中文摘要：

在延边部分稻田中发现对磺酰脲类除草剂农得时、草克星产生抗性的雨久花（Monochoria korsakowii Regel et Maack．）、慈姑（Sagittaria sagittrifolia L．）、扁秆蔗草（Scirpus planiculmis Fr．Schmidt）变异的生态型以及抗二氯喹啉酸的稗草（Echinochloa crusgallli L．）的变异生态型．与感性相比，抗性雨久花对磺酰脲类除草剂农得时的抗性系数（R50／S50）值为10．3，对草克星的抗性系数（R50／S50）值为6．5；抗性慈姑对农得时的抗性系数（R50／S50）值为16．04，对草克星的抗性系数（R50／S50）值为11．21．雨久花、慈姑对农得时和草克星产生交叉抗性．采用2倍标准剂量的农得时对茎叶进行处理，可以简便、快速、有效地鉴定上述杂草的抗、感性生态型．

英文摘要：

The sulfonylurea（SU） resistance biotypes Monochoria korsakowii Regel et Maack, Sagittaria sagittri folia L. , Scirpus planiculmis Fr. Schmidt and quinclorac resistance biotypes Echinochloa crusgallli L. were found in some paddy fields in Yanbian region. The resistant coefficient（R50/S50）of resistance biotype Monochoria korsakowii Regel et Maack. to bensulfuron was 10.3,but to pyruzasulfuron was 6.5. The resistant coefficient of resistance biotype Sagittaria sagittrifolia L. to bensulfuron was 16.04,but to pyruzasulfuron was 11.21. Monochoria korsakowii Regel et Maack. and Sagittaria sagittrifolia L. had crossed resistance to bensul- furon and pyruzasulfuron. The treatment of bensulfuron and quinclorac on stems and leaves using the double doses could indentify the resistant and suspective biotypes of the weeds above convieniently,fast and effectively.