分离自冬虫夏草可培养真菌的多样性研究

冬虫夏草是生长于青藏高原的一种名贵中药材。天然冬虫夏草及其微环境中生活着多种真菌。作者使用常规分离培养方法对冬虫夏草的真菌区系进行研究。从天然冬虫夏草的子座、菌核和菌膜3个部位共分离到572个真菌菌株,并根据形态特征将大部分菌株鉴定到37个不同的属。这些菌株经SSCP(single-strand conformation polymorphism)分析后,再根据nrDNAITS序列的相似性(以97%为阈值)共区分出92种不同的分类单元(operational taxonomic unit,OTU)。其中,属于子囊菌的菌株数及OTU数均比接合菌和担子菌多。从菌膜分离的菌株数及OTU数都明显多于子座和菌核。分离自子座的优势真菌是产黄青霉Penicillium chrysogenum,而分离自菌核和菌膜的优势真菌均为玫红假裸囊菌Pseudogymnoascus roseus。尚未最终鉴定的部分真菌可能为新的真菌物种。

Mycobiotal investigation of natural Ophiocordyceps sinensis based on culture-dependent investigation

Natural Ophiocordyceps sinensis, a traditional Chinese medicine, is endemic to alpine regions on the Tibetan Plateau. Various fungal species have been reported to be associated with natural O. sinensis. In this study, the mycobiota of natural O. sinensis was investigated with the traditional culture-dependent method. In total, 572 fungal cultures were isolated from different parts (stromata, sclerotia, and external mycelial cortices) of natural O. sinensis. Most of these cultures were assigned to 37 genera according to morphological characteristics, and 92 OTUs were identified at the 97% similarity threshold according to their nrDNA ITS sequences following SSCP analyses. The number of isolates and OTUs of Ascomycetes was larger than that of Basidiomycetes and Zygomycetes. More isolates and OTUs were obtained from cortices than from sclerotia and stromata. The most abundant species from stromata was Penicillium chrysogenum, while that from both sclerotia and cortices was Pseudogymnoascus roseus. Several unclassifiable fungal species were also detected in this study, which could be novel species.