Department of Agricultural Chemistry and Edaphology, University of Cordoba, 14071 Cordoba, Spain.
J Agric Food Chem. 2009 May 27;57(10):4273-8. doi: 10.1021/jf803386v. Epub 2009 Apr 22.
Two biotypes of Scirpus mucronatus not controlled with the herbicide bensulfuron-methyl in rice fields were characterized by using field, greenhouse, and laboratory techniques. Seeds were collected in two rice areas [Parral (R1) and Linares (R2)], where bensulfuron-methyl at 150 g ha(-1) did not control S. mucronatus. A third seed sample of S. mucronatus susceptible (S) to bensulfuron-methyl was collected in an area from Chile. The dose-response studies confirmed resistance to bensulfuron-methyl in R1 and R2 S. mucronatus biotypes; ratios (R/S) of the ED(50) values of resistant to susceptible plants were 1719 and 1627 for R1 and R2, respectively. The biotype R1 also showed strong cross-resistance (ratios ranging from 1719 to 43) to sulfonylureas (bensulfuron-methyl, cyclosulfamuron, ethoxysulfuron, imazosulfuron, and pyrazosulfuron-ethyl) and imidazolinone (imazamox) and a weak cross-resistance (ratio of 1.705) to pyrimidinyloxybenzoates (bispyribac-sodium), all ALS inhibiting herbicides used in rice. Absorption, translocation, and metabolism results did not explain the differences in susceptibility among biotypes. The in vitro assays confirmed cross-resistance to all ALS inhibitors tested and the level of cross resistance was bensulfuron-methyl > imazosulfuron ≫ cyclosulfamuron ≫ pyrazosulfuron-ethyl ≫ ethoxysulfuron > imazamox ≫ bispiribac-sodium. Molecular studies demonstrated that the Pro197His amino acid substitution on the ALS enzyme could explain the loss of affinity for the ALS-inhibiting herbicides.
两种未被稻田除草剂苯磺隆甲酯控制的荸荠生物型，采用田间、温室和实验室技术进行了特征描述。种子分别采集于两个水稻种植区[Parral（R1）和 Linares（R2）]，在这两个地区，苯磺隆甲酯施用量为 150 g/ha 时，不能有效控制荸荠的生长。第三个对苯磺隆甲酯敏感的（S）荸荠种子样本采集于智利的一个地区。剂量反应研究证实，R1 和 R2 的荸荠生物型对苯磺隆甲酯具有抗药性；抗性植物与敏感植物的 ED50 值之比（R/S）分别为 1719 和 1627。生物型 R1 还对磺酰脲类（苯磺隆甲酯、环丙磺酰胺、乙氧嘧磺隆、唑嘧磺隆和吡嘧磺隆-乙基）和咪唑啉酮类（咪草烟）表现出较强的交叉抗性（比值范围为 1719 至 43），以及对嘧啶氧苯甲酸酯类（双吡氟草腙钠盐）表现出较弱的交叉抗性（比值为 1.705），这些都是水稻田中使用的 ALS 抑制剂类除草剂。吸收、转运和代谢结果并不能解释生物型之间敏感性的差异。体外测定证实了对所有测试的 ALS 抑制剂的交叉抗性，且交叉抗性水平为：苯磺隆甲酯＞唑嘧磺隆＞环丙磺酰胺＞吡嘧磺隆-乙基＞乙氧嘧磺隆＞咪草烟＞双吡氟草腙钠盐。分子研究表明，ALS 酶上 Pro197His 氨基酸取代可以解释其对 ALS 抑制剂类除草剂亲和力的丧失。
