土壤中棒束孢菌的生物多样性及对黄曲条跳甲的活性

目的 调查国内部分地区不同土壤中棒束孢属Isaria真菌的多样性分布，测定其对黄曲条跳甲Phyllotreta striolata的生物活性，促进棒束孢菌对黄曲条跳甲的生防应用。方法 从福建、广东、广西、云南、贵州、湖南、湖北、河南、河北等地的不同生境中采集土壤样品，通过选择培养基分离纯化棒束孢菌株，根据形态学和分子标记鉴定菌种，采用多样性指数与优势度指数评价生物多样性；采用浸虫法测定棒束孢菌株对黄曲条跳甲成虫的生物活性。结果 从200余份土壤样品中分离得到棒束孢属真菌41株，优势菌种是爪哇棒束孢Isaria javanica，有34株，优势度指数为0.829；玫烟色棒束孢I. fumosorosea有5株，粉棒束孢I. farinosa和环链棒束孢I. cateniannulate各1株。林地物种丰富度最高，多样性指数为1.121，休耕地、果园、耕地和草地的多样性指数范围为0~0.349；林地种间分配最均匀，优势度指数为0.468，休耕地、果园、耕地和草地的优势度指数范围为0~0.159。生测结果表明，大部分供试的棒束孢菌株对黄曲条跳甲都有一定活性，玫烟色棒束孢IfH6102菌株对黄曲条跳甲的活性最高，在处理黄曲条跳甲成虫11 d后，其校正死亡率达60.89%。结论 棒束孢菌在我国土壤中分布广泛，林地生境中的物种多样性最丰富，棒束孢菌具有防治黄曲条跳甲的应用潜力。

Biodiversity of Isaria in soil and its activity against Phyllotreta striolata

Objective To investigate the diversity of Isaria from different soils in some areas of China, and to determine their bioactivity against Phyllotreta striolata, so as to promote the application of Isaria as biocontrol agents.Method Soil samples were collected from different habitats in Fujian, Guangdong, Yunnan, Guizhou, Hunan, Hubei, Henan, Hebei and Guangxi Provinces (Regions). Isaria strains were isolated and purified by selective medium, and identified based on morphology and molecular markers. The Shannon-Weiner and dominance indexes were used to evaluate the biodiversity. The biological activities of Isaria strains against P. striolata were determined by immersion method.Result A tatol of 41 Isaria strains were isolated from more than 200 soil samples. The dominant species was I. javanica with 34 strains and a dominance index of 0.829. Meanwhile, five strains of I. fumosorosea, one strain of I. farinosa and one strain of I. cateniannulate were isolated. The woodland habitat had the highest biodiversity for Isaria with Shannon-Wiener index of 1.121, followed by fallow land, orchard, farmland, grassland with the Shannon-Wiener indexes ranged from 0 to 0.349. Woodland habitat had the most uniform distribution among species, with the dominance index of 0.468, and the dominance indexes of fallow land, orchard, farmland and grassland ranged from 0 to 0.159. The results of bioassay showed that most tested strains had certain activity against P. striolata. The strain IfH6102 had the highest activity with the corrected mortality of 60.89% at 11 days after treatment.Conclusion Isaria is widely distributed in the soil of China. The woodland has the highest biodiversity for Isaria, and Isaria has the potential to be used for controlling P. striolata.