School of Molecular and Life Sciences, Curtin University, Bentley, Australia.
Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK.
Pest Manag Sci. 2020 Apr;76(4):1265-1272. doi: 10.1002/ps.5636. Epub 2019 Nov 21.
Powdery mildew caused by Blumeria graminis f. sp. hordei (Bgh) is a constant threat to barley production but is generally well controlled through combinations of host genetics and fungicides. An epidemic of barley powdery mildew was observed from 2007 to 2013 in the West Australian grain belt.
We collected isolates across Australia, examined their sensitivity to demethylation inhibitor (DMI) fungicides and sequenced the Cyp51B target gene. Five amino acid substitutions were found, of which four were novel. The most resistant haplotypes increased in prevalence from 0% in 2009 to 16% in 2010 and 90% in 2011. Yeast strains expressing the Bgh Cyp51 haplotypes replicated the altered sensitivity to various DMIs and these results were complemented by in silico protein docking studies.
The planting of very susceptible cultivars and the use of a single fungicide mode of action was followed by the emergence of a major epidemic of barley powdery mildew. Widespread use of DMI fungicides led to the selection of Bgh isolates carrying both the Y137F and S524T mutations, which, as in Zymoseptoria tritici, account for resistance factors varying from 3.4 for propiconazole to 18 for tebuconazole, the major azoles used at that time in WA. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
禾本科布氏白粉菌（Bgh）引起的白粉病一直是大麦生产的威胁，但通过宿主遗传和杀菌剂的组合通常可以很好地控制。2007 年至 2013 年，在西澳大利亚粮食带观察到大麦白粉病流行。
我们在澳大利亚各地收集了分离株，检测了它们对脱甲基抑制剂（DMI）杀菌剂的敏感性，并对 Cyp51B 靶基因进行了测序。发现了五个氨基酸取代，其中四个是新的。最具抗性的单倍型的流行率从 2009 年的 0%增加到 2010 年的 16%和 2011 年的 90%。表达 Bgh Cyp51 单倍型的酵母菌株复制了对各种 DMI 的敏感性变化，这些结果通过计算机蛋白对接研究得到了补充。
非常易感品种的种植和单一杀菌剂作用模式的使用，随后出现了大麦白粉病的大流行。DMI 杀菌剂的广泛使用导致了携带 Y137F 和 S524T 突变的 Bgh 分离株的选择，与叶斑病类似，这些突变导致了从丙环唑的 3.4 倍到当时在西澳主要使用的唑菌酯的 18 倍的抗性因子的变化。2019 年，作者。害虫管理科学由 John Wiley & Sons Ltd 代表化学工业协会出版。
