湖南稻区稗草对二氯喹啉酸的抗性研究

利用整株测定法,测定湖南省主要稻区29个稗草生物型对二氯喹啉酸的抗性。结果表明,湖南省隆回县的生物型稗草对二氯喹啉酸最敏感,其EC50为76.388 3 g a.i./hm2,为敏感生物型。湖南省益阳芷湖口镇和湖南省长沙望城县(直播田)的生物型稗草对二氯喹啉酸的EC50分别为1 567.164 g a.i./hm2和2 477.542 g a.i./hm2,抗药性指数分别达20.52和32.43,表明这两种生物型稗草的抗药性处于高水平抗性。其中10个生物型稗草的EC50为155.931 8～375.114 g a.i./hm2,抗药性指数为2.02～4.91,表明这些生物型稗草已产生抗性。而其余16个生物型稗草的EC50为84.020 3～151.596 g a.i./hm2,抗药性指数为1.10～1.98,表明这些地方稗草的敏感性正在下降。

Studies on Resistance of Echinochloa crusglli to Quinclorac in the Rice Plantation Area in Hunan Province

The greenhouse study was carried out to determine the resistance level to quinclorac of 29 barnyard grass biotypes collected from rice planting area in Hunan province.The result showed that the biotype collected from Shaoyang suburb was the most susceptible barnyard grass to quinclorac,the EC50 was 76.3883 g a.i./hm2.The biotype collected from Shaoyang suburb as the susceptible biotype,the biotypes collected from Zhihukou town in Yiyang and Wangcheng in Changsha presented very high resistance to quinclorac,the EC50 was 1567.164 g a.i./hm2 and 2477.542 g a.i./hm2 respectively,and its resistance index was riched to 20.52 and 32.43 respectively which indicated the two biotypes had resistance to quinclorac on high level.Among 29 biotypes 10 were resistant to quinclorac with a EC50 value ranged from 155.9318 to 375.114 g a.i./hm2,and a resistant index ranged from 2.02 to 4.91.And the susceptibility to quinclorac of the other 16 biotypes was decreasing with the EC50 value ranged from 84.0203 to 151.596 g a.i./hm2,and the resistant index ranged from 1.10 to 1.98.