埃及吹绵蚧昆虫病原真菌的筛选、鉴定及其致病性测定  

Screening and identification of the entomopathogenic fungus isolated from Egyptian fluted scale Icerya aegyptiaca and bioassay of its pathogenicity

作　　者：邓嘉茹 孙龙华 毕可可 张劲蔼 唐立鸿 余晓碧 DENG Jiaru;SUN Longhua;BI Keke;ZHANG Jin'ai;TANG Lihong;YU Xiaobi(Guangzhou Institute of Forestry and Landscape Architecture,Guangzhou 510405,Guangdong Province,China)

机构地区：[1]广州市林业和园林科学研究院

出　　处：《植物保护学报》2020年第1期53-64,共12页Journal of Plant Protection

基　　金：广东省省级乡村振兴战略专项-森林资源培育及管护项目(2018KJCX054)

摘　　要：为明确埃及吹绵蚧Icerya aegyptiaca昆虫病原真菌在生物防治中的应用潜力,采用生物测定法筛选得到产孢量高和致病力强的优势分离株,根据形态学特征和rDNA ITS序列分析对优势分离株进行鉴定,并对其室内毒力和温室防效进行测定。结果显示,筛选得到的优势分离株为IJID003,产孢量最高,可达8.51×10^6个/mL,且致病力最强,处理埃及吹绵蚧2龄若虫5 d后,其校正死亡率为95.40%;根据形态学特征和r DNA ITS序列分析鉴定结果,确定该分离株为爪哇棒束孢Isaria javan‐ica。随着分离株IJID003接种浓度的增加,埃及吹绵蚧2龄若虫、3龄若虫和雌成虫的校正死亡率也随之增加,致死中时间LT50则递减;在分生孢子浓度为1.00×10^8个/mL时,其对2龄若虫、3龄若虫和雌成虫的LT50最小,分别为1.89、2.29、2.31 d;随着接种后天数的延长,致死中浓度LC50减小,在接种后6 d,其对2龄若虫、3龄若虫和雌成虫的LC50最小,分别为1.25×10^3、2.04×10^4、8.37×10^5个/mL,表明分离株IJID003对埃及吹绵蚧2龄若虫的毒力较其它2种虫态高;啶虫·毒死蜱2000倍液对埃及吹绵蚧2龄若虫的前期致死速率较快,而分离株IJID003在后期侵染速率较快,处理后6 d两者的防效无显著差异,效果相当。表明爪哇棒束孢分离株IJID003具有产孢量高且致病力强的特点,在埃及吹绵蚧生物防治中具有较好的应用前景。In order to confirm the potential of application of entomopathogenic fungi to biocontrol of Egyptian fluted scale Icerya aegyptiaca,a superior isolate with the most productive sporulation and the strongest pathogenicity among the isolates tested was screened by bioassay and identified based on morphological characters and analysis of rDNA ITS sequences.Its virulence in the laboratory and its control effect on Ic.aegyptiaca in the greenhouse were also determined.The results showed that the superior isolate had the most productive sporulation(8.51×10^6 conidia/mL) and the strongest pathogenicity with a corrected mortality of Ic.aegyptiaca of 95.4% at 5 d after inoculation.The superior isolate was named IJID003 and identified as Isaria javanica based on its morphological characters and molecular identification.The corrected mortality of 2 nd-,3 rd-instar nymphs and female adults of Ic.aegyptiaca increased with the concentration of conidial suspension,while the values of LT50 were decreased;the minimum LT50 values of the isolate IJID003 against 2 nd-,3 rd-instar nymphs and female adults were 1.89,2.29,2.31 d at the concentration of 1.00×10^8 conidia/mL,respectively.The estimated LC50 values were decreased with the duration after inoculation;the minimum LC50 values of the isolate IJID003 against2 nd-,3 rd-instar nymphs and female adults were 1.25×10^3,2.04×10^4,8.37×10^5 conidia/mL at 6 d after inoculation,respectively,which indicated that the isolate IJID003 had high virulence to Ic.aegyptiaca,and its virulence against 2 nd-instar nymph of Ic.aegyptiaca was stronger than against the other two instars.The lethal rate of acetamiprid-chlorpyrifos 2 000 times dilution against 2 nd-instar nymphs of Ic.aegyptiaca was faster than the isolate IJID003 in the early stage,while the isolate IJID003 was faster in the late stage;these two agents had the same control effect at 6 d after inoculation.The superior isolate IJID003 showed an excellent potential for biocontrol of Ic.aegyptiaca.

关 键 词：埃及吹绵蚧 昆虫病原真菌 爪哇棒束孢 分离鉴定 致病力 

分 类 号：S476.12[农业科学—农业昆虫与害虫防治]