Systematic revision of Hydnum species in Japan

ABSTRACT

Hydnum (Hydnaceae, Basidiomycota) exhibits endemic species diversity in East Asia; however, few comprehensive systematic studies have been conducted to date. Here, we performed morphological, ecological, phylogenetic, and biological evaluations of the taxonomy of Hydnum species in Japan. In total, 186 Japanese Hydnum specimens were used for morphological observations. Phylogenetic trees were constructed using sequence data of nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) region and a portion of translation elongation factor 1-α (tef1). Intra- and interspecific mating tests using 78 monokaryotic strains of 13 species did not conflict with species delimitation inferred from their ITS and tef1 phylogenetic relationships. This study provides detailed morphological descriptions of 15 rigorously identified species from Japan, nine of which are described as new: H. alboluteum, H. albopallidum, H. pinicola, H. itachiharitake, H. minospororufescens, H. orientalbidum, H. subberkeleyanum, H. tomaense, and H. tottoriense. Three species documented in this work are new to Japan: H. boreorepandum, H. mulsicolor, and H. umbilicatum. The remaining three species (H. cremeoalbum, H. minus, and H. repando-orientale), previously reported from Japan, are redescribed using data from newly collected materials. We also transferred two old species (Hericium fimbrillatum and Sarcodon nauseofoetidus) from East Asian Hydnum into other genera.

KEYWORDS:

• Cantharellales
• cryptic species
• doubtful species
• East Asian species
• ectomycorrhizal fungi
• ITS
• mating test
• tef1
• 11 new taxa

Supplemental data

Supplemental data for this article can be accessed on the publisher’s Web site.

ACKNOWLEDGMENTS

We thank Dr. K. Hosaka (Department of Botany, Division of Fungi and Algae, National Museum of Nature and Science, Tokyo) and Dr. I. Salcedo (BIO Herbarium, Faculty of Science and Technology, University of the Basque Country [UPV/EHU]) for loans from their herbarium collections; the Nagano Prefectural Government, the Ministry of the Environment, and the Forestry Agency of Japan for the permissions of field research in special protection zone; and Dr. S. Ushijima (The Tottori Mycological Institute) and Dr. A. Yamada (Department of Bioscience and Biotechnology, Faculty of Agriculture, Shinshu University, Japan) for providing field sampling opportunities. We also thank W. Aoki, M. Furukawa, S. Habu, A. Hosono, A. Iwama, H. Shirayama, and S. Tagami for providing field collection samples, and the staff of the Division of Instrumental Research, Research Center for Supports to Advanced Science, Shinshu University, for technical support regarding DNA sequencing.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by JSPS KAKENHI Grant Number JP20J20884 (Ryo Sugawara) from Japan Society for the Promotion of Science, by research grant from the Institute for Fermentation, Osaka (to Naoki Endo), and by a research fund from the president of Tottori University.