一株茶大灰象甲寄生真菌的分子鉴定及其毒力测定

摘要

The taxonomic status and biocontrol potential of an entomopathogenic fungus that isolated from the cadaver of Sympiezomias citri were investigated. Amplification, sequencing, and system evolution tree construction of the nuclear ribosomal internal transcribed spacer (rDNA-ITS) and intergenic Bloc region fragments (Bloc) of the fungus Bbr4941, and the bioassay against the adult of S. citri were carried out. The results showed that the entomopathogenic fungus was identified as Beauveria brongniartii. When the adults of S. citri were dealt with Bbr4941 suspension (5.0×107 spore·mL-1), the corrected accumulative mortality was 100％ and LT50 value was 3.916 d after 7 days. Our results showed that Bbr4941 had great potential for the biocontrol of S. citri.%为明确分离自茶大灰象甲(Sympiezomias citri)自然羅病死亡成虫僵虫的一株寄生真菌Bbr4941菌株的具体分类归属及其生防潜力,对该菌株的rDNA-ITS序列和Bloc序列进行了PCR扩增、测序及系统进化树构建.结果明确了它为布氏白僵菌(Beauveria brongniartii).在此基础上,利用浸虫法研究该菌株对茶大灰象甲成虫的室内毒力.结果表明,高浓度(每毫升5.0×107孢子)孢悬液处理时,第7天累计校正死亡率为100％,LT50为3.916 d.以上研究表明Bbr4941菌株对茶大灰象甲成虫具有很强的杀虫毒力,有望在今后茶大灰象甲的生物防治中发挥重要作用.