榆紫叶甲病原菌分离及生防菌的筛选与鉴定

目的]探寻防治榆紫叶甲病的生防菌株。方法]从榆紫叶甲虫体上分离菌株后进行培养,并对室内饲养的榆紫叶甲各龄幼虫进行致病性试验。结果]从感病榆紫叶甲成虫虫体上分离到18个菌株,其中12个菌株具有几丁质和蛋白质降解活性。5个菌株对1~2龄幼虫表现出不同程度的致病力,在接种后1~3 d幼虫开始死亡,处理后7 d幼虫的累积死亡率为21.2%~46.8%,其中YJA-03和YJA-10菌株的累积死亡率30.0%。YJA-03菌株为革兰氏阳性菌,经过形态学、生理生化特性和PCR扩增鉴定确定它属于短杆菌属(Exiguobacterium)。YJA-10菌株为革兰氏阴性菌,经鉴定其属于Glutamicibacter属。结论]YJA-03和YJA-10菌株可用作防治榆紫叶甲病的生防菌。

Isolation,Screening and Identification of Bacterial Agents for Biological Control of Ambrostoma quadriimpressum

Objective] To explore the pathogen for the biological control of Ambrostoma quadriimpressum.Method] Some bacteria strains were isolated from A.quadriimpressum to determine the pathogenicity of Bacillus thuringinensis to each instrar of larvae fed in the laboratory.Result] 18 bacterial isolates were obtained from diseased adults of A.quadriimpressum,among them 12 isolates showed protein-degrading and chitin-degrading activities.5 isolates showed different pathogenicity to 1st-instar and 2nd-instar larvae of A.quadriimpressum.The larvae began to die during 3-7 d after inoculation,and the accumulative mortality rate of larvae of A.quadriimpressum was 21.2%-46.8%.The accumulative mortality rate of A.quadriimpressum larvae to YJA-03 strain and YJA-10 strain were more than 30%.YJA-03 was identified as Gram-positive bacterium,a bacteria of genus Exiguobacterium identified by morphological,physiological and biochemical characteristics and PCR amplification.YJA-10 was identified as Gram-negative bacterium,belonging to genus Glutamicibacter.Conclusion] YJA-03 strain and YJA-10 strain can be used for the biological control of A.quadriimpressum.