一株球孢白僵菌的分离鉴定及其对草地贪夜蛾的致病性  

Isolation and identification of a Beauveria bassiana isolate and its pathogenicity to Spodoptera frugiperda(Lepidoptera:Noctuidae)

作　　者：雷妍圆[1] 章玉苹[1] 薛志洪 王裕华 黄少华[1] 吕利华[1] LEI Yan-Yuan;ZHANG Yu-Ping;XUE Zhi-Hong;WANG Yu-Hua;WANG Shao-Hua;L Li-Hua(Guangdong Provincial Key Laboratory of High Technology for Plant Protection,Institute of Plant Protection,Guangdong Academy of Agricultural Sciences,Guangzhou 510640,China;Guangdong Academy of Agricultural Sciences,Guangzhou 510640,China;College of Agriculture,South China Agriculture University,Guangzhou 510642,China)

机构地区：[1]广东省农业科学院植物保护研究所/广东省植物保护新技术重点实验室,广州510640 [2]广东省农业科学院,广州510640 [3]华南农业大学农学院,广州510642

出　　处：《环境昆虫学报》2020年第3期593-601,共9页Journal of Environmental Entomology

基　　金：国家重点研发计划(2019YFD0300104);广东省重点领域研发计划资助(2020B020224002);广东省现代农业产业技术体系创新团队(2019KJ113)。

摘　　要：草地贪夜蛾Spodoptera frugiperda(J.E.Smith)是我国于2019年新发现的一种迁飞性重大害虫。为了寻找对草地贪夜蛾有高致病性的昆虫病原真菌,本实验对采自广东省广州市华南农业大学湿地的感菌稻黑蝽Scotinophara lurida若虫僵虫进行了室内分离培养,结合形态学和rDNA-ITS序列分析,采用浸虫法研究了该菌对草地贪夜蛾各龄幼虫的致病力。鉴定结果表明该病原真菌为球孢白僵菌Beauveria bassiana,编号为GZSL-1菌株。菌株GZSL-1可侵染草地贪夜蛾6个龄期的幼虫,随孢子浓度的升高,草地贪夜蛾幼虫感病死亡率增加,当浓度达到1×10^8孢子/mL时,1~3龄幼虫的累计校正死亡率皆为100%,4龄和5龄幼虫也达到57.47%和55.06%,6龄仅25.28%。接菌6 d后1~5龄幼虫的LC 50值分别为1.32×10^3、3.42×10^3、1.01×10^4、1.61×10^5和1.23×10^7孢子/mL。幼虫LT50值随孢子悬浮液浓度增加而递减,在孢子浓度为1.0×10^4~1.0×10^8孢子/mL范围内,1龄、2龄和3龄幼虫的LT50值分别为3.58~1.69 d、4.30~1.78 d和5.70~3.12 d;浓度为1.0×10^5~1.0×10^8孢子/mL时,对4龄幼虫的LT50为5.45~4.85 d;浓度为1.0×10^7~1.0×10^8孢子/mL时,对5龄幼虫的LT50为5.04~5.02 d。上述研究结果表明,鉴定的球孢白僵菌菌株GZSL-1对草地贪夜蛾幼虫具有较强致病性,可为草地贪夜蛾微生物防治提供候选菌种资源。The fall armyworm,Spodoptera frugiperda(J.E.Smith)(Lepidoptera:Noctuidae),is a newly global migratory pest to China in 2019.To enrich the resource of entomopathogenic fungi for S.frugiperda biocontrol,fungi infected Scotinophara lurida nymphs were collected from wetland in South China Agricultural University,Guangzhou City,Guangdong Province.The strain were isolated,and the species was identified based on morphological and rDNA-ITS sequence analysis,the pathogenicity of the strain to S.frugiperda larvae was studied in laboratory by immersing larvae of different instars into serial concentrations of conidial suspension.Results showed that this strain was identified as Beauveria bassiana,named GZSL-1.Larvae from 1 st to 6 th instar were infected by B.bassiana strain GZSL-1.The mortality rates of the S.frugiperda caused by infection of B.bassiana increased with the concentration of conidial suspension and the time after treatment.The highest concentration(1×10^8 conidia/mL)treatment caused 100%,100%,100%,57.47%,55.06%,and 25.28%corrected mortality for 1 st to 6 th instar larvae on the 6 th day,respectively.The estimated LC 50 values of 1 st to 5 th instar larvae on day 6 after treatment were 1.32×10^3,3.42×10^3,1.01×10^4,1.61×10^5,and 1.23×10^7 conidia/mL,respectively.Values of LT50 of all tested instars were shortened with concentration.The LT50 values of 1 st,2 nd and 3 rd instar were 3.58~1.69 days,4.30~1.78 days,and 5.70~3.12 days,respectively,in the range of 1×10^4~1×10^8 conidia/mL.The LT50 values of 4 th instar were 5.45~4.85 days in the range of 1×10^5~1×10^8 conidia/mL.The LT50 values of 5 th instar were 5.04~5.02 days in the range of 1×10^7~1×10^8 conidia/mL.The results suggested that the B.bassiana strain GZSL-1 is a promising candidate for use in microbial control of S.frugiperda.

关 键 词：球孢白僵菌 草地贪夜蛾 昆虫病原真菌 鉴定 致病力 

分 类 号：Q965.9[生物学—昆虫学] S433.4[农业科学—农业昆虫与害虫防治]