Zymoseptoria tritici is the causative fungal pathogen of septoria tritici blotch (STB) disease of wheat (Triticum aestivum L.) that continuously threatens wheat crops in Ireland and throughout Europe. Under favorable conditions, STB can cause up to 50% yield losses if left untreated. STB is commonly controlled with fungicides; however, a combination of Z. tritici populations developing fungicide resistance and increased restrictions on fungicide use in the EU has led to farmers relying on fewer active substances. Consequently, this serves to drive the emergence of Z. tritici resistance against the remaining chemistries. In response, the use of resistant wheat varieties provides a more sustainable disease management strategy. However, the number of varieties offering an adequate level of resistance against STB is limited. Therefore, new sources of resistance or improved stacking of existing resistance loci are needed to develop varieties with superior agronomic performance. Here, we identified quantitative trait loci (QTL) for STB resistance in the eight-founder “NIAB Elite MAGIC” winter wheat population. The population was screened for STB response in the field under natural infection for three seasons from 2016 to 2018. Twenty-five QTL associated with STB resistance were identified in total. QTL either co-located with previously reported QTL or represent new loci underpinning STB resistance. The genomic regions identified and the linked genetic markers serve as useful resources for STB resistance breeding, supporting rapid selection of favorable alleles for the breeding of new wheat cultivars with improved STB resistance.

中文翻译：

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使用多亲小麦种群的遗传分析确定了小麦斑点病抗性的新来源

Zymoseptoria tritici 是小麦 (Triticum aestivum L.) 小麦斑点病 (STB) 的致病真菌病原体，该病不断威胁着爱尔兰和整个欧洲的小麦作物。在有利条件下，如果不加以处理，STB 可导致高达 50% 的产量损失。STB 通常用杀菌剂控制；然而，小麦单孢菌种群对杀菌剂产生抗药性以及欧盟对杀菌剂使用的限制增加导致农民依赖较少的活性物质。因此，这有助于推动小麦单孢菌对其余化学物质的抗性的出现。作为回应，使用抗性小麦品种提供了更可持续的疾病管理策略。然而，对 STB 具有足够抗性的品种数量有限。所以，需要新的抗性来源或改进现有抗性位点的叠加以开发具有优异农艺性能的品种。在这里，我们确定了八位创始人“NIAB Elite MAGIC”冬小麦群体中 STB 抗性的数量性状基因座（QTL）。从 2016 年到 2018 年，在自然感染下的三个季节对人群进行了田间 STB 反应的筛选。总共确定了 25 个与 STB 抗性相关的 QTL。QTL 要么与先前报道的 QTL 位于同一位置，要么代表支持 STB 抗性的新位点。鉴定的基因组区域和连锁遗传标记可作为STB抗性育种的有用资源，支持快速选择有利等位基因，用于培育具有改良STB抗性的小麦新品种。