Department of Plant Agriculture, University of Guelph, Guelph, ON, N1G 2W1, Canada.
Département de Phytologie, Université Laval, Québec City, Québec, G1V 0A6, Canada.
BMC Plant Biol. 2023 May 31;23(1):290. doi: 10.1186/s12870-023-04306-8.
Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most destructive wheat diseases worldwide. FHB infection can dramatically reduce grain yield and quality due to mycotoxins contamination. Wheat resistance to FHB is quantitatively inherited and many low-effect quantitative trait loci (QTL) have been mapped in the wheat genome. Synthetic hexaploid wheat (SHW) represents a novel source of FHB resistance derived from Aegilops tauschii and Triticum turgidum that can be transferred into common wheat (T. aestivum). In this study, a panel of 194 spring Synthetic Hexaploid Derived Wheat (SHDW) lines from the International Maize and Wheat Improvement Center (CIMMYT) was evaluated for FHB response under field conditions over three years (2017-2019). A significant phenotypic variation was found for disease incidence, severity, index, number of Fusarium Damaged Kernels (FDKs), and deoxynivalenol (DON) content. Further, 11 accessions displayed < 10 ppm DON in 2017 and 2019. Genotyping of the SHDW panel using a 90 K Single Nucleotide Polymorphism (SNP) chip array revealed 31 K polymorphic SNPs with a minor allele frequency (MAF) > 5%, which were used for a Genome-Wide Association Study (GWAS) of FHB resistance. A total of 52 significant marker-trait associations for FHB resistance were identified. These included 5 for DON content, 13 for the percentage of FDKs, 11 for the FHB index, 3 for disease incidence, and 20 for disease severity. A survey of genes associated with the markers identified 395 candidate genes that may be involved in FHB resistance. Collectively, our results strongly support the view that utilization of synthetic hexaploid wheat in wheat breeding would enhance diversity and introduce new sources of resistance against FHB into the common wheat gene pool. Further, validated SNP markers associated with FHB resistance may facilitate the screening of wheat populations for FHB resistance.
镰刀菌穗腐病（FHB）是由禾谷镰刀菌引起的，是全球最具破坏性的小麦病害之一。FHB 感染会导致真菌毒素污染，从而显著降低谷物产量和质量。小麦对 FHB 的抗性是数量遗传的，许多低效应数量性状位点（QTL）已在小麦基因组中定位。合成六倍体小麦（SHW）代表了一种源自节节麦和粗山羊草的新型 FHB 抗性来源，可被导入普通小麦（T. aestivum）。在这项研究中，来自国际玉米和小麦改良中心（CIMMYT）的 194 个春性合成六倍体衍生小麦（SHDW）品系在三年（2017-2019 年）的田间条件下对 FHB 反应进行了评估。发现疾病发生率、严重程度、指数、镰刀菌损伤籽粒（FDK）数量和脱氧雪腐镰刀菌烯醇（DON）含量存在显著表型变异。此外，在 2017 年和 2019 年，有 11 个品系的 DON 含量<10ppm。利用 90K 单核苷酸多态性（SNP）芯片阵列对 SHDW 品系进行基因分型，发现了 31K 个多态性 SNP，其次要等位基因频率（MAF）>5%，用于 FHB 抗性的全基因组关联研究（GWAS）。共鉴定出 52 个与 FHB 抗性相关的显著标记-性状关联，其中 5 个与 DON 含量相关，13 个与 FDK 百分比相关，11 个与 FHB 指数相关，3 个与发病率相关，20 个与严重程度相关。对与标记相关的基因进行调查，确定了 395 个可能参与 FHB 抗性的候选基因。总的来说，我们的研究结果强烈支持这样一种观点，即利用合成六倍体小麦进行小麦育种将增强多样性，并将新的 FHB 抗性来源引入普通小麦基因库。此外，与 FHB 抗性相关的经验证的 SNP 标记可能有助于筛选抗 FHB 的小麦群体。
