一株引起田间昆虫流行病的虫生真菌的多基因序列鉴定

本研究采用形态学鉴定、单基因、多基因序列系统发育进化分析等方法对引起山东临沂地区的白菜地夜蛾科昆虫流行病的病原真菌进行鉴定,明确了此病原真菌的系统分类地位。通过菌株的菌落特征、培养特征和产孢特性初步确定引起山东临沂地区夜蛾科昆虫流行病的病原菌系绿僵菌属Metarhizium spp.,通过多基因序列测定、系统发育进化分析,进一步确定引起流行病的菌株为莱氏绿僵菌Metarhizium rileyi,菌株命名为SDMr01。用浓度为1.0×108个/mL的SDMr01孢子悬浮液分别浸泡小菜蛾Plutella xylostella及斜纹夜蛾Spodoptera litura 2龄幼虫进行致病性测定,14 d后累计校正死亡率分别为77.1％、80.5％。结果表明,莱氏绿僵菌SDMr01对部分夜蛾科害虫具有良好的生防潜力及开发应用前景。

Identification of pathogenic fungus causing field pests epidemics based on multiple-gene sequence analysis

Morphological identification, singular gene and multigene phylogenetics methods were used to identify entomogenous fungi which lead to Noctuidae epidemics in China cabbage field in Linyi, Shandong province. Morphological observation indicated that the entomogenous fungus was Metarhizium. Molecular phylogenetic analysis confirmed that the entomogenous fungus was Metarhizium rileyi, named as SDMr01. The mortalities of 2nd instar larvae of Plutella xylostella and Spodoptera litura infected by 1.0×108 spore/mL SDMr01 suspension were respectively measured by immersion method. The corrected accumulative mortalities rate reached 77.1% and 80.5% 14 days after treatment, respectively. The results demonstrated SDMr01 had good biocontrol potential and application prospects against some Noctuid insects.