本文選題：蘇云金芽孢桿菌以色列亞種　切入點：致乏庫蚊　出處：《華中農(nóng)業(yè)大學(xué)》2005年碩士論文

【摘要】：蚊子是傳播人類疾病的重要媒介昆蟲之一。滅蚊劑的發(fā)展經(jīng)歷了礦物油、植物粉和化學(xué)殺蟲劑到微生物滅蚊劑等階段。幼蟲時期是防治蚊蟲的關(guān)鍵時期。蘇云金芽孢桿菌以色列亞種(Bacillus thuringiensis subsp．israelensis，簡稱Bti)以其對蚊科幼蟲高毒，且高效安全、易于分解、低殘留、與環(huán)境相容的特性，成為被廣泛關(guān)注的新的滅蚊劑的代表。 為了了解Bti對致乏庫蚊幼蟲的作用特性及對主要病媒蚊蟲的防治效果，本試驗主要采用生物測定的方法，對Bti的兩個菌株IPS82和KN-11對致乏庫蚊幼蟲的毒力進(jìn)行比較，并對菌株IPS82在產(chǎn)芽孢培養(yǎng)基中的發(fā)酵特征和環(huán)境因素對毒力的影響進(jìn)行了試驗研究。 Bti對致乏庫蚊幼蟲的作用特性表明：Bti IPS82和KN-11對致乏庫蚊蚊蟲均有較高的致死率，，LC_(50)(24h)分別為23.7 mg／L和33.6 mg/L。Bti IPS82在實驗室發(fā)酵36h可達(dá)最大毒力LC_(50)24.2 mg／L，且發(fā)酵過程中的菌體密度、芽孢形成、溶解氧消耗和蚊幼蟲的致死率變化之間具有密切聯(lián)系。IPS82發(fā)酵液應(yīng)用的環(huán)境因素中，光照的影響最大，可使其蚊幼蟲的致死率半衰期從21d縮短至10d：環(huán)境溫度在15℃～30℃內(nèi)變化，Bti使蚊幼蟲的致死率都保持在50％左右。當(dāng)環(huán)境溫度35℃時，Bti使蚊幼蟲的致死率再提高16％：環(huán)境pH偏離7～11時，IPS82的蚊幼蟲的致死率從66.7％下降至40％左右，環(huán)境pH3時其蚊幼蟲的致死率下降至16％：在一定的幼蟲密度(低于30條／100mL)范圍內(nèi)IPS82發(fā)酵液的蚊幼蟲的致死率穩(wěn)定，幼蟲密
[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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