Taxonomy and Phylogeny Reveal Two New Potential Edible Ectomycorrhizal Mushrooms of Thelephora from East Asia

Abstract

The ectomycorrhizal basidiomycetes genus Thelephora has been understudied in subtropical ecosystems. Many species of Thelephora are important edible and medicinal fungi, with substantial economic value. Two new Thelephora species, T. grandinioides and T. wuliangshanensis spp. nov. are proposed here based on a combination of morphological features and molecular evidence. Thelephora grandinioides is characterized by laterally stipitate basidiocarps with a grandinoid hymenial surface, a monomitic hyphal system with clamped generative hyphae, and the presence of tubular and septated cystidia and subglobose to globose basidiospores measuring as 5.3–7.4 × 4–6.5 µm. Thelephora wuliangshanensis is characterized by infundibuliform basidiocarps, radially black striate on the pileus, a smooth, umber to coffee hymenial surface, a monomitic hyphal system with thick-walled generative hyphae, and basidiospores that turn greenish grey to buff in 5% KOH. Phylogenetic analyses of rDNA internal transcribed spacer region (ITS) and nuclear large subunit region (nrLSU) showed that the two new Thelephora are phylogenetically distinct: T. grandinioides is sister to T. aurantiotincta and T. sikkimensis, while T. wuliangshanensis is sister to a clade comprising T. austrosinensis and T. aurantiotincta with high support as well.