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期 刊 ：植物保护学报 2010年

关键词：苏云金芽孢杆菌；cry9Aa基因；克隆；生物活性；

Keywords:Bacillus thuringiensis, cry9Aa gene, cloning, insecticidal activity,

摘 要 ：为了解决目前广泛使用的cry1A类基因的抗性问题,获得对鳞翅目害虫高效杀虫基因,从菌株SC5D2和T03C001中鉴定并克隆到了2个新型cry9Aa基因,被Bt国际命名委员会分别正式命名为cry9Aa3和cry9Aa4,并进一步对其编码的蛋白进行活性测定。结果显示,2个基因对小菜蛾、玉米螟均具有较高的杀虫活性,其中对小菜蛾的LC₅₀分别为1.83μg/mL和1.90μg/mL,对玉米螟的LC₅₀分别为6.93μg/mL和1.06μg/mL。同时,两种Cry9Aa蛋白对Cry1Ac抗性小菜蛾都具有较高的杀虫活性,LC₅₀分别为1.74μg/mL和1.39μg/mL,与敏感小菜蛾杀虫活性测定数据相当,表明Cry9Aa与Cry1Ac没有交互抗性。

Abstract:To solve the resistance risk problem of the widely applied cry1A gene and screen high toxic Lepidoptera specific cry genes, two cry9Aa genes from strain SC5D2 and T03C001 were identified and cloned respectively. The two genes were designated as cry9Aa3 and cry9Aa4 by International Nomenclature Committee of Bt Endotoxin. Furthermore, the toxicity of the two genes was evaluated. The results indicated that both the two toxins had high insecticidal activities against Plutella xylostella and Ostrinia furnacalis. The toxicity of the two toxins to P.xylostella with LC₅₀ were 1.83μg/mL and 1.90μg/mL respectively while to O.furnacalis with LC₅₀ were 6.93μg/mL and 1.06μg/mL. Also, the two toxins had high insecticidal activities against Cry1Ac-R P.xylostella strain with LC₅₀ of 1.74μg/mL and 1.39μg/mL, respectively, similar to that against Cry1Ac-S P.xylostella strain. The results suggested that Cry9Aa toxin exhibited no cross-resistant to Cry1Ac toxin against P.xylostella.

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