Department of Plant Pathology, University of Kentucky, Princeton, KY 42445, U.S.A.
Department of Crop Sciences, University of Illinois, Urbana, IL 61801, U.S.A.
Plant Dis. 2022 Oct;106(10):2631-2637. doi: 10.1094/PDIS-08-21-1836-RE. Epub 2022 Sep 9.
Brown spot, caused by , is a common foliar disease of soybean (). Applications of fungicide products that contain quinone outside inhibitor (QoI) active ingredients to soybean fields have contributed to the selection and development of QoI-resistant populations of . We investigated the molecular mechanisms of QoI-resistance in these populations through targeted analysis of the cytochrome gene. Isolates of collected from several soybean fields over different seasons varied in sensitivity to QoI fungicides. Characterization of the cytochrome gene revealed a mutation that changed an amino acid from glycine to alanine at codon 143 - one that is generally associated with QoI fungicide resistances. A PCR assay was developed that allowed successful discrimination of QoI-sensitive and -resistant isolates based on the G143A mutation. Results of this study demonstrated that 47.5% of isolates tested were resistant to QoI fungicides. Accurate monitoring of this mutation will help slow the spread of QoI resistance and will be important for fungicide resistant management in this pathosystem.
褐斑病由 引起，是大豆（）叶片的常见病害。将含有醌外抑制剂（QoI）活性成分的杀菌剂产品应用于大豆田，导致了对 QoI 的抗性种群的选择和发展。我们通过对细胞色素基因的靶向分析，研究了这些种群中 QoI 抗性的分子机制。从不同季节的几个大豆田中收集的 分离物对 QoI 杀菌剂的敏感性存在差异。细胞色素基因的特征表明，密码子 143 处的一个氨基酸从甘氨酸变为丙氨酸的突变-通常与 QoI 杀菌剂抗性有关。开发了一种 PCR 检测方法，可以根据 G143A 突变成功区分 QoI 敏感和抗性分离物。这项研究的结果表明，测试的 分离物中有 47.5%对 QoI 杀菌剂有抗性。对该突变的准确监测将有助于减缓 QoI 抗性的传播，并对该病理系统中的杀菌剂抗性管理非常重要。
