﻿Redelimitation of Heteroradulum (Auriculariales, Basidiomycota) with H.australiense sp. nov.

Qian-Zhu Li,Li-Wei Zhou,Tom W May,Shi-Liang Liu,Xue-Wei Wang

doi:10.3897/mycokeys.86.76425

Abstract

Auriculariales accommodates species with diverse basidiomes and hymenophores. From morphological and phylogenetic perspectives, we perform a taxonomic study on Heteroradulum, a recently validated genus within the Auriculariales. The genus Grammatus is merged into Heteroradulum, and thus its generic type G.labyrinthinus is combined with Heteroradulum and G.semis is reaccepted as a member of Heteroradulum. Heteroradulumaustraliense is newly described on the basis of three Australian specimens. Heteroradulumyunnanense is excluded from this genus and its taxonomic position at the generic level is considered uncertain. Accordingly, the circumscription of Heteroradulum is re-delimited and the concept of this genus is adjusted by including irpicoid to poroid hymenophores and a hyphal system with clamp connections or simple septa. A key to all nine accepted species of Heteroradulum is presented.

Highlights

Auriculariales (Agaricomycetes, Basidiomycota) is characterized by a wood-inhabiting habit and longitudinally or transversely septate basidia (Weiß and Oberwinkler 2001)
The Maximum Likelihood (ML) and Bayesian Inference (BI) analyses generated similar topologies in main lineages, and the topology generated from ML analysis is presented along with BS values above 50% and Bayesian posterior probabilities (BPPs) above 0.8 at the nodes (Figure 1)
The three newly sequenced Australian specimens grouped as a fully supported lineage, as sister to the two species formerly placed in the genus Grammatus, forming a strongly supported subclade (BS = 92%, BPP = 1), while the monophyly of the subclade including the remaining species of Heteroradulum, viz. H. adnatum Spirin & Malysheva, H. deglubens (Berk. & Broome) Spirin & Malysheva and H. kmetii, did not receive reliable statistical support (Figure 1)

Summary

Introduction

Auriculariales (Agaricomycetes, Basidiomycota) is characterized by a wood-inhabiting habit and longitudinally or transversely septate basidia (Weiß and Oberwinkler 2001). The diverse macromorphological characters result in the taxonomy of Auriculariales having rarely focused on the whole order. The redefined Auriculariales was composed of five well supported groups, but the monophyly of this order even as represented by limited samples was not statistically supported (Weiß and Oberwinkler 2001). With this phylogenetic frame as a main reference, the taxonomy and phylogeny of poroid and lamellate species were further explored (Miettinen et al 2012; Zhou and Dai 2013; Sotome et al 2014; Wu et al 2017; Spirin et al 2019a). The knowledge of the diversity of species with gelatinous basidiomes has been extremely enriched recently (Bandara et al 2015; Wu et al 2015a, b; Malysheva et al 2018; Spirin et al 2018, 2019b; Chen et al 2020; Ye et al 2020; Wang and Thorn 2021)

Methods

Results

Conclusion