Tremella rhizocarpicola sp. nov. and other interesting lichenicolous Tremellales and Filobasidiales in the Nordic countries

To explore strange new worlds - The diversification in Tremella caloplacae was linked to the adaptive radiation of the Teloschistaceae

Lichenicolous fungi are a heterogeneous group of organisms that grow exclusively on lichens, forming obligate associations with them. It has often been assumed that cospeciation has occurred between lichens and lichenicolous fungi, but this has been seldom analysed from a macroevolutionary perspective. Many lichenicolous species are rare or are rarely observed, which results in frequent and large gaps in the knowledge of the diversity of many groups. This, in turn, hampers evolutionary studies that necessarily are based on a reasonable knowledge of this diversity. Tremella caloplacae is a heterobasidiomycete growing on various hosts from the lichen-forming family Teloschistaceae, and evidence suggests that it may represent a species complex. We combine an exhaustive sampling with molecular and ecological data to study species delimitation, cophylogenetic events and temporal concordance of this association. Tremella caloplacae is here shown to include at least six distinct host-specific lineages (=putative species). Host switch is the dominant and most plausible event influencing diversification and explaining the coupled evolutionary history in this system, although cospeciation cannot be discarded. Speciation in T. caloplacae would therefore have occurred coinciding with the rapid diversification - by an adaptive radiation starting in the late Cretaceous - of their hosts. New species in T. caloplacae would have developed as a result of specialization on diversifying lichen hosts that suddenly offered abundant new ecological niches to explore or adapt to.

Four new species in the Tremellafibulifera complex (Tremellales, Basidiomycota)

Samples of species close to Tremellafibulifera from China and Brazil are studied, and T.fibulifera is confirmed as a species complex including nine species. Five known species (T.cheejenii, T.fibulifera s.s., T. “neofibulifera”, T.lloydiae-candidae and T.olens) and four new species (T.australe, T.guangxiensis, T.latispora and T.subfibulifera) in the complex are recognized based on morphological characteristics, molecular evidence, and geographic distribution. Sequences of eight species of the complex were included in the phylogenetic analyses because T.olens lacks molecular data. The phylogenetic analyses were performed by a combined sequence dataset of the internal transcribed spacer (ITS) and the partial nuclear large subunit rDNA (nLSU), and a combined sequence dataset of the ITS, partial nLSU, the small subunit mitochondrial rRNA gene (mtSSU), the translation elongation factor 1-α (TEF1), the largest and second largest subunits of RNA polymerase II (RPB1 and RPB2). The eight species formed eight independent lineages with robust support in phylogenies based on both datasets. Illustrated description of the six species including Tremellafibulifera s.s., T. “neofibulifera” and four new species, and discussions with their related species, are provided. A table of the comparison of the important characteristics of nine species in the T.fibulifera complex and a key to the whitish species in Tremella s.s. are provided.

18th Congress of European Mycologists Bioblitz 2019 – Naturalists Contribute to the Knowledge of Mycobiota and Lichenobiota of Białowieża Primeval Forest

A total of 561 records of 233 species of fungi are reported from the Polish part of Białowieża Forest as a result of a short-term inventory that was conducted during the 18th Congress of European Mycologists (September 18–29, 2019). Four species new to Poland (<em>Bryocentria</em><em> brongniartii</em>, <em>Tremella coppinsii</em>, <em>T. </em><em>hypocenomycis</em>, and <em>Zevadia peroccidentalis</em>), and eight species new to Białowieża Primeval Forest (<em>Hypomyces chrysostomus</em>, <em>Hypomyces rosellus</em>, <em>Lachnellula resinaria</em>, <em>Peniophora lycii</em>, <em>Phellinus viticola</em>, <em>Phlebia subochracea</em>, <em>Pronectria anisospora</em>, and <em>Typhula quisquiliaris</em>) were recorded.

Four new species of Tremella (Tremellales, Basidiomycota) based on morphology and DNA sequence data

In the present study, a total of 33 Tremella specimens in China were collected and examined using molecular phylogenetic analysis based on a combined sequence dataset of the nuc rDNA internal transcribed spacer (ITS) region and nuc 28S rDNA D1/D2 domain in conjunction with the morphological characters. Four new species, namely Tremellabasidiomaticola, T.cheejenii, T.erythrina, and T.salmonea, are newly described based on their distinct phylogenetic relationships and the comparison of morphological characters with known Tremella species. Our results indicate a high species diversity of Tremella waiting to be discovered.

A Comprehensive, Automatically Updated Fungal ITS Sequence Dataset for Reference-Based Chimera Control in Environmental Sequencing Efforts

The nuclear ribosomal internal transcribed spacer (ITS) region is the most commonly chosen genetic marker for the molecular identification of fungi in environmental sequencing and molecular ecology studies. Several analytical issues complicate such efforts, one of which is the formation of chimeric—artificially joined—DNA sequences during PCR amplification or sequence assembly. Several software tools are currently available for chimera detection, but rely to various degrees on the presence of a chimera-free reference dataset for optimal performance. However, no such dataset is available for use with the fungal ITS region. This study introduces a comprehensive, automatically updated reference dataset for fungal ITS sequences based on the UNITE database for the molecular identification of fungi. This dataset supports chimera detection throughout the fungal kingdom and for full-length ITS sequences as well as partial (ITS1 or ITS2 only) datasets. The performance of the dataset on a large set of artificial chimeras was above 99.5%, and we subsequently used the dataset to remove nearly 1,000 compromised fungal ITS sequences from public circulation. The dataset is available at http://unite.ut.ee/repository.php and is subject to web-based third-party curation.