Aristotle University of Thessaloniki, School of Agriculture, Thessaloniki, Greece.
Institute of Applied Biosciences-CERTH, 6th Km. Charilaou-Thermi Road, Thessaloniki, Greece.
Pestic Biochem Physiol. 2020 Mar;164:65-72. doi: 10.1016/j.pestbp.2019.12.010. Epub 2019 Dec 28.
Three putative resistant (R1, R2, R3) and one susceptible (S) Lolium rigidum populations originating from Greece were studied for resistance to ALS and ACCase inhibiting herbicides, using whole plant, sequencing of als and accase gene, and in vitro ALS activity assays. The S and two R (R1, R2) populations were also evaluated for fitness in competition with wheat. The whole plant assay indicated unsatisfactory control of the R populations with mesosulfuron-methyl + iodosulfuron-methyl or pinoxaden application, whereas sequencing of the als gene revealed that all ALS-resistant individuals had a Pro-197 substitution by Leu, Glu, Ser, Ala, Thr, or Gln. In addition, the accase gene of all pinoxaden resistant individuals had an Ile-2041 substitution by Asn or Thr. Furthermore, sequencing of the individuals surviving mesosulfuron-methyl + iodosulfuron-methyl or pinoxaden treatment revealed co-existence of point mutations in the accase or als genes, respectively, demonstrating multiple resistance. The in vitro activity of the ALS enzyme confirmed that resistance to mesosulfuron-methyl + iodosulfuron-methyl was due altered target-site. The recorded higher vigor and greater competitive ability of S population against wheat as compared with that of the R populations suggests an associated fitness cost with multiple resistance.
研究了来自希腊的三个假定抗性（R1、R2、R3）和一个敏感（S）Lolium rigidum 种群对 ALS 和 ACCase 抑制性除草剂的抗性，使用全植物、als 和 accase 基因测序和体外 ALS 活性测定。还评估了 S 和两个 R（R1、R2）种群与小麦竞争的适应性。全植物测定表明，用 mesosulfuron-methyl + iodosulfuron-methyl 或 pinoxaden 处理 R 种群的控制效果不理想，而 als 基因测序表明，所有 ALS 抗性个体的 Pro-197 被 Leu、Glu、Ser、Ala、Thr 或 Gln 取代。此外，所有对 pinoxaden 有抗性的个体的 accase 基因都有 Ile-2041 被 Asn 或 Thr 取代。此外，对经 mesosulfuron-methyl + iodosulfuron-methyl 或 pinoxaden 处理后存活的个体进行测序，发现 accase 或 als 基因分别存在点突变的共存，表明存在多重抗性。ALS 酶的体外活性证实，对 mesosulfuron-methyl + iodosulfuron-methyl 的抗性是由于靶标位点的改变。与 R 种群相比，S 种群对小麦的活力更高、竞争力更强，这表明与多重抗性相关的适应性成本。
