Introducing Muciflexus inthanonensis gen. et sp. nov. and updates on Ochronectria (Hypocreales): New insights from leaf litter fungi in Doi Inthanon National Park, Northern Thailand

While exploring the leaf litter fungal diversity in Doi Inthanon National Park, Northern Thailand, we discovered a previously unknown lineage within Niessliaceae. Muciflexus inthanonensis gen. et sp. nov. is therefore introduced to accommodate this new lineage. The link between the sexual and asexual morphs of Ochronectria thailandica is also established, while the generic description of Ochronectria is updated.

A polyphasic approach was employed, consisting of multi-locus phylogenetic analysis using ITS, LSU, rpb 2, and tef 1 - α along with the morphological evidence to support the findings. Muciflexus inthanonensis resembles the spore morphology of Phialoseptomonium even though they are phylogenetically distant. Muciflexus inthanonensis forms a sister clade with Trichonectria setadpressa, characterised by a long branch, but differs in asexual morphology, possessing clusters of simple or branched conidiophores compared to the sporodochia-like structure of T. setadpressa.

The discovery of the asexual morph of Ochronectria thailandica from a terrestrial habitat confirms the versatile nature of the fungus, which inhabits both aquatic and terrestrial environments. Here we establish the link between the sexual and asexual morphs of Ochronectria by revealing the holomorphic nature of O. thailandica. This study highlights the diversity of leaf litter fungi and the potential of discovering novel fungal species in northern Thailand.