IMA Fungus 12(1): e33943, doi: 10.1186/s43008-021-00064-0
Enlightening the black and white: species delimitation and UNITE species hypothesis testing in the Russula albonigra species complex
Ruben De Lange, Slavomir Adamcik‡, Katarína Adamčíková, Pieter Asselman, Jan Borovička§, Lynn Delgat, Felix Hampe|, Annemieke Verbeken¶‡ Slovak Academy of Sciences, Bratislava, Slovakia§ Institute of Geology of the Czech Academy of Sciences, Prague 6, Czech Republic| Ghent University, Research Group Mycology, Department of Biology, Ghent, Belgium¶ Ghent University, Ghent, Belgium
© Ruben De Lange, Slavomir Adamcik, Katarína Adamčíková, Pieter Asselman, Jan Borovička, Lynn Delgat, Felix Hampe, Annemieke Verbeken. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY-NC 4.0), which permits to copy and distribute the article for non-commercial purposes, provided that the article is not altered or modified and the original author and source are credited. Citation:
De Lange R, Adamcik S, Adamčíková K, Asselman P, Borovička J, Delgat L, Hampe F, Verbeken A (2021) Enlightening the black and white: species delimitation and UNITE species hypothesis testing in the Russula albonigra species complex. IMA Fungus 12(1): e33943. https://doi.org/10.1186/s43008-021-00064-0 |  |
Abstract
Russula albonigra is considered a well-known species, morphologically delimited by the context of the basidiomata blackening without intermediate reddening, and the menthol-cooling taste of the lamellae. It is supposed to have a broad ecological range and a large distribution area. A thorough molecular analysis based on four nuclear markers (ITS, LSU, RPB2 and TEF1-α) shows this traditional concept of R. albonigra s. lat. represents a species complex consisting of at least five European, three North American, and one Chinese species. Morphological study shows traditional characters used to delimit R. albonigra are not always reliable. Therefore, a new delimitation of the R. albonigra complex is proposed and a key to the described European species of R. subgen. Compactae is presented. A lectotype and an epitype are designated for R. albonigra and three new European species are described: R. ambusta, R. nigrifacta, and R. ustulata. Different thresholds of UNITE species hypotheses were tested against the taxonomic data. The distance threshold of 0.5% gives a perfect match to the phylogenetically defined species within the R. albonigra complex. Publicly available sequence data can contribute to species delimitation and increase our knowledge on ecology and distribution, but the pitfalls are short and low quality sequences.
Keywords
Basidiomycota, Coalescent species delimitation, Ectomycorrhizal fungi, New species, Phylogeny, Russulaceae, Russulales, Russula subgen. Compactae, Integrative taxonomy, Typification, New taxa