广义虫草属二新记录种

Two new recorded species in Cordyceps sensu lato

摘要:

【背景】广义虫草属是一类重要的虫生真菌资源。【目的】对我国西南地区虫生真菌及其相关真菌资源进行调查。【方法】在贵州省习水县和花溪区进行标本采集，采用含双抗的PDA培养基分离目的菌株；基于形态学特征和ITS rDNA序列系统发育分析相结合的方法进行菌株鉴定。【结果】从采集到的标本中分离获得5个菌株，菌株GY1113、GY90809和GY90810在形态特征上与马拉维白僵菌模式菌株非常相近；系统发育树中二者以高持率(ML/BI为99/1)聚成一个分支。菌株A1997在形态特征上与鳞翅目虫草模式菌株非常吻合；系统发育树中二者以较高支持率(ML/BI为78/0.95)聚成一个分支。菌株A1972在形态上与苏格兰白僵菌模式菌株的形态特征非常相近；系统发育树中二者以高支持率(ML/BI为99/1)聚成一个分支。因此分别鉴定为马拉维白僵菌、鳞翅目虫草及苏格兰白僵菌。【结论】马拉维白僵菌和鳞翅目虫草为中国新记录种。

Abstract:

[Background] Cordyceps sensu lato was an important entomopathogenic fungus. [Objective] The entomopathogenic fungi and its allies from Southwest China were investigated. [Methods] Specimens were collected from Xishui and Huaxi in Guizhou province, and the target strains were isolated on PDA media with antibiotics in the laboratory. Then these strains were identified by the morphological characters and phylogenetic analysis of ITS rDNA sequences. [Results] Five target strains were obtained. Strains GY1113, GY90809 and GY90810 were very similar to the original description of Beauveria malawiensis in morphology and clustered into a subclade with the sequences of B. malawiensis in phylogenetic tree; strain A1997 was consistent with Cordyceps lepidopterorum in morphology and it was closely related with the type sequence of C. lepidopterorum in phylogenetic tree; strain A1972 was very similar to the original description of B. caledonica in the morphology and clustered into a subclade with the sequences of B. caledonica in phylogenetic tree. Therefore, these strains were identified to three species, B. malawiensis, C. lepidopterorum and B. caledonica, respectively. [Conclusion] B. malawiensis and C. lepidopterorum are new to China.