Powdery mildew is an important foliar disease of barley (Hordeum vulgare L.) caused by the biotrophic fungus Blumeria graminis f. sp. hordei (Bgh). The understanding of the resistance mechanism is essential for future resistance breeding. In particular, the identification of race-nonspecific resistance genes is important because of their regarded durability and broad-spectrum activity. We assessed the severity of powdery mildew infection on detached seedling leaves of 267 barley accessions using two poly-virulent isolates and performed a genome-wide association study exploiting 201 of these accessions. Two-hundred and fourteen markers, located on six barley chromosomes are associated with potential race-nonspecific Bgh resistance or susceptibility. Initial steps for the functional validation of four promising candidates were performed based on phenotype and transcription data. Specific candidate alleles were analyzed via transient gene silencing as well as transient overexpression. Microarray data of the four selected candidates indicate differential regulation of the transcription in response to Bgh infection. Based on our results, all four candidate genes seem to be involved in the responses to powdery mildew attack. In particular, the transient overexpression of specific alleles of two candidate genes, a potential arabinogalactan protein and the barley homolog of Arabidopsis thaliana’s Light-Response Bric-a-Brac/-Tramtrack/-Broad Complex/-POxvirus and Zinc finger (AtLRB1) or AtLRB2, were top candidates of novel powdery mildew susceptibility genes.

白粉病是由大营养性真菌Blumeria graminis f引起的大麦（大麦（Hordeum vulgare L.））的一种重要叶面疾病。sp。大麦（BGH）。对抗性机制的理解对于将来的抗性育种至关重要。特别是非种族非特异性抗性基因的鉴定非常重要，因为它们具有持久性和广谱活性。我们使用两种多毒力分离株评估了267个大麦种的分离苗叶上白粉病的严重程度，并利用这些种中的201种进行了全基因组关联研究。位于六个大麦染色体上的214个标记与潜在的种族非特异性Bgh相关抵抗力或敏感性。基于表型和转录数据进行了四个有希望的候选者的功能验证的初始步骤。通过瞬时基因沉默以及瞬时过表达来分析特定的候选等位基因。四个选定候选物的微阵列数据表明，响应于Bgh感染，转录的差异调节。根据我们的结果，所有四个候选基因似乎都参与了对白粉病侵袭的反应。特别是，两个候选基因，潜在的阿拉伯半乳聚糖蛋白和拟南芥的光响应性Bric-a-Brac / -Tramtrack / -Broad Complex / -POxvirus和锌指（AtLRB1）或AtLRB2是新型白粉病敏感性基因的最佳候选对象。