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| 2. |
- 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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| 3. |
- Articus, Kristina, 1971-
(författare)
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Phylogenetic Studies in Usnea (Parmeliaceae) and Allied Genera
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with the phylogeny of the lichen genus Usnea (Parmeliaceae, Ascomycetes). The relationships and the morphological variation among Usnea species has been studied, as well as the relationship of Usnea to allied genera. Two species, U. florida and U. subfloridana, which earlier were regarded to form two separate species have been synonymized. In an analysis based on sequence data these two taxa formed a monophyletic group of intermixed specimens. Usnea florida and U. subfloridana have earlier been regarded to form a species pair, but the species pairs concept cannot be applied in this case. The morphological characters traditionally used for species recognition of a number of European Usnea species have been analyzed regarding their reliability. The evolution and distribution of the morphological characters was studied in relation to a phylogeny based on sequence data. Most characters proved to be homoplastic in relation to the phylogeny. Few characters were consistent in a clade, and the same character could be inconsistent in another clade. Therefore a combination of several characters is recommended for species recognition. The relationship of Neuropogon to Usnea was investigated based on sequence data. Neuropogon showed to be closely related to Usnea subg. Usnea. The subgenera Eumitria and Dolichousnea formed the sister group to the clade comprising subg. Usnea and Neuropogon. Usnea is paraphyletic in this investigation. Eumitria is treated as a genus and the subgenus Dolichousnea is elevated to generic rank. The position of Usnea, Neuropogon, Eumitria, and Dolichousnea in the family Parmeliaceae was investigated based on a phylogeny obtained by sequence data. Protousnea probably forms the sister group to the clade of Usnea, Neuropogon, Eumitria, and Dolichousnea. Several monophyletic groups in the family Parmeliaceae were identified.
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| 4. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 5. |
- Dillman, Karen L., et al.
(författare)
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New records, range extensions and nomenclatural innovations for lichens and lichenicolous fungi from Alaska, USA
- 2012
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Ingår i: Herzogia. - : Herzogia. - 0018-0971. ; 25:2, s. 177-210
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Tidskriftsartikel (refereegranskat)abstract
- New records, range extensions and nomenclatural innovations for lichens and lichenicolous fungi from Alaska, U.S.A. - Herzogia 25: 177-210. Surveys of lichens and lichenicolous fungi have been taking place in the U.S. state of Alaska for more than 160 years, but until now assessing the full extent of their diversity has been hampered by the lack of a comprehensive and synonymized baseline inventory. In this paper we will begin to redress this by resolving outstanding nomenclatural issues and providing voucher data for a forthcoming catalog of Alaskan lichens, specifically: 1) synonymization,and/or resolution of status of species previously reported from Alaska, with emphasis on Alaskan types; 2) species new to the Alaska lichen biota; and 3) biogeographically significant new records from within Alaska. We report 91 species new to the flora of Alaska, including 65 lichens, three saprophytic calicioid fungi and 23 lichenicolous fungi. Of these, we report thirteen species, Biatora sphaeroidiza, Biatorella conspurcans, Chaenothecopsis arthoniae, Collemopsidium foveolatum, Dactylospora frigida, Halospora discrepans, Lecanora bryopsora, Opegrapha geographicola, Peltigera lyngei, Petractis clausa, Protoblastenia cyclospora, Thelocarpon impressellum and Usnea cylindrica as new to North America. In addition, Arthonia pruinata and Flavocetraria minuscula are new to Canada and Adelococcus alpestris new to the United States. We further place the following five names into synonymy: Lecania disceptans (Nyl.) Lynge [= Halecania alpivaga (Th.Fr.) M.Mayrhofer], Lecidea pallidella Nyl. [= Lecania subfuscula (Nyl.) S.Ekman], Lempholemma triptodes (Nyl.) Zahlbr. Leciophysma finmarkicum Th.Fr.), Polyblastia obtenta (Nyl.) Lynge [= Sporodictyon terrestre (Th.Fr.) S.Savic & Tibell], and Verrucaria pernigrata Nyl. [= Protothelenella sphinctrinoides (Nyl.) H.Mayrhofer & Poelt]. We propose restoring the long overlooked taxon Polyblastia exalbida (Nyl.) Zahlbr., currently known only from Alaska, to the North American lichen checklist. Finally, we propose the new combination Puttea caesia (Fr.) M.Svensson & T.Sprib. to replace Lecidea symmictella Nyl., which becomes a synonym.
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| 6. |
- Divakar, Pradeep K., et al.
