Fungal Diversity In The Community Of Naturally-occurring Ophiocordyceps Sinensis

Natural Ophiocordyceps sinensis is the results of parasitism of O. sinensis on underground ghost moth larvae on the Tibetan Plateau. The anamorph of O. sinensis has been widely recognized as Hirsutella sinensis. There are still, however, a lot of other fungi on natural O. sinensis that are important fungal resources. Several of these fungi have been found to have similar chemical components and pharmacological activities to O. sinensis, and fermented mycelial products have been developed and applied in clinical practice. These fungi are hypothesized to involve in the process of natural O. sinensis formation. Therefore, it is necessary to conduct a comprehensive investigation on the fungal diversity on natural O. sinensis.Until now, the mycobiota of nature O. sinensis specimens has not been investigated in detail. In this study, the traditional culture-dependent method and the culture-independent (ITS clone library) method were used to detect the mycobiota of different sections (stromata, sclerotia, and mycelial cortices) natural O. sinensis originating from different geographical localities. The fungal community structures and their abundance were analyzed by morphological and molecular characteristics. We prepared to infer the total fungal species of the same part of O. sinensis from different regions through a comparative analysis, to lay the foundation for the further study of the relationship between the mycobiota and O. sinensis in the process of O. sinensis formation. The study also expects to provide guidance for edibility and protection of O. sinensis and to further enrich medicinal fungal resources in China.In this study, the O. sinensis samples were collected from Deqin in Yunnan province, Markam in Tibet, Longzi in Tibet, and Mozhugongka in Tibet. A total of3192strains/clones (including485fungal isolates from culture-dependent investigations and2707positive clones from culture-independent investigations) were analyzed by two methods. After the SSCP (single-strand conformation polymorphism) analysis for all stains/clones,453strains/clones were selected to be sequenced, and141OTUs (Operational taxonomic unit) were identified at the97%similarity threshold by DNAMAN homologous tree analysis (excluding plants and animals). These OTUs include94ascomycetes,25basidiomycetes,13zygomycetes, and9others. The O. sinensis (71%), Geomyces vinaceus (5%), and Penicillium swiecickii (4%) were the dominant species. There were47OTUs being detected in the Deqin sample according to123fungal isolates and670positive clones. There were60OTUs being detected in the Mangkang sample according to158fungal isolates and710positive clones. There were44OTUs being detected in the Longzi sample according to108fungal isolates and683positive clones. There were43OTUs being detected in the Mozhugongka sample according to96fungal isolates and644positive clones. The Tibet Mangkang sample was the highest at diversity index than other samples. The Tibet Longzi sample was the most similar with the Mozhugongka sample among all samples (Cs=0.3)...