Morphological and molecular identification for four new wood-inhabiting species of Lyomyces (Basidiomycota) from China.

Fungi are one of the most diverse groups of organisms on Earth, in which the wood-inhabiting fungi play an important role in forest ecosystem processes and functions. Four new wood-inhabiting fungi, Lyomyceshengduanensis, L.niveomarginatus, L.wumengshanensis and L.zhaotongensis, are proposed, based on morphological features and molecular evidence. Lyomyceshengduanensis differs in the brittle basidiomata with pruinose hymenial surface, a monomitic hyphal system and ellipsoid basidiospores (3.5-6 × 3-4.5 µm). Lyomycesniveomarginatus is distinguished by the subceraceous basidiomata with crackled hymenial surface, a monomitic hyphal system and ellipsoid basidiospores (4.5-7 × 3-4 µm). Lyomyceswumengshanensis is distinguished by the grandinioid hymenial surface, a monomitic hyphal system and ellipsoid to broad ellipsoid basidiospores (4-6 × 3-5 µm). Lyomyceszhaotongensis is unique in the grandinioid hymenial surface, a monomitic hyphal system and broadly ellipsoid basidiospores measuring as 2.6-3.5 × 2.5-3 µm. Sequences of ITS and nLSU rRNA markers of the studied samples were generated and phylogenetic analyses were performed using the Maximum Likelihood, Maximum Parsimony and Bayesian Inference methods. The phylogram, based on the ITS+nLSU rDNA gene regions, included three genera within the Schizoporaceae viz. Fasciodontia, Lyomyces and Xylodon, in which the four new species were grouped into Lyomyces. The phylogenetic tree inferred from the ITS sequences highlighted that L.hengduanensis group with L.zhaotongensis and then closely grouped with L.crustosus, L.ochraceoalbus, and L.vietnamensis. The new taxon L.niveomarginatus was retrieved as a sister to L.juniperi. The new species L.wumengshanensis was sister to L.macrosporus. The new taxon L.zhaotongensis grouped with L.hengduanensis and then closely grouped with L.crustosus, L.ochraceoalbus and L.vietnamensis.