Taxonomic recognition of some species-level lineages circumscribed in nominal Rhizoplaca subdiscrepans s. lat. (Lecanoraceae, Ascomycota)

• Published in: PeerJ (San Francisco, CA) CA), 2020-08, Vol.8, p.e9555-e9555, Article e9555
• Main Authors: Szczepańska, Katarzyna, Urbaniak, Jacek, Śliwa, Lucyna
• Format: Article
• Language: English
• Subjects: Ascomycota; Biodiversity; Biogeography; Biological research; Comparative analysis; Cryptic species; Deoxyribonucleic acid; DNA; Ecology; Fungi; Geographical distribution; Habitat preferences; Identification and classification; Lecanora; Lichenized fungi; Lichens; Microscopy; Morphology; Mycology; New combinations; Phylogenetics; Phylogeny; Rhizoplaca; Spacer region; Species; Studies; Taxonomy; Taxonomy (Biology)
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.9555

(Nyl.) R. Sant., a saxicolous, placodioid lichen, is considered to have a worldwide distribution in warm-temperate to boreal-arctic areas in Asia, Europe and North America. However, recent studies have revealed that this species includes five unrecognized species-level lineages-'subd A, B, C, D and E'. During research focused on the diversity of saxicolous lichens in mountainous areas of southern Poland, some interesting representatives of the genus were found. The main aim of our study was to determine the taxonomic status of the collected specimens by means of molecular tools and a comparative analysis of similar herbarium materials. Detailed morphological, anatomical and chemical examinations of reference material from Asia, Europe and North and South America focused primarily on a selected group of lecanoroid taxa with a placodioid thallus. In addition, 21 new generated sequences representing s. lat and were selected for molecular study using the internal transcribed spacer region (ITS rDNA), together with 95 available GenBank sequences mainly from the genus Polish specimens that clustered with members of a potential species-level lineage 'subd E' of complex were recovered. Comprehensive analyses of the lichen group led us to the conclusion that lineage 'subd E' represents s. str. and that the taxon appears to have a limited geographical distribution and specific habitat preferences. Furthermore, some of the recently defined species candidates within s. lat.-'subd D' and 'subd A'-should be assigned to two previously known species of , namely (Brodo) Leavitt, Zhao Xin & Lumbsch and (Poelt) Leavitt, Zhao Xin & Lumbsch, respectively. These two species are characterized by phenotypic features observed as well in analyzed specimens representing lineages 'subd D' and 'subd A'. Moreover, the representatives of these lineages demonstrate some differences in occupied habitat and geographical range that also correspond with the indicated species. Additionally, it was found that B.D. Ryan is a strongly supported monophyletic lineage within and therefore an appropriate new combination for the species is proposed.