侵染松墨天牛幼虫的虫生真菌鉴定及致病性测定

Identification of entomopathogenous fungus isolated from the infected larva of Monochamus alternatus and pathogenicity test

从自然罹病的1头松墨天牛Monochamus alternatus幼虫僵虫中分离纯化得到1株虫生真菌MX-04。采用形态学和分子生物学相结合的方法对其进行鉴定,测定其生物学特性及其对松墨天牛幼虫的致病性。结果表明:菌株MX-04为粉质虫草Cordyceps farinosa,在25℃下培养14 d后产孢量为(8.39±1.03)×10^(7)个/cm^(2);菌株MX-04对松墨天牛幼虫具有较高的致病力,松墨天牛3龄幼虫接种13 d后死亡率达86.67%,LT_(50)值为6.80 d。菌株MX-04具有开发为松墨天牛生防制剂的良好潜力。

The strain MX-04 of entomopathogenous fungi was isolated from the infected larva of Monochamus alternatus.Morphological and molecular biological methods were performed,and its biological characteristics and pathogenicity were studied.The results showed that strain MX-04 was identified as Cordyceps farinosa.The spore production of strain MX-04 was(8.39±1.03)×10^(7)spore/cm^(2)14 days after culture on PDA at 25℃.The C.farinosa strain MX-04 showed high virulence to the larvae of M.alternatus.The mortality of the third instar larvae of M.alternatus reached 86.67%13 days after inoculation,and the LT_(50 )value was 6.80 d.The strain MX-04 has the good potential to be developed as biocontrol agents for M.alternatus.