抗虫转基因水稻和化学杀虫剂对稻田节肢动物群落的影响

从功能团优势度、功能团内科组成及其优势度、功能团个体数量、群落主要参数及群落结构相异性等方面，就含crylAb／crylAc融合基因的Bt水稻和化学杀虫剂对稻田节肢动物群落影响进行比较研究．结果表明，与对照田相比，Bt稻田的节肢动物功能团组成及其优势度、各功能团内科组成及其优势度分布、功能团内个体数量的时间动态、群落参数(物种丰富度、Shannon-Wiener多样性指数、均匀性指数、优势集中性指数)及时间动态在大多情况下均无显著差异，两者间群落结构相似性较高．Bt水稻对稻田节肢动物群落基本无明显的负效应、而化防田的功能团优势度等群落特征指标与对照田相比，有时具有明显甚至显著的差异；群落结构相似性也较低．综合分析表明，Bt水稻对稻田节肢动物群落的影响明显弱于化学杀虫剂。

Effects of Bacillus thuringiensis transgenic rice and chemical insecticides on arthropod communities in paddy-fields

This paper assessed the effects of cry1Ab/cry1Ac-carrying transgenic Bacillus thuringiensis rice (Bt rice) and chemical insecticides on the arthropod communities under paddy-field conditions in terms of arthropod guild dominance,family composition and dominance distribution of each guild,individuals of each guild,some common indices of arthropod communities,and community dissimilarity.In most cases,no significant differences were found between the Bt and control rice plots without any chemical insecticide spray in such arthropod community specific parameters as guild dominance,family composition and dominance distribution,temporal dynamics of the individuals of each guild or all arthropod,as well as some common community indices (including species richness,Shannon-Wiener diversity index,evenness index and dominant index) and their temporal dynamics.The similarity of arthropod community between the Bt and control rice plots were apparently higher.It was clear that Bt rice generally showed no marked negative effect on the arthropod community in paddy field.In contrast,some arthropod community specific parameters such as guild dominances in the control plot with chemical insecticide spray were in some cases markedly and even significantly different from those in the control plot without any chemical insecticide spray.The similarity of arthropod community between the control plots with and without chemical insecticide spray was relatively lower.It could be concluded that the effect of Bt rice on the arthropod community was apparently lower than that of chemical insecticides.