NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK.
Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
Theor Appl Genet. 2022 Jan;135(1):301-319. doi: 10.1007/s00122-021-03967-z. Epub 2021 Nov 27.
Analysis of a wheat multi-founder population identified 14 yellow rust resistance QTL. For three of the four most significant QTL, haplotype analysis indicated resistance alleles were rare in European wheat. Stripe rust, or yellow rust (YR), is a major fungal disease of wheat (Triticum aestivum) caused by Puccinia striiformis Westend f. sp. tritici (Pst). Since 2011, the historically clonal European Pst races have been superseded by the rapid incursion of genetically diverse lineages, reducing the resistance of varieties previously showing durable resistance. Identification of sources of genetic resistance to such races is a high priority for wheat breeding. Here we use a wheat eight-founder multi-parent population genotyped with a 90,000 feature single nucleotide polymorphism array to genetically map YR resistance to such new Pst races. Genetic analysis of five field trials at three UK sites identified 14 quantitative trait loci (QTL) conferring resistance. Of these, four highly significant loci were consistently identified across all test environments, located on chromosomes 1A (QYr.niab-1A.1), 2A (QYr.niab-2A.1), 2B (QYr.niab-2B.1) and 2D (QYr.niab-2D.1), together explaining ~ 50% of the phenotypic variation. Analysis of these four QTL in two-way and three-way combinations showed combinations conferred greater resistance than single QTL, and genetic markers were developed that distinguished resistant and susceptible alleles. Haplotype analysis in a collection of wheat varieties found that the haplotypes associated with YR resistance at three of these four major loci were rare (≤ 7%) in European wheat, highlighting their potential utility for future targeted improvement of disease resistance. Notably, the physical interval for QTL QYr.niab-2B.1 contained five nucleotide-binding leucine-rich repeat candidate genes with integrated BED domains, of which two corresponded to the cloned resistance genes Yr7 and Yr5/YrSp.
分析一个小麦多亲本群体，鉴定出 14 个抗黄锈病 QTL。对于四个最重要的 QTL 中的三个，单倍型分析表明，欧洲小麦中抗性等位基因很少。条锈病，又称黄锈病（YR），是小麦（Triticum aestivum）的一种主要真菌病害，由条形柄锈菌（Puccinia striiformis Westend f. sp. tritici）（Pst）引起。自 2011 年以来，历史上无性繁殖的欧洲 Pst 菌系已被遗传上多样化的谱系迅速取代，降低了以前表现出持久抗性的品种的抗性。鉴定对这些菌系具有遗传抗性的来源是小麦育种的首要任务。在这里，我们使用一个小麦八亲本多亲本群体，该群体用 90000 个特征单核苷酸多态性阵列进行基因分型，对这种新的 Pst 菌系的 YR 抗性进行遗传作图。在英国三个地点的五个田间试验的遗传分析确定了 14 个赋予抗性的数量性状位点（QTL）。其中，四个高度显著的位点在所有测试环境中均一致鉴定，位于染色体 1A（QYr.niab-1A.1）、2A（QYr.niab-2A.1）、2B（QYr.niab-2B.1）和 2D（QYr.niab-2D.1）上，共同解释了约 50%的表型变异。对这些四个 QTL 的双向和三向组合分析表明，组合比单个 QTL 赋予更大的抗性，并且开发了区分抗性和易感等位基因的遗传标记。在一个小麦品种集合中的单倍型分析发现，在这四个主要位点中的三个位点与 YR 抗性相关的单倍型在欧洲小麦中很少见（≤7%），突出了它们在未来有针对性地提高抗病性方面的潜在应用。值得注意的是，QTL QYr.niab-2B.1 的物理区间包含五个核苷酸结合富含亮氨酸重复候选基因，其中两个对应于已克隆的抗性基因 Yr7 和 Yr5/YrSp。
