抗杀螟硫磷二化螟的抗性遗传力研究

ESTIMATION OF REALIZED HERITABILITY OF RESISTANCE TO FENITROTHION IN THE RICE STEM BORER CHILO SUPPRESSALIS

应用数量遗传学的方法分析了水稻二化螟（Ｃｈｉｌｏｓｕｐｐｒｅｓｓａｌｉｓ）对杀螟硫磷抗药性的遗传力，并就遗传力和杀虫剂的杀死率对抗性发展速率的影响进行了预测。研究结果表明：二化螟对杀螟硫磷抗性的遗传力较低（ｈ２＝０．２７７〕，产生高抗性的潜力不大。即使在室内选择的条件下，要获得１０倍的抗性约需要６—１２代；在野外条件下则需要更长的时间（１５－３２代）。因此，结合抗性变化动态的监测结果，我们认为在野外条件下二化螟是不致于产生高抗性，杀螟硫磷仍不失为二化螟抗性治理系统中有效品种之一。

With the method of probit analysis, we estimated the realized heritability (h2) of resistance to fenitrothion in the rice stem borer (Chilo suppressalis Walker). The results demonstrated that tolerant phenotypes in the observed population are lowly heritable (h2= 0.277) and that the population has no potential for higher increase in tolerance to fenitrothion. Under the circumstances of laboratory selection, the population has to propagate about 6-12 generations to acquire 10-fold resistance to fenitrothion, and it takes a longer time (16-35 generations) for the field population to do so. Our results suggest that the risk to developing high resistance to fenitrothion is small and thus, fenitrothion should be considered as an effective chemical agent in the system of insecticide resistance management for therice stem borer.