Fusarium head blight (FHB) is a devastating fungal disease of small-grain cereals that results in severe yield and quality losses. FHB resistance is controlled by resistance components including incidence, field severity, visual rating index, Fusarium damaged kernels (FDKs), and the accumulation of the mycotoxin deoxynivalenol (DON). Resistance conferred by each of these components is partial and must be combined to achieve resistance sufficient to protect wheat from yield losses. In this study, two biparental mapping populations were analyzed in Canadian FHB nurseries and quantitative trait loci (QTL) mapped for the traits listed above. Nine genomic loci, on 2AS, 2BS, 3BS, 4AS, 4AL, 4BS, 5AS, 5AL, and 5BL, were enriched for the majority of the QTL controlling FHB resistance. The previously validated FHB resistance QTL on 3BS and 5AS affected resistance to severity, FDK, and DON in these populations. The remaining seven genomic loci colocalize with flowering time and/or plant height QTL. The QTL on 4B was a major contributor to all field resistance traits and plant height in the field. QTL on 4AL showed contrasting effects for FHB resistance between Eastern and Western Canada, indicating a local adapted resistance to FHB. In addition, we also found that the 2AS QTL contributed a major effect for DON, and the 2BS for FDK, while the 5AL conferred mainly effect for both FDK/DON. Results presented here provide insight into the genetic architecture underlying these resistant components and insight into how FHB resistance in wheat is controlled by a complex network of interactions between genes controlling flowering time, plant height, local adaption, and FHB resistance components.

赤霉病 (FHB) 是小粒谷物的一种毁灭性真菌病，会导致严重的产量和质量损失。 FHB 抗性由抗性成分控制，包括发生率、田间严重程度、视觉评级指数、镰刀菌受损籽粒 (FDK) 和霉菌毒素脱氧雪腐镰刀菌烯醇 (DON) 的积累。这些成分所赋予的抗性都是部分的，必须结合起来才能获得足以保护小麦免受产量损失的抗性。在本研究中，对加拿大 FHB 苗圃的两个双亲作图群体进行了分析，并对上述性状进行了数量性状位点 (QTL) 作图。 2AS、2BS、3BS、4AS、4AL、4BS、5AS、5AL 和 5BL 上的 9 个基因组位点富集了大多数控制 FHB 抗性的 QTL。先前验证的 3BS 和 5AS 上的 FHB 抗性 QTL 影响这些人群对严重程度、FDK 和 DON 的抗性。其余七个基因组位点与开花时间和/或株高 QTL 共定位。 4B 上的 QTL 是田间所有田间抗性性状和株高的主要贡献者。 4AL 上的 QTL 在加拿大东部和西部之间显示出对 FHB 抗性的对比效应，表明对 FHB 的局部适应抗性。此外，我们还发现2AS QTL 对DON 起主要作用，2BS 对FDK 起主要作用，而5AL 对FDK/DON 均起主要作用。这里提出的结果提供了对这些抗性成分背后的遗传结构的深入了解，并深入了解了控制开花时间、株高、局部适应和 FHB 抗性成分的基因之间复杂的相互作用网络如何控制小麦的 FHB 抗性。