Genetic assays to identify herbicide-resistant plants are a promising tool to reduce herbicide failures. However, the genetic basis of herbicide resistance is frequently unknown. In clonal weed species, DNA fingerprinting could be a useful tool to identify known resistant versus susceptible genets (clones) that occur in multiple locations, without an immediate need for understanding the genetic mutation(s) conferring resistance. Eurasian watermilfoil (Myriophyllum spicatum L.) and hybrids with native northern watermilfoil (Myriophyllum spicatum × Myriophyllum sibiricum Kom.) are mostly clonal invasive aquatic plants, and the same clones can be found in multiple waterbodies. Previously, a clone was confirmed as resistant to the commonly used herbicide fluridone, and a recent genetic survey in Michigan identified this genotype (MG-237) in at least seven other lakes. We hypothesized that MG-237 collected from different lakes would also exhibit fluridone resistance. However, MG-237 may have accumulated resistance mutations at different times during its spread across Michigan, resulting in fluridone-resistant and fluridone-susceptible MG-237 clones distributed in different lakes. We used a herbicide assay to test the response of several accessions, including MG-237 accessions from multiple lakes, to the Michigan operational rate of 6 µg L−1 fluridone. We found that all accessions of MG-237 exhibited resistance to 6 µg L−1 fluridone. A second genotype (MG-377) was also resistant to 6 µg L−1 fluridone. The rest of the accessions were found to be significantly injured by 6 µg L−1 fluridone. Our results suggest that 6 µg L−1 fluridone would not effectively control waterbodies dominated by MG-237 or MG-377, whereas waterbodies dominated by the other genotypes in our study would likely be controlled. Although more studies are needed to identify the variation in sensitivity of the accessions tested here and the genetic basis of fluridone resistance in Myriophyllum, our results suggest that multilocus genotype data may be an effective tool to identify and track herbicide-resistant genotypes of Myriophyllum in the short term.

中文翻译：

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欧亚 (Myriophyllum spicatum) 和杂种 (Myriophyllum spicatum × Myriophyllum sibiricum) 水菖蒲对氟利酮操作率的抗性克隆的鉴定

鉴定抗除草剂植物的遗传测定是减少除草剂失效的有前途的工具。然而，除草剂抗性的遗传基础通常是未知的。在克隆杂草物种中，DNA 指纹识别可能是一种有用的工具，可用于识别发生在多个位置的已知抗性和易感基因（克隆），而无需立即了解赋予抗性的基因突变。欧亚水草（穗状花序L.) 和与本地北方水草的杂交种 (穗状花序×西伯利亚桃金娘Kom.) 主要是克隆入侵水生植物，在多个水体中可以找到相同的克隆。此前，一个克隆被证实对常用的除草剂氟啶酮具有抗性，最近在密歇根州进行的一项基因调查在至少七个其他湖泊中发现了这种基因型 (MG-237)。我们假设从不同湖泊收集的 MG-237 也会表现出氟啶酮抗性。然而，MG-237 可能在其在密歇根州传播期间的不同时间积累了抗性突变，导致氟啶酮耐药和氟啶酮敏感的 MG-237 克隆分布在不同的湖泊中。我们使用除草剂测定来测试几种种质（包括来自多个湖泊的 MG-237 种质）对密歇根州 6 µg L 操作率的响应-1氟啶酮。我们发现 MG-237 的所有种质都表现出对 6 µg L-1氟啶酮。第二种基因型 (MG-377) 也对 6 µg L 具有抗性-1氟啶酮。发现其余的种质受到 6 µg L 的显着伤害-1氟啶酮。我们的结果表明 6 µg L-1氟啶酮不能有效控制以 MG-237 或 MG-377 为主的水体，而在我们的研究中，以其他基因型为主的水体可能会受到控制。虽然需要更多的研究来确定这里测试的种质的敏感性变化以及氟虫酮抗性的遗传基础桃金娘，我们的结果表明，多位点基因型数据可能是识别和追踪抗除草剂基因型的有效工具。桃金娘在短期内。