浙江稻区千金子对氰氟草酯和噁唑酰草胺的抗药性及其分子机制研究

千金子是中国直播稻田的优势禾本科杂草之一，严重威胁水稻的产量和品质。为了进一步明确浙江地区水稻田千金子对芳氧苯氧丙酸类除草剂的抗性发生情况，本研究从浙江部分稻区共采集了11个千金子种群 (其中1个为敏感种群)，通过整株植物测定法检测了各种群对氰氟草酯和噁唑酰草胺的敏感性。结果显示:共有8个种群对氰氟草酯产生了抗性 (抗性指数为2.1~79.1)，9个种群对噁唑酰草胺产生了抗性 (抗性指数为2.0~31.0)，其中对氰氟草酯的抗性问题更为显著。在此基础上，通过基因扩增和克隆，对敏感种群和抗性种群的乙酰辅酶A羧化酶 (Acetyl-CoA carboxylase，ACCase) 基因部分序列进行比对，结果在3个抗性种群中发现突变，其中1个种群为Ile-1781-Val突变，另外2个种群则为Trp-2027-Cys突变。该研究结果表明，目前浙江部分稻区千金子种群已对氰氟草酯和噁唑酰草胺产生了抗药性，其中靶标酶基因突变是导致部分种群产生抗药性的原因之一。

Resistance of Leptochloa chinensis (L.) Nees to cyhalofop-butyl and metamifop in rice fields of Zhejiang Province and involved molecular mechanism

Sprangletop (Leptochloa chinensis(L.) Nees) is one of the most serious grass weeds which can cause damage to rice field in China. To determine the resistance level of L. chinensis to aryloxyphenoxypropionates herbicides in rice fields in Zhejiang Province, a total of 11 L. chinensis populations (including one susceptible population) were collected in this study. Results of whole-plant dose-response assay tests showed that 8 populations had developed resistance to cyhalofop-butyl (resistance index: 2.1-79.1) and 9 populations had developed resistance to metamifop (resistance index: 2.0-31.0). Partial sequences of the ACCase gene in the susceptible and resistant populations were analyzed by PCR and gene clone. The Ile-1781-Val mutation was found in one resistant population and the Trp-2027-Cys mutation was found in two resistant populations. In conclusion, this study revealed that L. chinensis in rice fields in Zhejiang Province had developed different resistance levels to cyhalofop-butyl and metamifop, the Ile-1781-Val and Trp-2027-Cys mutations in the ACCase gene might contribute to the resistance in several populations.