗圃场比赛。LOD 值为 4.9，QYr.spa-3A.2解释了在 Toluca 2019 苗圃观察到的最大表型变异 22.7%。来自“Strongfield”的QYr.spa-2B和来自“Blackbird”的QYr.spa-3A.1在托卢卡多年表达，但在莱斯布里奇未检测到。QYr.spa-5B在 Lethbridge 2016 环境中发现。鉴定出的 QTL 对丰富抗条锈病硬粒小麦品种的抗性基因具有重要价值。'Blackbird' 对于将在加拿大和墨西哥有效的新 QTL QYr.spa-3A.2抗性引入传统硬粒小麦种质特别有用。与 QTL 相关的 SNP 标记将在标记辅助育种中应用硬质小麦Pst抗性。