The first records of two rare polyporoid fungi Picipes submelanopus and Picipes ulleungensis in Russia

genus Picipes . Most representatives of this genus are known from China. In Russia, out of 29 species of the genus, there are three widespread species of Picipes – P . badius , P . melanopus , P . tubaeformis , and one rare species – P . rhizophilus . Phylogenetic analysis of the nucleotide sequences of selected nrDNA loci obtained from the herbarium materials collected by us, originally assigned to Picipes melanopus , revealed the presence of two rare, morphologically similar species, P . submelanopus and P . ulleungensis , which turned out to be new to Russia. Picipes submelanopus is characterized by a terrestrial fruiting bodies and differentiated from P . melanopus , that grows on dead wood. All specimens of fruiting bodies of Picipes submelanopus collected by us in Western Siberia were found on the roots of woody plants, as in the typе locality in China. Picipes ulleungensis differs from P . melanopus by larger fruiting bodies, slightly larger pores. In order to differentiate Picipes submelanopus and P . ulleungensis from morphologically similar species, in addition to morphological characters and ecological preferences, it is desirable to use DNA barcoding methods .


Introduction
The genus Picipes was described by Ivan Zmitrovich and Aleksandr Kovalenko (Zmitrovich, Kovalenko, 2016) with the type species Picipes badius (Pers.)Zmitr.et Kovalenko.Three species were assigned to the new taxon, including also Picipes melanopus (Pers.)Zmitr.et Kovalenko and P. tubaeformis (P.Karst.)Zmitr.et Kovalenko, segregated from the morphological genus Polyporus P. Micheli ex Adans., belonging to a separate phylogenetic lineage.Earlier, these species were combined into the "Melanopus" morphological group based on the presence of a black cuticle covering the entire or most of the stipe of the basidiomata (Núñez, Ryvarden, 1995).Later, polyporoid fungi of this group were actively studied by mycologists from China, where their high species diversity is observed.Molecular genetic studies made it possible to clarify the taxonomic status and transfer another 10 species to the genus Picipes, and another 18 species were described as new to science in the genus, two of which were transferred to the genus Polyporus s. str.(Dai et al., 2014;Zhou et al., 2016;Cui et al., 2019;Bhunjun et al., 2022;Ji et al., 2022).Thus, based on the data below, the genus Picipes currently includes 29 taxa.

Material and methods
We collected specimens in the Western Siberia, the Novosibirsk Region and the Altai Territory.We took photographs of fresh fungal fruiting bodies, as well as dry basidiomata from the herbarium collection.We used a Zeiss Axio Imager A1 light microscope (Carl Zeiss Microscopy, Germany) for the detailed morphological examination.

Sequence alignments and phylogenetic analyses
We analyzed the Picipes species' complete ITS1-5.8S-ITS2sequenograms in Chromas, version 2.6.6 (http://technelysium.com.au/wp/chromas/).We compared these sequences with the existing data in GenBank using the Nucleotide BLAST tool (Altschul et al., 1990).Based on the BLAST search, we incorporated additional ITS sequences of other Polyporus s. l. species into the analyses.

Sequences and alignment
The total ITS dataset consists of 23 sequences including an outgroup.For this study we produced newly generated ITS sequences.Table provides an overview of the taxa we used, information on the herbarium specimens, GenBank accession numbers, and references.We aligned the sequences online in MAFFT (Katoh et al., 2002), version 7 (http://mafft.cbrc.jp/alignment/server/) using the E-INS-I strategy (Katoh, Toh, 2008).We chose Trametes conchifer (Schwein.)Pilát as an outgroup (Justo, Hibbett, 2011).
Comments.The ML analysis of the ITS1-5.8S-ITS2nrDNA region confirmed that the studied specimen belongs to the Picipes submelanopus (Fig. 2).The species as an independent taxon was introduced only in 2012, based on molecular genetic studies.On a global scale, the species is known from four localities, with a type locality in China.Picipes submelanopus is morphologically similar to P. melanopus.
Picipes submelanopus is characterized by a terrestrial habit, centrally or laterally black-stipitate basidiomata, straw-yellow to honey-yellow pore surface, circular to angular pores, two types of generative hyphae bearing either simple septa or clamp connections, and cylindrical basidiospores.However, Picipes melanopus has smaller pores and clamped generative hyphae only (Xue, Zhou, 2012).All specimens of the species collected by us in Western Siberia were found on the roots of woody plants -on a birch and willow.In the type locality, in China, Picipes submelanopus has also been found on the soil on tree roots (Xue, Zhou, 2012).According to this ecological feature, the species is differentiated from Picipes melanopus, which develops on dead wood.Records from China, Pakistan, and Russia have been confirmed by molecular genetic studies.In Latvia, the species is known from metagenomic soil studies data (Picipes submelanopus, 2023).Distribution.Europe -Estonia; Asia -Russia (in this study), China, South Korea (Tibpromma et al., 2017;Runnel et al., 2021;Ji et al., 2022).
Comments.The ML analysis of the ITS1-5.8S-ITS2nrDNA region confirmed that the studied specimen nests within the Picipes ulleungensis (Fig. 2).The species as an independent taxon was de-Vlasenko V. A. et al.The first records of two rare polyporoid fungi Picipes submelanopus and Picipes ulleungensis... scribed in 2017, based on molecular genetic studies.On a global scale, the species is known from four localities, with a type locality in South Korea.Picipes ulleungensis is morphologically similar to P. melanopus.Specimens of the species, collected by us in Western Siberia, were found on dead wood -on a birch.In the type locality in Korea, Picipes ulleungensis has also been found on a woody plant belonging to the genus Betula -B.platyphylla var.japonica (Tibpromma et al., 2017).Picipes ulleungensis, according to the original description, differs from P. melanopus larger basidiomata and slightly larger pores (5-6 on mm vs. 6-8 on mm).Records from South Korea, China, and Russia have been confirmed by molecular genetic studies.

Fig. 2 .
Fig. 2. The maximum likelihood tree based on ITS1-5.8S-ITS2nrDNA sequences shows the phylogenetic relationships between Picipes submelanopus, P. ulleungensis, and other closely related Polyporus s. l. species.Numbers on the tree demonstrate genetic distances (branches) and bootstrap values (nodes).Each sequence name contains its Gen-Bank access number.

Table
Sequences we used for the alignments with their corresponding GenBank access numbers and references