苏云金芽孢杆菌LY30菌株对棉铃虫毒性的研究

目的]研究苏云金芽孢杆菌LY30菌株对棉铃虫的毒性作用。方法]初步比较LY30和HD-1菌株的形态特征、生理生化特性,并采用生物测定的方法,比较它们对棉铃虫初孵、二龄、三龄幼虫的毒效差异。结果]LY30属于H3a3b3c血清型、kurstaki亚种,主要由135、65kD2种蛋白成分组成,在菌株生长形态、发酵培养特征、生理生化特性方面与生产菌株HD-1差别不大。LY30菌株发酵液对棉铃虫初孵、二龄、三龄幼虫的LC50分别为0.32、0.62、2.58μl/ml。结论]LY30菌株对棉铃虫三龄以下的幼虫具有高毒力。

Study on the Toxicity of Bacillus thuringiensis LY30 to Cotton Bollworm

The study aimed to explore the toxicity of Bacillus thuringiensis(Bt) LY30 to cotton bollworm.A high toxicity Bt strain against larvae of cotton bollworm named as LY30 was isolated from over 400 wild-type strains by bioassay.The initial comparison of LY30 with HD-1 by morphological,physiological,biochemical features showed that LY30 belongs to H3a3b3c serotype.SDS-PAGE electrop horesis atlas showed that they were composed of two kinds of protein of 135kD and 65kD components.There were no differences between growt hmorphology,fermentation culture features,physiological and biochemical characteristics between HD-1 and LY30.However,toxicity difference between them was examined with bioassay,the result showed that LC50 of LY30 fermented liquid against neonate,second and third instar larvae of cotton bollworm were 0.32,0.62,and 2.58 μL/ml respectively.LY30 possesses high toxicity against larvae of cotton bollworm younger than third instar.