Taxonomic novelties and global biogeography of Montagnula (Ascomycota, Didymosphaeriaceae)

Whilst conducting surveys of lignicolous microfungi in Yunnan Province, we collected a large number of taxa that resemble Montagnula (Didymosphaeriaceae, Pleosporales). Our phylogenetic study on Montagnula involved analysing sequence data from ribosomal RNA genes (nc18S, nc28S, ITS) and protein-coding genes (rpb2, tef1-α). We present a biphasic approach (morphological and molecular phylogenetic evidence) that supports the recognition of four new species in Montagnula viz., M. lijiangensis, M. menglaensis, M. shangrilana and M. thevetiae. The global diversity of Montagnula is also inferred from metabarcoding data and published records based on field observations. Metabarcoding data from GlobalFungi and field observations provided insights into the global diversity and distribution patterns of Montagnula. Studies conducted in Asia, Australia, Europe, and North America revealed a concentration of Montagnula species, suggesting regional variations in ecological preferences and distribution. Montagnula species were found on various substrates, with sediments yielding a high number of sequences. Poaceae emerged as a significant contributor, indicating a potential association between Montagnula species and grasses. Culture-based investigations from previously published data revealed Montagnula species associations with 105 plant genera (in 45 plant families), across 55 countries, highlighting their wide ecological range and adaptability. This study enhances our understanding of the taxonomy, distribution, and ecological preferences of Montagnula species. It emphasizes their role in the decomposition of organic matter in grasslands and savannah systems and suggests further investigation into their functional roles in ecosystem processes. The global distribution patterns and ecological interactions of Montagnula species underscore the need for continued research and conservation efforts.