东北地区土壤中高毒力虫生真菌菌株的筛选

Screening of High Virulent Strains of Entomogenous Fungi in Soil of Northeast China

为筛选具有应用价值的高毒力虫生真菌菌株,利用大蜡螟诱集土样中虫生真菌。结果表明：采自中国东北不同生态类型的36份土样中,每份土样3-4龄诱虫30头,14d共有454头感菌,其中克东腾家围子地区土样感菌率最高达80%。虫尸上分离纯化出301份菌株,其中多数为白僵菌,很少数为绿僵菌及其它菌株。其中的41份菌株进行了桃蚜和小菜蛾的室内生物测定,每菌株浓度为1.0×107孢子·mL^-1,菌株JSJ-10、QG1-1、MBD-2、BEE-15、HYD-11、MLX-1和FN-9对桃蚜具高毒力,喷雾7d后的校正死亡率分别为96.6%、96.6%、96.1%、93.2%、92.8%、87.6%和82.8%;而绿僵菌菌株WMS-12、MBD-1对小菜蛾具高毒力,浸后5d试虫的校正死亡率分别为83.3%和69.3%。

In order to screen high virulence fungus strains ,using baiting soil samples with larvae of Galleria mellonella ,thirty‐six soil samples were collected from different ecotype areas in Northeast China .Each soil sample was baited with 30 larvae of third or fourth instar ,fourteen days later ,a total of 454 larvae which had been infected .The occurrence frequency of entomopathogenic fungi in high density area was 80% in Tengjia‐weizi of Kedong county .There were 301 fungus isolated from the cadavers ,most isolates were Beauveriabassi‐ana ,a little Metarrhizium anisopliae and others ,there were 41 fungus isolated ,they were tested under labora‐tory conditions against Myzus persicae and Plutella xylostella .Each isolate was bioassayed under the concen‐trated standard spray of 1 .0 × 10^7 conidia·mL^‐1 .Isolates of JSJ‐10、QG1‐1、MBD‐2、BEE‐15、HYD‐11、MLX‐1 and FN‐9 were more virulent to Myzus persicae ,causing a corrected mortality of 96 .6% 、96 .6% 、96 .1% 、93 .2% 、92 .8% 、87 .6% and 82 .8% after spraying 7 d .As for Plutella xylostella ,isolates of WMS‐12 and MBD‐1 which were Metarrhizium anisopliae were more virulent ,causing a corrected mortality each of 83 .3%and 69 .3% af ter dipping 5 d .