不同寄主来源的根虫瘟霉菌株对小菜蛾幼虫的毒力比较  

Comparative virulence of Zoophthora radicans isolates from different hosts against Plutella xylostella larvae

作　　者：刘青娥[1] 徐均焕[1] 冯明光[1] 

机构地区：[1]浙江大学生命科学学院微生物研究所,杭州310029

出　　处：《昆虫学报》2003年第4期447-453,共7页Acta Entomologica Sinica

基　　金：国家自然科学基金项目 ( 3 0 0 70 0 2 5 );教育部"长江学者奖励计划";浙江省自然科学基金项目 ( 3 0 2 0 16)

摘　　要：在不同寄主来源的 4株根虫瘟霉Zoophthoraradicans对小菜蛾Plutellaxylostella 2龄幼虫的生物测定中 ,发现源于小菜蛾的菌株ARSEF110 0毒力最强 ,在 0 5 3～ 319 32 mm2 的孢子剂量下 ,接种后第 8天累计死亡率为 2 38%～ 97 4 4 % ,虫尸全部表现典型的虫瘟霉症状 ;源于叶蝉的ARSEF2 6 99和F9910 1菌株的同日累计死亡率分别为 2 38%～ 5 0 0 0 % (剂量为 1 5 6～314 84 mm2 孢子 )和 2 38%～ 5 7 89% (剂量为 1 84～ 4 84 0 8 mm2 的孢子 ) ;而源于菜粉蝶的ARSEF1342菌株在 3 5 4～6 33 4 0 mm2 的孢子剂量下只引发 6 5 2 %～ 13 6 3%的累计死亡率 ,后 3个菌株致死的小菜蛾幼虫仅部分表现典型症状。所获数据经时间 剂量 死亡率模型模拟分析 ,剂量效应参数依次为ARSEF110 0 (1 89) >F9910 1(1 4 8) >ARSEF2 6 99(1 2 3) >ARSEF1342 (0 37) ,相互间差异均达极显著水平。接种后 4～ 8天内 ,ARSEF110 0的LD50 值分别为 2 31 6 8、 113 0 8、 71 4 1、4 0 87和 35 30 mm2 的孢子 ,其毒力远高于其余 3个菌株 ;ARSEF2 6 99的相应LD50 值为 1344 4 3、 92 2 39、 5 5 5 5 8、 4 10 0 6和397 0 7 mm2 的孢子 ;F9910 1的LD50 值为 6 6 6 86、 4 5 1 6 4、 4 13 82、 35 0 6 5和 332 5 7Four Zoophthora radicans (Entomophthorales) isolates from different hosts were bioassayed against the second instar larvae of the diamondback moth, Plutella xylostella in the laboratory. Each isolate included eight dosages resulting from spore showers at different times. On day 8 after exposure to a spore shower for inoculation, a P. xylostella derived isolate, ARSEF1100, caused a cumulative mortality of 2 38%-97 44% at 0 53-319 32 conidia/mm 2 with all cadavers exhibiting typical Zoophthora syndrome. Two isolates derived from Empoasca, ARSEF2699 and F99101, killed 2 38%-50 00% and 2 38%-57 89% at 1 56-314 84 and 1 84-484 08 conidia/mm 2, respectively, whereas the isolate ARSEF1342 from Pieris brassicae, killed only 6 52%-13 63% at 3 54-633 40 conidia/mm 2. Typical Zoophthora syndrome was observed only in approximately one third of cadavers killed by the latter three isolates. Fitting the data to a time dose mortality model generated the estimates of parameters for time and dose effects of each isolate. The parameter estimates for dose effect (β) was 1 89 for ARSEF1100, 1 48 for F99101, 1 23 for ARSEF2699, and 0 37 for ARSEF1342, which are significantly different. The LD 50 values estimated for ARSEF1100 were 231 68,113 08, 71 41, 40 87 and 35 30 conidia/mm 2 on days 4-8 after exposure, respectively. The corresponding estimates were 1 344 43,922 39,555 58,410 06 and 397 07 conidia/mm 2 for ARSEF2699, and 666 86,451 64,413 82,350 65 and 332 57 conidia/mm 2 for F99101 The virulence for ARSEF1342 was too weak for its LD 50 to be estimated. The isolate ARSEF1100 was the most virulent to P. xylostella, and can be considered as a microbial agent for control of the pest.

关 键 词：根虫瘟霉 小菜蛾 时间 剂量 死亡率模拟 毒力 虫瘟霉症 

分 类 号：Q965.9[生物学—昆虫学]