【作者】 曲明静；

【导师】 韩召军；

【作者基本信息】 南京农业大学 ， 农业昆虫与害虫防治， 2005， 博士

【摘要】 二化螟Chilo suppressalis Walker是水稻的重要害虫之一，常年在长江流域发生较重。上世纪90年代以来，二化螟的发生危害再次呈加重趋势，部分地区暴发危害，对水稻的高产稳产造成很大的威胁，而二化螟抗药性增强是其危害加重的重要原因之一。 三唑磷是近年来防治二化螟的主要替代药剂。本文对高抗地区-浙江省苍南县的二化螟进行了连续三年的监测(2002～2004)，并通过筛选抗性品系，对其抗药性机理、抗药性现实遗传力、抗三唑磷二化螟品系的适合度、抗性稳定性和交互抗性进行了研究，试图为抗性治理提供科学依据。现将研究结果总结如下： 1 二化螟田间抗药性监测 对浙江省苍南县稻田一代二化螟的抗药性进行了连续三年(2002～2004年)的监测，结果表明：2002年苍南田间种群已经对多种杀虫剂产生抗性，对三唑磷、氟虫腈、水胺硫磷、甲胺磷的抗性倍数分别为：203.3、19.0、3.7、26.6倍。三年后田间二化螟对三唑磷和阿维菌素的抗药性上升迅速，抗性倍数达2367.3和30.0倍；对水胺硫磷和甲胺磷的抗性略有上升，而对氟虫腈的抗性有所下降。至2004年，这3种药剂的抗性倍数分别为8.8、34.8和7.4倍。该研究结果揭示了二化螟抗药性变化与田间用药量和用药种类变化的密切关系。 2 二化螟对三唑磷的室内抗性选育 在室内用三唑磷对采自浙江省苍南县的二化螟进行连续14代筛选，抗性由203.3倍上升到3272.6倍；其中在筛选的前12代抗性上升较慢，在后几代抗性上升很快。利用14代的选育结果，计算得到室内三唑磷筛选抗性的现实遗传力h~2为0.3105，说明二化螟对三唑磷的抗性风险较大。敏感性回复实验表明，高抗二化螟(RR 1523.7)在停止筛选后，经过5代抗性水平下降到327.1倍，随后保持相对稳定，当再次恢复筛选时，抗性水平又迅速上升。结论认为，二化螟对三唑磷极易产生高水平抗性，且一旦产生高抗后，停止用药虽然可以使其敏感性明显下降，但不可能回复原来的敏感性水平。因此，二化螟对三唑磷的抗性应采取早期治理，避免产生高水平抗性，一旦产生高水平抗性后，便不宜再用于二化螟的田间防治。 3 二化螟抗三唑磷品系的交互抗性更多还原

【Abstract】 Rice stem borer, Chilo suppressalis Walker, one of the most important rice pests in China, always damages rice production heavily in the Yangzi River. Since the 90s of last century, it breaks out continuously and become even difficult to be controlled because of its high resistance to different insecticides, which menace the stability of rice production seriously.Triazophos is one of the major pesticides used to control rice stem borer in the field. In order to make good use of this insecticide and practice efficient resistance management, the resistance of the field rice stem borer collected from high resistant area was surveyed. Furthermore, the resistant strain was selected, and the resistance reality heredity(h~2), fitness cost, stability, cross-resistance and resistance mechanism were all tested, and the gene for target enzyme, acetylcholinesterase (AChE) was also cloned for searching its insensitive mutations. The results were summarized as follows:1 Resistance monitoring with field rice stem borerThe rice stem borer collected from Cangnan County, Zhejiang Province was tested for its resistance to some conventional pesticides from 2002 to 2004. The results indicated that in 2002 the field population of rice stem borer had developed resistance to several kinds of pesticides. The resistance ratio for triazophos, fipronil, isocarbophos and methamidophos was 203.3, 18.9, 3.7 and 26.6 fold, respectively. Three years later, its resistance to triazophos and abamectin increased and reached to 2367.3 and 30. But at the same time, its resistance to isocarbophos increased only slightly to 8.4, while to fipronil decreased to 7.4. Further analysis revealed that the resistance of rice stem borer varied with the quantity and the kinds of insecticides used in the field.更多还原