Multi-Gene Phylogeny and Taxonomy of Hydnellum (Bankeraceae, Basidiomycota) from China.

Yan-Hong Mu,Hai-Sheng Yuan,Xiang-Hua Wang,Ting Cao,Jia-Rui Yu

doi:10.3390/jof7100818

Abstract

The genus Hydnellum is an important group of stipitate hydnaceous fungi which can form ectomycorrhiza with many species of woody plants. In recent decades, the frequency and number of basidiocarps observed in China have been declining significantly. So far, however, we know little about the species diversity of Hydnellum in China. In this study, we conducted molecular phylogenetic analyses based on sections of multiple loci, including the large subunit of nuclear ribosomal RNA gene (nLSU), the internal transcribed spacer regions (ITS), the small subunit of nuclear ribosomal RNA gene (SSU) and the second-largest subunit of RNA polymerase II gene (RPB2), as well as morphological studies, of collected samples of Hydnellum from China. We also inferred Maximum Likelihood and Bayesian phylogenies for the order Thelephorales from the dataset of the combined nLSU and ITS. This study has revealed the phylogenetic position of Hydnellum in the order Thelephorales, and phylogenetically confirmed ten major clades in Thelephorales; Twenty-nine taxa are proposed, described or reported, including 10 new subgenera (Hydnellum subgenus Hydnellum, subg. Caesispinosum, subg. Croceum, subg. Inflatum, subg. Rhizomorphum, subg. Scabrosum, subg. Spongiosum, subg. Subindufibulatum, subg. Violaceum and subg. Zonatum), 11 new species (Hydnellum atrorubrum, H. atrospinosum, H. bomiense, H. brunneorubrum, H. fibulatum, H. granulosum, H. inflatum, H. rubidofuscum, H. squamulosum, H. sulcatum and H. yunnanense), 3 newly recorded species (H. caeruleum, H. peckii and H. spongiosipes) and 5 notable specimens (Hydnellum sp 1, H. sp 2, H. sp 3, H. sp 4 and H. sp 5). A classification system based on the morphological characteristics (especially the hyphal structure types) and molecular analyses is proposed to accommodate most species in Hydnellum. The distinguishing characters of the subgenera and the new species with their closely related taxa are discussed. A key to the species of Hydnellum from China is provided.

Highlights

The genus Hydnellum, together with Bankera, Phellodon and Sarcodon, are a homogenous group of soil-inhabiting Basidiomycota that belongs to the Bankeraceae, Thelephorales [1,2].All species of Bankeraceae are considered ectomycorrhizal and are associated with woody plants, mainly members of Pinaceae and Fagaceae [3,4,5,6,7], and colonize natural or relatively undisturbed forests [8]
The phylogenetic construction performed with maximum likelihood and Bayesian Inference (BI) analyses for two combined datasets showed similar topology
Phylogenetic analyses using four loci of Hydnellum and Sarcodon were carried out using sequences from Europe, Asia and America

Summary

Introduction

All species of Bankeraceae are considered ectomycorrhizal and are associated with woody plants, mainly members of Pinaceae and Fagaceae [3,4,5,6,7], and colonize natural or relatively undisturbed forests [8]. These fungi can absorb organic substances from host plants and transport nutrients and water from the soil to the plants, which improves the stability of forest ecosystems [9,10]. This can be on par with the health benefit potentials of herbal plant infusions [13]

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