A new genus and two new species of Auriculariales (Basidiomycota) from southwest China, evidenced by morphological characteristics and phylogenetic analyses

Abstract Wood-inhabiting fungi, a remarkably diverse group morphologically, phylogenetically, and ecologically, play a fundamental role in ecosystem processes, particularly in wood degradation and the recycling of organic matter. Recognized as pivotal contributors to the intricate balance of forest ecosystems, these fungi are renowned as “key players” due to their enzymatic prowess, effectively breaking down woody components like lignin, cellulose, and hemicellulose. In the present study, a new wood-inhabiting fungal genus Nodulochaete, and two new species N. fissurata and N. punctata, collected from southwest China, are proposed based on a combination of morphological features and molecular evidence. The new genus Nodulochaete is characterized by the resupinate basidiomata with smooth to tuberculate hymenophore, a dimitic hyphal system with clamped generative hyphae, presence of abundantly nodulose hyphidia, ellipsoid to ovoid, longitudinally septate basidia, and cylindrical to allantoid basidiospores. Sequences of the internal transcribed spacers (ITS) and the large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated. Phylogenetic analyses were performed with Maximum Likelihood, Maximum Parsimony and Bayesian Inference methods. Phylogenetic analyses of ITS + nrLSU nuclear RNA gene regions show that Nodulochaete forms a monophyletic lineage within the order Auriculariales. Furthermore, two new species N. fissurata and N. punctata were assigned to the genus Nodulochaete.