Morphological and phylogenetic analyses revealed Fissuracium ellipsoideum gen. et sp. nov. (Amylocorticiaceae, Amylocorticiales) from southwest China

Wood-inhabiting fungi play a fundamental role in ecosystem processes, particularly in wood degradation and the recycling of organic matter. In the present study, a new wood-inhabiting fungal genus Fissuracium, with its type species, F. ellipsoideum sp. nov., found in southwest China, is proposed based on a combination of morphological features and molecular evidence. The genus Fissuracium is characterized by the resupinate basidiomata with a cracking hymenophore, a monomitic hyphal system with clamped generative hyphae, the presence of cystidioles, and ellipsoid, thick-walled basidiospores.

Sequences of the internal transcribed spacers (ITS), nuclear large subunit ribosomal RNA (nLSU), RNA polymerase second largest subunit (rpb 2) and translation elongation factor 1 - α (tef 1 - α) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated. Phylogenetic analyses were performed using Maximum Likelihood, Maximum Parsimony, and Bayesian Inference. Multi-locus phylogenetic analyses of ITS + nLSU + rpb 2 + tef 1 - α showed that Fissuracium forms a monophyletic clade within the family Amylocorticiaceae, which was clustered into the order Amylocorticiales.

The phylogenetic analyses indicated that the new genus Fissuracium formed a single lineage. A full description, illustrations, and phylogenetic analyses results of the new taxa are provided.