4种病原真菌对桃蚜和温室白粉虱的致病力

Pathogenicity of Four Pathogenic Fungi to Myzus persicae and Trialeurodes vaporariorum

首先对采集的罹病桃蚜(Myzus persicae)和温室白粉虱(Trialeurodes vaporariorum)虫尸病原真菌进行分离纯化,通过形态学和rDNA-ITS序列分析,鉴定结果分别为长孢蜡蚧菌[Lecanicillium longisporum(JL-006)]和蜡蚧轮枝菌[Akanthomyces lecanii(JL-007)]。为了评估其生防潜能,采用浸渍法比较研究了其与渐狭蜡蚧菌[Lecanicillium attenuatum(JL-003)]和球孢白僵菌[Beauveria bassiana(JL-005)]4种病原真菌对桃蚜和温室白粉虱3龄若虫的致病力。结果表明:菌液孢子浓度1.0×10^(8)/mL致病力要明显高于1.0×10^(5)/mL。当孢子浓度为1.0×10^(8)/mL时,球孢白僵菌JL-005和长孢蜡蚧菌JL-006对桃蚜具有较强致病性,10 d死亡率分别为71.8%和74.5%,LT_(50)分别为5.6 d和5.5 d;而球孢白僵菌JL-005和蜡蚧轮枝菌JL-007对温室白粉虱具有较强致病性,10 d死亡率分别为82.3%和80.5%,LT_(50)分别为5.4 d和5.1 d。研究结果可为桃蚜和温室白粉虱的防治提供候选菌种资源,并为后续温室害虫"一菌多防"技术开发提供技术支撑。

This study isolated and purified two strains JL-006 and JL-007 firstly from naturally entomopathogen-infected Myzus persicae and Trialeurodes vaporariorum,which were identified to be Lecanicillium longisporum and Lecanicillium lecanii by morphology and rDNA-ITS sequence analysis.To assess the biological control potential,the pathogenicity of JL-006 and JL-007 with another two fungal strains Lecanicillium attenuatum JL-003 and Beauveria bassiana JL-005 to 3 rd-instar nymphs of M.persicae and T.vaporariorum were determined using the dipping method.The results indicated that the virulence was higher at the concentration of 1.0×10^(8)conidia/mL than at 1.0×10^(5)conidia/mL.The strains B.bassiana JL-005 and L.longisporum JL-006 were promising candidates for biological control of M.persicae with the higher mortalities of 71.8%and 74.5%,and the lower LT_(50)values of 5.6 d and 5.5 d,respectively,after inoculation for 10 days.Meanwhile,the strains B.bassiana JL-005 and L.lecanii JL-007 were promising candidates for biological control of T.vaporariorum with the higher mortalities of 82.3%and 80.5%,and lower LT_(50)values of 5.4 d and 5.1 d,respectively.Our results provide a technical support for simultaneously suppressing several insect pests by a pathogenic fungus in greenhouse.