苏云金杆菌以色列亚种防治蚊幼虫的应用研究

发布时间：2018-04-09 00:13

  本文选题：苏云金芽孢杆菌以色列亚种　切入点：致乏库蚊　出处：《华中农业大学》2005年硕士论文

【摘要】：蚊子是传播人类疾病的重要媒介昆虫之一。灭蚊剂的发展经历了矿物油、植物粉和化学杀虫剂到微生物灭蚊剂等阶段。幼虫时期是防治蚊虫的关键时期。苏云金芽孢杆菌以色列亚种(Bacillus thuringiensis subsp．israelensis，简称Bti)以其对蚊科幼虫高毒，且高效安全、易于分解、低残留、与环境相容的特性，成为被广泛关注的新的灭蚊剂的代表。 为了了解Bti对致乏库蚊幼虫的作用特性及对主要病媒蚊虫的防治效果，本试验主要采用生物测定的方法，对Bti的两个菌株IPS82和KN-11对致乏库蚊幼虫的毒力进行比较，并对菌株IPS82在产芽孢培养基中的发酵特征和环境因素对毒力的影响进行了试验研究。 Bti对致乏库蚊幼虫的作用特性表明：Bti IPS82和KN-11对致乏库蚊蚊虫均有较高的致死率，，LC_(50)(24h)分别为23.7 mg／L和33.6 mg/L。Bti IPS82在实验室发酵36h可达最大毒力LC_(50)24.2 mg／L，且发酵过程中的菌体密度、芽孢形成、溶解氧消耗和蚊幼虫的致死率变化之间具有密切联系。IPS82发酵液应用的环境因素中，光照的影响最大，可使其蚊幼虫的致死率半衰期从21d缩短至10d：环境温度在15℃～30℃内变化，Bti使蚊幼虫的致死率都保持在50％左右。当环境温度35℃时，Bti使蚊幼虫的致死率再提高16％：环境pH偏离7～11时，IPS82的蚊幼虫的致死率从66.7％下降至40％左右，环境pH3时其蚊幼虫的致死率下降至16％：在一定的幼虫密度(低于30条／100mL)范围内IPS82发酵液的蚊幼虫的致死率稳定，幼虫密
[Abstract]:Mosquitoes are one of the most important vectors of human disease.The development of mosquito-killing agents has gone through mineral oil, plant powder and chemical insecticides to microbial mosquito-killing agents.Larval stage is the key period for mosquito control.Bacillus thuringiensis subsp. israelensis, a subspecies of Bacillus thuringiensis, has become the representative of a new mosquito control agent for its high toxicity to mosquito larvae, high efficiency and safety, easy decomposition, low residue and compatible with the environment.In order to understand the effects of Bti on the larvae of Culex pipiens sativans and to control the main vector mosquitoes, the virulence of two strains of Bti, IPS82 and KN-11, to the larvae of Culex pipiens azaricus was compared by bioassay.The fermentation characteristics of strain IPS82 in spore production medium and the effect of environmental factors on virulence were also studied.The effects of Bti on the larva of Culex pipiens azaricus showed that the death rate of IPS82 and KN-11 to Culex pipiens was higher than that of KN-11 (23.7 mg/L) and 33.6 mg/L.Bti IPS82 (33.6 mg/L.Bti IPS82) reached the maximum virulence of LC_(50)24.2 mg / L in laboratory fermentation for 36 h, and the cell density and spore formation during fermentation.There was a close relationship between the consumption of dissolved oxygen and the mortality of mosquito larvae. Among the environmental factors used in the fermentation broth of IPS82, the effect of light was the greatest.The mortality half life of mosquito larvae was shortened from 21 days to 10 days. The change of environmental temperature at 15 鈩

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