荧光增白剂对苏云金芽孢杆菌毒力的增效作用及其紫外防护功效

Studies on Synergism and Photodegradation of Bacillus thuringiensis by Fluorescent Brighteners in Helicoverpa armigera Larvae

测试了 3种荧光增白剂 Tinopal LPW,VBL和 JD- 3对苏云金杆菌杀虫剂杀棉铃虫初孵幼虫毒力的影响 ,并检测了荧光增白剂 VBL作为佐剂在 Bt受紫外线照射时的光保护功效。结果表明 ,这 3种二苯乙烯类荧光增白剂以 1 0 g/kg与 Bt复配后的 LC50 值与不加荧光增白剂的Bt的 L C50 值相比 ,其增效比值分别为 :1 .2 3、1 .49和 2 .0 0。说明这 3种荧光增白剂对 Bt杀棉铃虫的活性有不同程度的增效作用。而且复混剂 (1 0 g/kg荧光增白剂 VBL+ Bt)在紫外线处理8h后 ,其杀虫活性仍保持 70 %以上 ,说明了荧光增白剂 VBL是 Bt一种好的光保护剂 。

Primary studies were designed to determine the effect of three fluorescent brighteners, Tinopal LPW, JD 3 and VBL, on the infectivity of Bacillus against neonates of Helicoverpa armigera. Furthermore, the fluorescent brightener VBL was tested as photodegradation for B. thuringiensis. The results showed that the LC 50 of Bt declined from 1.23 to 2.00 fold with the addition of 10g/kg fluorescent brighteners. The magnitude of reduction in LC 50 in H. armigera larvae indicated that selected brighteners enhanced the virulence of Bt insecticides in varying degrees. Moreover, the adjuvant VBL at different concentration provided effective protection when Bt was exposed to UV irradiation (i.e.>70% original activity remained).