Department of Plant Sciences, North Dakota State University, Fargo, ND, 58105, USA.
Department of Plant Pathology, North Dakota State University, Fargo, ND, 58105, USA.
Theor Appl Genet. 2024 Nov 13;137(12):265. doi: 10.1007/s00122-024-04767-x.
Robust QTLs conferring resistance to bacterial leaf streak in wheat were mapped on chromosomes 3B and 5A from the variety Boost and on chromosome 7D from the synthetic wheat line W-7984. Bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa poses a significant threat to global wheat production. High levels of BLS resistance are rare in hexaploid wheat. Here, we screened 101 diverse wheat genotypes under greenhouse conditions to identify new sources of BLS resistance. Five lines showed good levels of resistance including the wheat variety Boost and the synthetic hexaploid wheat line W-7984. Recombinant inbred populations derived from the cross of Boost × ND830 (BoostND population) and W-7984 × Opata 85 (ITMI population) were subsequently evaluated in greenhouse and field experiments to investigate the genetic basis of resistance. QTLs on chromosomes 3B, 5A, and 5B were identified in the BoostND population. The 3B and 5A QTLs were significant in all environments, but the 3B QTL was the strongest under greenhouse conditions explaining 38% of the phenotypic variation, and the 5A QTL was the most significant in the field explaining up to 29% of the variation. In the ITMI population, a QTL on chromosome 7D explained as much as 46% of the phenotypic variation in the greenhouse and 18% in the field. BLS severity in both populations was negatively correlated with days to heading, and some QTLs for these traits overlapped, which explained the tendency of later maturing lines to have relatively higher levels of BLS resistance. Markers associated with the QTLs were converted to KASP markers, which will aid in the deployment of the QTLs into elite lines for the development of BLS-resistant wheat varieties.
在小麦品种 Boost 的 3B 和 5A 染色体以及合成小麦品系 W-7984 的 7D 染色体上定位到赋予对细菌性条斑病抗性的强壮 QTL。由黄单胞菌属烟草致病变种引起的细菌性条斑病（BLS）对全球小麦生产构成重大威胁。在六倍体小麦中，BLS 抗性水平很高的情况很少见。在这里，我们在温室条件下筛选了 101 种不同的小麦基因型，以鉴定新的 BLS 抗性来源。包括小麦品种 Boost 和合成六倍体小麦品系 W-7984 在内的 5 个品系表现出良好的抗性水平。随后，从 Boost × ND830（BoostND 群体）和 W-7984 × Opata 85（ITMI 群体）杂交中衍生的重组自交系群体在温室和田间试验中进行了评估，以研究抗性的遗传基础。在 BoostND 群体中鉴定到染色体 3B、5A 和 5B 上的 QTL。在所有环境中均检测到 3B 和 5A QTL，但在温室条件下，3B QTL 最强，解释了 38%的表型变异，而 5A QTL 在田间条件下最为显著，解释了高达 29%的变异。在 ITMI 群体中，染色体 7D 上的一个 QTL 解释了温室中高达 46%的表型变异和田间条件下 18%的表型变异。两个群体中的 BLS 严重程度与抽穗天数呈负相关，并且这些性状的一些 QTL 重叠，这解释了较晚熟的品系具有相对较高水平的 BLS 抗性的趋势。与 QTL 相关的标记被转换为 KASP 标记，这将有助于将 QTL 部署到用于开发抗 BLS 小麦品种的优良品系中。
