玫烟色虫草IF-1106菌株对小菜蛾致病力及时间-剂量-死亡率模型分析  

Observation of Pathogenicity of Cordyceps fumosorosea IF-1106 against Plutella xylostella and Analysis of a Time-Dose-Mortality Model

作　　者：田晶[1,2] 孟豪[2] 马瑞燕[2] TIAN Jing;MENG Hao;MA Ruiyan(Department of Biological and Food Engineering,Lüliang University,Lishi Shanxi 033001,China;College of Plant Protection,Shanxi Agricultural University,Taigu Shanxi 030801,China)

机构地区：[1]吕梁学院生物与食品工程系,山西离石033001 [2]山西农业大学植物保护学院,山西太谷030801

出　　处：《西北农业学报》2025年第4期726-732,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：国家现代农业产业技术体系(CARS-28);山西省高等学校科技创新计划(2021L566);吕梁市科技计划(2023NYYF14)。

摘　　要：为获得对小菜蛾(Plutellaxylostella)具有高毒力的虫生真菌并将其应用于生产,采用喷雾法测定玫烟色虫草(Cordycepsfumosorosea)对小菜蛾幼虫的致病力,观察小菜蛾3龄幼虫的感病症状,并运用时间-剂量-死亡率模型分析玫烟色虫草IF-110^(6)菌株对小菜蛾幼虫的时间效应和剂量效应。结果表明:小菜蛾3龄幼虫接种玫烟色虫草IF-110^(6)菌株5~7d后,虫体全身被菌丝包被,并缩小且变得干瘪,体色呈黑褐色。不同浓度的玫烟色虫草孢子悬浮液处理小菜蛾2~4龄幼虫后,所有龄期都会感染而发病死亡。在孢子浓度为1.0×10^(8)cfu/mL时,2、3、4龄幼虫处理7d后的累计校正死亡率分别为94.12%、88.89%、78.95%。运用时间-剂量-死亡率模型对生物测定数据进行拟合,通过Hosmer-Lemeshow拟合异质性检验,并估计该菌株对小菜蛾的致死剂量与致死时间。随着接种天数的增加,相应的LD50和LD90随之降低,剂量效应逐渐增强,致死时间与剂量对数有关,2龄幼虫的LT50在1.0×10^(6)~1.0×10^(8)孢子/mL范围内由4.77d降到2.89d。由此可见,玫烟色虫草IF-110^(6)菌株对小菜蛾的生物防治具有较好的应用潜力。To identify an entomogenous fungus with high virulence against Plutella xylostella and evaluate its potential for field application,a spray method was used to assess the pathogenicity of Cordyceps fumosorosea against P.xylostella larvae.Infection symptoms in third instar larvae were observed,and the time-dose-mortality(TDM)model was used to analyze the time and dose effects of C.fumosorosea IF-110^(6) on P.xylostella larvae.The results showed that third-instar P.xylostella larvae,inoculated with strain IF-110^(6),were entirely encased in mycelium within 5-7 days,which led to body shrinkage and dark brown discoloration.After treatment with different concentrations of C.fumosorosea spore suspension,larvae across all instars became infected and subsequently died.At the spore concentration of 1.0×10^(8)cfu/mL,the cumulative corrected mortality rates reached 94.12%,88.89%and 78.95%for second,third and fourth instars,respectively,after 7 days of treatment.Fitting of the TDM model to bioassay data,validated by the Hosmer-Lemeshow heterogeneity test was,allowed for estimation of of lethal doses(LD)and lethal times(LT)for P.xylostella.With prolonged exposure,both LD50 and LD90 values declined,indicating an intensified dose effect;the logarithmic relationship between dose and mortality time revealed that the LT50 of second-instar larvae decreased from 4.77 days to 2.89 days as spore concentrations ranged from 1.0×10^(6) to 1.0×10^(8) spores/mL.The strain IF-110^(6) of C.fumosorosea exhibit a promising potential for biological control of P.xylostella.

关 键 词：玫烟色虫草 小菜蛾 致病力 感病症状 时间-剂量-死亡率模型 生物防治 

分 类 号：S476.12[农业科学—农业昆虫与害虫防治]