Ophiocordyceps megala sp. nov (Ophiocordycepitaceae) enriches the species diversity of the O. sinensis-affined lineage

Abstract

Abstract Ophiocordyceps is a species-rich genus in the order Hypocreales (Ascomycota) including large numbers of invertebrate-pathogen. Ophiocordyceps sinensis is a famous traditional Chinese medicine that adapts to the alpine environment in the Qinghai-Tibet Plateau and adjacent region. The diversity of Ophiocordyceps sinensis affined species could expand the traditional medicinal resources and provide insight to the adaptation to different ecological environments. In this study, a new species O. megala was reported from the Hengduan Mountains, one of biodiversity hotspot area. O. megala differed considerably from related species mainly in having massive stromata, long phialides, single big conidia and the huge-sized host. Phylogenetic analyses based on five genes of nrSSU, nrLSU, tef, rpb1 and rpb2 clarified that O. megala was in the O. sinensis Clade and closed to O. sinensis. The combined morphological, ecological and phylogenetic evidences supported its distinctiveness from allied O. sinensis, O. xuefengensis and O. macroacicularis. Meanwhile, the prediction of the suitable distribution of seven O. sinensis -affined species revealed that their potential suitable distribution extends from the southeastern QTP to the Xuefeng mountains with non-sporadically fragmented regions. The specific biodiversity corridor hypothesis was put forward in this paper, i.e., the O. sinensis-affined species might have an entire suitable distribution area from west to east, which could provide an excellent ecological environment for the spread and evolution of this unique group. Our results should have positive significance for the diversity and adaptive evolution of the O. sinensis-affined phylogenetic lineage.