Abstract Fusarium graminearum is perhaps best known for causing head blight in wheat and ear and stalk rot in corn. However, F. graminearum can also cause seedling diseases and root rot on many field crops including wheat, corn, soybean, and dry bean. In 2019, a new Succinate Dehydrogenase Inhibitor (SDHI) fungicide, pydiflumetofen (Syngenta, Switzerland), was registered for management of Fusarium Head Blight of wheat and corn ear rot. Here, we determined the sensitivity of isolates of F. graminearum from wheat, corn, soybean and dry bean from Michigan to this new active ingredient. In vitro sensitivity of 94 isolates was assessed with a poison plate mycelial growth assay, and a subset with 21 isolates was also tested with a spore germination assay. The effective concentration that reduced growth or germination by 50% (EC50) was determined for each isolate. Mycelial growth EC50 values ranged from 0.008 to 0.263 μg/mL, with a mean of 0.060 μg/mL. EC50 values for spore germination assays ranged from 0.167 to 0.538 μg/mL, with a mean of 0.321 μg/mL. This study demonstrates both mycelial growth and spore germination are inhibited by this new chemistry in vitro. This data also establishes baseline sensitivity values of Michigan populations of F. graminearum before widespread application of this chemistry on commercial fields.

中文翻译：

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美国密歇根州小麦、玉米、干豆和大豆中禾谷镰刀菌对 Pydiflumetofen 的基线敏感性

摘要 Fusarium graminearum 可能以引起小麦赤霉病和玉米穗腐病而闻名。然而，禾谷镰刀菌也会导致包括小麦、玉米、大豆和干豆在内的许多大田作物的幼苗病害和根腐病。2019 年，一种新的琥珀酸脱氢酶抑制剂 (SDHI) 杀菌剂 pydiflumetofen（瑞士先正达）注册用于防治小麦枯萎病和玉米穗腐病。在这里，我们确定了来自密歇根州小麦、玉米、大豆和干豆的禾谷镰刀菌分离株对这种新活性成分的敏感性。94 个分离株的体外敏感性用毒板菌丝体生长试验评估，21 个分离株的子集也用孢子萌发试验进行了测试。对每个分离株确定了使生长或发芽减少 50% (EC50) 的有效浓度。菌丝生长 EC50 值范围为 0.008 至 0.263 μg/mL，平均值为 0.060 μg/mL。孢子萌发试验的 EC50 值范围为 0.167 至 0.538 μg/mL，平均值为 0.321 μg/mL。这项研究表明，这种新化学物质在体外抑制了菌丝体生长和孢子萌发。该数据还确定了密歇根州禾谷镰刀菌种群在该化学品在商业领域广泛应用之前的基线灵敏度值。这项研究表明，这种新化学物质在体外抑制了菌丝体生长和孢子萌发。该数据还确定了密歇根州禾谷镰刀菌种群在该化学品广泛应用于商业领域之前的基线灵敏度值。这项研究表明，这种新化学物质在体外抑制了菌丝体生长和孢子萌发。该数据还确定了密歇根州禾谷镰刀菌种群在该化学品广泛应用于商业领域之前的基线灵敏度值。