松墨天牛优良球孢白僵菌菌株生物学及毒力研究

 对松墨天牛Monochamus alternatus优良球孢白僵菌Beauveria bassiana菌株B_xs的营养生长、产孢条件以及对松墨天牛毒力进行研究。试验表明：B_xs菌株营养生长温度范围为20～30 ℃，最适宜营养生长和产孢温度均为25 ℃，35 ℃下营养生长停止；适合菌株B_xs的营养生长和产孢的培养基为DPSA。毒力测定表明：不同松墨天牛虫龄和虫态间感病性差异较大（P＜0.05），虫龄越小越容易感病。B_xs菌株对3龄幼虫的剂量—死亡率方程为y = －1.388 4+0.996 7x，致死中浓度C_L50为3.936 × 10⁶个孢子·L^－1。充分考虑了时间—剂量—死亡率之间的三维关系制作出了菌株对松墨天牛3龄幼虫的互补重对数（CLL）模型。图3表7参11

Biological and virulence study of highly pathogenic Beauveria bassiana on pine sawyer Monochamus alternatus

The colony growth and sporogenous conditions of the highly pathogenic strain B_xs of Beauveria bassiana on pine sawyer Monochamus alternatus，and the virulence of B_xs to pine sawyer Monochamus alternatus were studied. The results showed that the growth temperature for B_xs ranged from 20 to 30 ℃，and 25 ℃ was optimal for both colony growth and sporulation，but the colony growth stopped at 35 ℃. For growth and sporulation，DPSA was the desirable culture medium. Virulence tests indicated that great variations existed in disease susceptibility among different developmental stages of Monochamus alternatus，and higher disease sus-ceptibility occurred in the juvenile stages. The equation of dose-mortality and L_C50 of the third instar were y=-1.388 4+0.996 7x and 3 936 spores·mL^-1 respectively. Based on the Three-dimensional Relation of time-dosage-mortality，a complementary log-log model （CLL model） of B_xs virulence to third instar M. alternatus was constructed.［Ch，3 fig. 7 tab. 11 ref.］