绿僵菌素的分离制备及其对蛴螬的毒力

以金龟子绿僵菌金龟子变种Metarhizium anisopliae var. anisopliae菌株MaQ10发酵液为材料，采用萃取、浓缩、制备色谱及重结晶技术，分离纯化出5种绿僵菌素的晶体，经与标准样品以及参考文献相对照，此5种晶体与绿僵菌素A、A2、B、C和E相吻合。进而，采用浸渍法测定了绿僵菌素A和B对大等鳃金龟Exolontha serrulata (Gyllenhall) 和卵圆齿爪鳃金龟Holotrichia ovata Chang 1龄幼虫的触杀毒力。结果表明： 绿僵菌素A和B对大等鳃金龟的触杀活性，在处理后96～120 h内最高，LC₅₀分别为78.1571 mg/L和88.7562 mg/L； 处理浓度为300 mg/L时，LT₅₀分别为13.4159 h和10.5331 h。绿僵菌素A和B对卵圆齿爪鳃金龟的触杀活性，在处理后96 h时最高，LC₅₀分别为66.5308 mg/L和79.4309 mg/L；处理浓度为300 mg/L时，LT₅₀分别是13.6399 h和9.9451 h。

Purification of destruxins produced by Metarhizium anisopliae and bioassay of their insecticidal activities against grubs

Five crystal destruxins were purified from the fermentation broth of Metarhizium anisopliae var.anisopliae strain MaQ10 via preparative HPLC and re-crystalization,which were classified to destruxin A,B,C,E and A_2,respectively.Contact toxicities of destruxins A and B against the grubs Exolontha serrulata(Gyllenhall)and Holotrichia ovata Chang were bioassayed by immersing the insects in aqueous dilutions.The results indicated that at 96 and 120 h after treatment,the LC_ 50s of destruxins A and B were estimated as 78.1571 mg/L and 88.7562 mg/L towards E.serrulata and 66.5308 mg/L and 79.4309 mg/L towards H.ovata,respectively.At the concentration of 300 mg/L,the LT_ 50s of destruxins A and B were 13.4159 h and 10.5331 h towards E.serrulata,and 13.6399 h and 9.9451 h towards H.ovata,respectively.