真菌新型激活蛋白对Bt制剂的增效作用

Enhancement of A New Activator Protein to Bacillus thuringiensis

激活蛋白是从交链孢属 (Alternaria)真菌分离的新型多功能蛋白 ,以棉铃虫和小菜蛾幼虫为供试昆虫 ,用饲料染毒法、浸叶法和浸虫法测定了激活蛋白对Bt的增效作用。结果表明 ,用Bt∶激活蛋白为 1∶0 0 3的含毒饲料饲喂 2龄棉铃虫幼虫 ,其增效指数为 2 2倍。Bt∶激活蛋白以 1∶0 0 95和 1∶0 6混合后分别浸叶后 ,饲喂棉铃虫和小菜蛾幼虫 ,其增效指数分别为 2 7和 5 5倍。单独用激活蛋白饲喂棉铃虫幼虫无致死活性 ,但当Bt与激活蛋白以 1∶0 75混合后 ,毒杀效果显著增强 ,对Bt的增效指数为 18 5倍。

A novel activator protein was isolated from Alternaria. Experiment showed that it could enhance the activity of Bt (Bacillus thuringiensis) significantly. The Synergia was 2.2 fold for Helicoverpa armigera while 2^(nd) instar larvae were fed with artificial medium containing the mixture of Bt and activator at a rate of 1∶0.03 (W/W). The Synergia was 2.7 fold for 3^(rd) larvae of H. armigera and was 5.5 fold for 3^(rd) larvae of Plutella xylostella, while both insect larvae fed with plant leave pre-soaked in the solution of Bt and activator protein at the ratios of 1∶0.095 or 1∶0.6, respectively. Test showed that activator protein alone was no insecticidal activity to the larvae of H. armigera by insect dipping method, however, 18.5-fold activity enhancement could be obtained while Bt mixed with activator protein at a rate of 1∶0.75.