眩灯蛾白僵菌菌株(两株)的分离、鉴定及其对棉蚜致病力试验

Isolation and identification of two strains of Beauveria sp.and its biological activity to Aphis gossypii

从新疆北部沙漠边缘植物梭梭Haloxylon ammodendron上自然感染死亡的眩灯蛾Lacydes spectabilis(Tauscher)上分离出两株白僵菌,经形态学和分子生物学方法鉴定为球孢白僵菌Beauveria bassiana。采用浸虫法测定分离白僵菌CXJ-1和CXJ-2菌株在不同浓度下对棉蚜的室内致病力,试验结果表明白僵菌CXJ-1和CXJ-2两菌株在浓度为4.75×109个/mL浓度下对棉蚜累计校正死亡率分别达到94.76%和94.33%,致死中浓度分别为4.37×105个/mL和1.08×106个/mL,致死中时间分别为3.54d和3.59d。分离获得的两株球孢白僵菌对棉蚜均具有较好的致病力,其中菌株CXJ-1致病力比CXJ-2高。

Two Beauveria had been isolated from dead Lacydes spectabilis samples that been collected from northern desert of Xinjiang Province. Two isolates were identified as Beauveria bassiana by morphological characteristics and the method of molecular biology. The virulence of five different concentrations of isolates of Beauveria bassiana named CXJ - 1 and CXJ -2 against Aphis gossypii was tested by using insect dip bio- assay in laboratory. The result showed that the corrected accumulative mortality of Aphis gossypii were 94. 76%, 94. 33%, LC50 were 4. 37 × 105 spores/mL, 1.0s × 106 spores/mL, LTs0were 3. 54 d, 3. 59d respectively, under the concentration of 4. 75 x l09 spores/mL. The result of the experiment showed that two strains had better con- troling effect to A. gossypii, the strain of CXJ - 1 had better controling effect than A. gossypii.