【摘要】 分别对湖南、湖北、广东、福建等稻区中的近 2 0个地区稗草品系对二氯喹啉酸的抗性水平进行了系统鉴定 ,结果表明 :湖南省安乡县稗草已对二氯喹啉酸产生了极明显的抗性 ,以 5 0 %芽长抑制中浓度IC50 为标准 ,其相对抗性比值高达 2 8.74 ;湖南省常德市郊、汉寿县和湖北省黄梅县的稗草对二氯喹啉酸的抗药性也可能正在形成 ,其相对抗性比值在 2 .13～ 2 .78之间 ;而广东省、福建省等一些地区的稗草尚未对二氯喹啉酸表现出抗性 .用等浓度效果法和茎叶喷雾处理法也同样一致的得到了此结果更多还原

【Abstract】 The resistance of Echinochloa crusglli (barnyardgrass) to quinclorac was determined in 20 rice planted areas in south and middle China. The results showed that the quinclorac IC 50 value (dose causing 50% reduction in shoot length) for the resistance biotype in Anxiang county of Hunan province was 28.74 fold greater than the standards biotype. It was obvious that the biotype in Anxiang county was highly resistant to quinclorac. The resistance of barnyardgrass to quinclorac was being developed in those areas, such as Changde county and Hanshou county of Hunan province, Huangmei county of Hubei province, the quinclorac IC 50 value (dose causing 50% reduction in shoot length) for those were 2.13～2.78. However, all of the biotypes in Guangdong province were susceptible to quinclorac. The results of the resistance of barnyardgrass to quinclorac were also demonstrated by two other methods.更多还原