湖南稻区稗草对二氯喹啉酸的抗药性研究

Studies on the resistance of Echinochloa crusgalli to quinclorac in rice planting areas in Hunan Province

对湖南部分稻区稗草生物型对二氯喹啉酸的抗性水平进行监测。琼脂法测定结果表明,湖南安乡稗草生物型已对二氯喹啉酸产生了明显的抗性,2001年安乡稗草生物型IC50结果显示,其最高相对抗性倍数高达63.80;常德市郊、汉寿县、长沙县高桥镇和春华镇的稗草生物型对二氯喹啉酸的抗药性正在形成,IC50相对抗性倍数比值为2.15-2.78;而其他地区稗草生物型尚未对二氯喹啉酸产生抗性。茎叶喷雾法测定表明,在室内即便是使用高浓度400 mg／L二氯喹啉酸也不能很好地控制安乡稗草生物型;田间使用浓度为6倍于田间推荐用量(1 350 g／hm2)的二氯喹啉酸不能有效防治安乡稗草生物型,而用田间推荐量(225 g／hm2)的二氯喹啉酸可有效的防治敏感性稗草生物型。以上结果表明湖南安乡稗草生物型已对二氯喹啉酸产生极明显的抗药性。

The resistance of Echinohloa crusgalli (barnyardgrass) to quinclorac was deter mined in rice-planting areas in Hunan Province in this study. The biotype in Anxiang County was highly resistant to quinclorac, and the IC50 value for Anxiang biotype (2001) was 63.8 using agar method. The resistance of barnyardgrass to quinclorac was developed in those areas, such as Changde County,Hanshou County and Gaoqiao Town and Chunhua Town in Changsha County, and the IC50 values of quinclorac ranged from 2.15 to 2.78, where as the other biotypes in Hunan Province were susceptible to quinclorac. The Anxiang biotype could not be controlled by 400 mg/L quinclorac in the lab by stem spraying method. The Anxiang biotype could not be controlled by 1 350 g/ hm2 quinclorac in the field either, while the susceptible biotype could be controlled by 225 g/ hm2 quinclorac in the field. The results always showed that the Anxiang biotype was highly resistant to quinclorac using three methods.