Phylogeny and Taxonomy of the Naematelia aurantialba Complex in Southwestern China

<i>Naematelia aurantialba</i> and its allies are important edible and medicinal mushrooms in China. They are usually called Jiner () and have been cultivated on a commercial scale. However, due to the lack of DNA sequences from the holotype of <i>Naematelia aurantialba</i>, the taxonomic issues of the species complex are unresolved. In this study, the authors successfully generated DNA sequences from the holotype of <i>N. aurantialba</i> by a genome skimming approach and additional allied species by Sanger sequencing. Based on morphological characteristics, molecular phylogenetic data, and geographic distribution patterns, four species, including three new ones, in the complex in southwestern China were uncovered. <i>Naematelia aurantialba</i> occurs at high altitudes (over 3000 m above sea level), with subalpine dead plants as its substrates, and has larger basidiospores, while the commonly cultivated species, described as <i>N. sinensis</i> in this work, is distributed in subtropical areas at altitudes between 1800 m and 2600 m on the dead wood of subtropical plants and has smaller basidiospores. The third species, namely <i>N. nodulosa</i>, has habitats similar to those of <i>N. sinensis</i> but differs from the latter in its basidiomata with an uneven nodulose surface, a loose context with small internal cavities, and numerous conidia. The fourth species, <i>N. pedicellata</i>, is easily distinguished from the others by its basidia, with long basal stalks and broadly ellipsoid basidiospores measuring 10.5-12.5 × 8.0-10.0 μm. All these species are parasitic on <i>Stereum</i> species. This study provides a solid basis for future guidance for the selection of new strains and cultivation practices of these valuable fungi.