摘要
开展草地贪夜蛾病原真菌的筛选和毒力测定可为草地贪夜蛾的绿色防控提供新的生物制剂。本研究从广西南宁田间采集的草地贪夜蛾幼虫僵虫上分离获得一株病原真菌,采用形态学和ITS-rDNA序列分析相结合的方法对该菌株进行了鉴定,并采用浸虫法测定了该菌株对草地贪夜蛾的致病力。结果表明新分离的菌株为莱氏绿僵菌Metarhizium rileyi,编号为CDTLJ1;该菌株对草地贪夜蛾幼虫、预蛹、蛹均有致病力,1.20×10^(7)孢子/mL浓度下,接菌处理后第6 d,2~5龄幼虫的累积校正死亡率均达100%,6龄幼虫的累积校正死亡率为98.33%,预蛹和蛹的累积校正死亡率分别为28.33%、20.00%,草地贪夜蛾2~6龄幼虫的LT_(50)值从3.91 d升至4.24 d;菌株CDTLJ1对草地贪夜蛾3龄幼虫的致死率随孢子悬浮液浓度的升高而增加,当浓度达1×10^(8)孢子/mL时,幼虫的致死LT_(50)为4.10 d,接菌处理后第6 d,3龄幼虫的累积校正死亡率达100%,LC_(50)为1.12×10^(4)孢子/mL。结果表明,莱氏绿僵菌CDTLJ1对草地贪夜蛾有良好的生防潜力,具有进一步深入研究和开发利用的前景。
It is crucial for green prevention and control of Spodoptera frugiperda to collect and screen biocontrol strains with high virulence against S.frugiperda.In this study,a fungus was isolated from diseased larvae of S.frugiperda collected in Nanning,Guangxi.The species was identified using morphological characterization and ITS-rDNA sequence analysis,and the pathogenicity of the strain to the larvae,prepupa,and pupa of S.frugiperda were determined by immersion method in the laboratory.The pathogen was identified as Metarhizium rileyi,named CDTLJ1,could infect the larvae,prepupa,and pupa of S.frugiperda.The 1.20×10^(7) conidia/mL concentration treatment caused 100%,100%,100%,100%,98.33%,28.33%,and 20.00%corrected mortality of 2^(nd),3^(rd),4^(th),5^(th) and 6^(th) instar larvae,prepupa,and pupa on the 6^(th) day post treatment,and resulted in median lethal time(LT_(50))values of 3.91 d—4.24 d for the 2^(nd) to 6^(th) instar larvae.The mortality rate of the 3^(rd) instar larvae caused by infection of M.rileyi strain CDTLJ1 increased with the rising of concentration of conidial suspension.When the concentration reached 1×10^(8) conidia/mL,LT_(50) was 4.10 d,the corrected accumulative mortality reached 100%and the median lethal concentration(LC_(50))was 1.12×10^(4) conidia/mL on the 6^(th) day post treatment.These results show that the M.rileyi strain CDTLJ1 has a high biocontrol potential for use against S.frugiperda and deserves further research and utilization.
作者
龙秀珍
高旭渊
曾宪儒
何瞻
韦德卫
江小冬
曾涛
于永浩
LONG Xiuzhen;GAO Xuyuan;ZENG Xianru;HE Zhan;WEI Dewei;JIANG Xiaodong;ZENG Tao;YU Yonghao(Plant Protection Research Institute,Guangxi Academy of Agricultural Sciences/Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests/Crop Pest Scientific Observation and Experimental Station of Nanning,Ministry of Agriculture and Rural Affairs,Nanning 530007,China)
出处
《中国生物防治学报》
CSCD
北大核心
2021年第6期1111-1119,共9页
Chinese Journal of Biological Control
基金
国家重点研发计划(2019YFD0300105)
广西自然科学基金(2017GXNSFBA198146)
广西农业科学院基本科研业务专项(桂农科2021YT067,桂农科2020YM95)
广西作物病虫害生物学重点实验室系统课题(2020-ST-01)。
关键词
草地贪夜蛾
莱氏绿僵菌
毒力
鉴定
Spodoptera frugiperda
Metarhizium rileyi
virulences
identification
