东亚飞蝗肠道细菌鉴定及其对金龟子绿僵菌拮抗作用分析

通过对室内饲养的东亚飞蝗5龄若虫肠道细菌的分离纯化培养,共获得8个细菌菌株,16s rDNA鉴定分别与绿脓杆菌(Pseudomonas aeruginosa)、克雷伯氏菌属(Klebsiellasp.)、地衣芽孢杆菌(Bacillus licheniformis)、阴沟肠杆菌(Enterobacter cloacae)、节杆菌属(Arthrobactersp.)、木糖葡萄球菌(Staphylococcus xylosus)、蜡状芽孢杆菌(Bacillus cereus)和芽孢杆菌属(Bacillussp.)有较高的同源性,其中克雷伯氏菌和阴沟肠杆菌检出率为100%,检出量最大,均达到109cfu/g肠道,为常驻的优势菌群。肠道细菌在东亚飞蝗体内的数量分布为后肠>中肠>前肠,种类分布为中肠(8种)>后肠(6种)>前肠(4种)。常驻细菌克雷伯氏菌和阴沟肠杆菌对金龟子绿僵菌则无拮抗作用,表明肠道常驻菌不是影响金龟子绿僵菌在蝗虫肠道内萌发侵染的主要因素,但同时也说明了在不同环境条件下使用绿僵菌防治蝗虫在防效上可能会有很大的差异。

Identification of the intestinal bacteria in Locusta migratoria manilensis and their antagonism to Metarhizium anisopliae

Eight bacteria strains were isolated from the intestines of Locusta migratoria manilensis through a series of experiments.The results based on 16s rDNA sequence analysis indicated that the eight bacterial strains had high homology with Pseudomonas aeruginosa,Klebsiella sp.,Bacillus licheniformis,Enterobacter cloacae,Arthrobacter sp.,Staphylococcus xylosus,Bacillus cereus and Bacillus sp.respectively.The detection rate of Klebsiella sp.and E.cloacae was 100%,which were considered as the predominant and indigenous flora.The numbers of bacterial strains appeared in the order of hindgut>midgut>foregut,but the strains distributed in the order of midgut(8)>hindgut(6)>foregut(4).The antagonism assay indicated that P.aeruginosa,B.cereus and Bacillus sp.had obvious antagonism to Metarhizium anisopliae,and B.licheniformis and Arthrobacter sp.had weak antagonism,while Klebsiella sp.,E.cloacae and S.xylosus had no effects.It is therefore concluded that the bacteria in the gut of L.migratoria manilensis are not the definitive factor inhibiting the germination of M.anisopliae.Whether or not M.anisopliae can affect L.migratoria manilensis through the intestines needs further studies in the future.