一株侵染松墨天牛幼虫的球孢白僵菌的分离鉴定

Isolation and Identification of a Beauveriabassiana Strain from the Infected Larvae ofMonochamus alternatus in the Pine Forest

于2023年,对采自武夷山国家公园的松墨天牛(Monochamus alternatus)幼虫僵虫的寄生真菌进行分离培养,获得1株虫生真菌(BbWYZ-06),利用形态学观察和系统发育分析对该菌株进行鉴定,并测定该菌株的生物学特性以及对松墨天牛幼虫的致病性。结果表明,菌株BbWYZ-06的培养特征与白僵菌属球孢白僵菌较为一致,基于核糖体内转录间隔区(internal transcribed spacers, ITS)和RNA聚合酶Ⅱ的第2亚基(the second largest subunit of the nuclear RNA polymerase enzymeⅡ,RPB2)序列构建系统发育树,该菌株与球孢白僵菌(Beauveria bassiana)聚在同一分支,因此将菌株BbWYZ-06鉴定为球孢白僵菌。在25℃下,菌株BbWYZ-06在PDA培养基上的菌落生长速率为(2.54±0.25) mm·d^(-1),培养第15天时的产孢量为(2.11±0.23)×10^(8)个·cm^(-2)。菌株BbWYZ-06对松墨天牛幼虫具有较强的致病性,孢子悬浮液为1.0×10^(7)个·mL^(-1)时,松墨天牛幼虫第7天累计死亡率达93%,LT50值为3.95 d,在松墨天牛生物防治中具有良好的应用潜力。

In order to identify the strain BbWYZ-06 of entomopathogenous fungi isolated from the infected larva of Monochamus alternatus,whic h was collected from the Wuyishan National Park in 2023,its morphological characteristics and p hylogenetic analysis were performed,and its biological characteristics and path ogenicity were studied.The BbWYZ-06 strain was identified as Beauveria bassiana based on morphological characteristics and molecular identifica tion of the part ial sequences of internal transcribed spacers(ITS)and the second largest subun it of the nuclear RNA polymerase enzymeⅡ(RPB2).Under 25℃,the daily growth rate of colony diameter of BbWYZ-06 was(2.54±0.25)mm·d^(-1),and its s pore prod uction per unit area was(2.11±0.23)×10^(8) spore·cm^(-2) after cultu red on PDA for 15 days.The accumulated mortality of the larvae of M.alternatus in seven days reached 93%at the concentration of 1.0×10^(7) spore·mL^(-1),and the LT 50 va lue was 3.95 d.The B.bassiana strain BbWYZ-06 showed high vir ulence to the larvae of M.alternatus.These results indicated t hat B.bassiana BbWYZ-06 will be potentia lly one of biocontrol agents against M.alternatus in the pine f orests.