| 1. |
- Hognabba, Filip, et al.
(författare)
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Phylogenetic position of the crustose Stereocaulon species
- 2014
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Ingår i: The Lichenologist. - 0024-2829 .- 1096-1135. ; 46:1, s. 103-114
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic relationships of Stereocaulon with emphasis on the crustose taxa were studied based on nuclear ribosomal ITS1-5.8S-ITS2 and partial beta-tubulin sequences. The placement of four of the six crustose species currently included in the genus has previously been confirmed based on molecular data. It has, however, remained unresolved whether the crustose growth form is a plesiomorphic or apomorphic feature within Stereocaulon, due to contradictory placements of the crustose species in earlier studies. The aim of this study was to clarify the position of the crustose species by including additional data, especially of S. nivale and S. plicatile, which have not been included in previous analyses. The inclusion of S. plicatile in the genus is of particular interest as it is the only species in the genus with submurifrom to muriform ascospores. Altogether 37 specimens representing 31 species of the ingroup, including all the crustose Stereocaulon species, were incorporated in the analyses. Conventional, as well as direct optimization parsimony, maximum likelihood and Bayesian analyses were performed. The results show that the crustose species do not form a monophyletic entity and that the crustose growth form is a plesiomorphic feature within Stereocaulon. The crustose S. nivale and S. plicatile are nested within the genus and their inclusion in Stereocaulon is thereby confirmed. The nested position of S. plicatile indicates that the submuriform to muriform spore type has been gained independently within the genus. Here, S. plicatile is also reported for the first time from Scandinavia.
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| 2. |
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| 3. |
- Schoch, Conrad L., et al.
(författare)
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Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi
- 2014
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Ingår i: Database: The Journal of Biological Databases and Curation. - : Oxford University Press (OUP). - 1758-0463. ; 2014:bau061, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.
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| 4. |
- Zamora, Juan Carlos, et al.
(författare)
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Considerations and consequences of allowing DNA sequence data as types of fungal taxa
- 2018
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Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
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Tidskriftsartikel (refereegranskat)abstract
- Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
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