(författare)
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Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi
- 2015
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 208:4, s. 1217-1226
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Tidskriftsartikel (refereegranskat)abstract
- We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes.
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| 7. |
- Gilbert Temu, Stella, 1987-
(författare)
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Lichens in Mountain Rainforests of Tanzania : Studies of Usnea and Calicioids
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lichens occur in various habitats. They often have narrow niches and are sensitive to environmental changes leading to their use as bioindicators of environmental disturbances and conditions; air and heavy metal pollution, agricultural toxins, assessing forest continuity and drought tolerance. Lichenological studies in Africa, particularly in Tanzania, have been scarce, and those available have been mainly based on morphology and chemistry data. The aim of my doctorate was to investigate lichens, in particular Usnea and calicioid lichens in mountain rain forests in Tanzania, using both traditional and molecular approaches.Paper I and II explored Usnea subgenus Eumitria. In paper I, molecular, morphological and chemical methods were utilized. A phylogeny of Eumitria from Tanzania based on a four-markers data set supported monophyly of Eumitria, where sixty-two new sequences were reported. In paper II additional specimens of the Usnea pectinata aggregate from Tanzania and São Tomé and Príncipe were studied, and forty-two specimens were examined by an integrative approach (molecular, morphological, chemical data). The U. pectinata aggregate was monophyletic, containing several subclades, some characterized morphologically and chemically. Paper III and IV focused on calicioids. Paper III summed up earlier information on Tanzanian calicioids along with new discoveries (twenty-six species), with notes on their habitats and distributions. Chaenothecopsis kilimanjaroensis was described as new, Chaenotheca hispidula and Pyrgillus cambodiensis new to Africa: Calicium lenticulare and Chaenothecopsis debilis new to Tanzania. In paper IV, Coniocybe was revised and emended to include along with its type C. furfuracea, also C. brachypoda and C. confusa. A three marker phylogeny was used to infer its phylogenetic position and Coniocybe eufuracea was described as new.This thesis contributes to the knowledge of the lichens in Tanzania and Africa at large by building capacity in lichenology and its applications for future research. It provided integrated data for Usnea species from Africa, adding to the knowledge of this difficult group (only two sequences of Usnea from Africa have previously been published). It provided new information on calicioid lichens in Tanzania and by uncovering a rich diversity in both of the groups studied provided a foundation for further investigations of lichen biodiversity.
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| 8. |
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| 9. |
- Temu, Stella G., et al.
(författare)
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Molecular, morphological and chemical variation of the Usnea pectinata aggregate from Tanzania, São Tomé and Príncipe
- 2022
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Ingår i: The Lichenologist. - : Cambridge University Press. - 0024-2829 .- 1096-1135. ; 54:5, s. 291-298
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the molecular, chemical and morphological variation in the Usnea pectinata aggregate using 42 specimens, 22 from Tanzania and 20 from São Tomé and Príncipe. A total of 31 sequences (13 ITS, 13 nuLSU and 5 RPB1) were generated. The results are presented in two phylogenies: first a three-markers ‘backbone’ phylogeny for the U. pectinata aggregate, where six distinct, strongly supported subclades indicate considerable genetic variation in the dataset; and second, an ITS phylogeny with 47 terminals along with a mapping of morphological and chemistry data. Several well-supported monophyletic clades were recovered in both phylogenies and these may well represent separate species in the complex referred to here as the U. pectinata aggregate. Three morphotypes characterized by axis pigmentation and four by branch shape were noted. Six chemotypes were observed.
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| 10. |
- Temu, Stella, et al.
(författare)
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Phylogeny of the subgenus Eumitria in Tanzania
- 2019
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Ingår i: Mycology. - : Informa UK Limited. - 2150-1203 .- 2150-1211. ; 10:4, s. 250-260
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Tidskriftsartikel (refereegranskat)abstract
- Several Usnea species in subgenus Eumitria (Parmeliaceae, lichenized Ascomycota) have been described from East Africa in the past decades. These have been based on morphology and chemistry data while molecular studies remain very limited. In this paper we are for the first time publishing phylogenetic analyses along with morphological and chemical data for Eumitria. A total of 62 new sequences of Eumitria (26 ITS, 20 nuLSU, 6 MCM7, 10 RPB1) were generated in this study. nuLSU, MCM7 and RPB1 sequences are here for the first time reported for U. baileyi. A phylogeny of subgenus Eumitria from Tanzania based on Bayesian and maximum likelihood analyses of a concatenated four-loci data set is presented, confirming the monophyly of Eumitria. Further, secondary chemistry and variation in characters, such as the pigmentation of the central axis and branch shape were investigated.
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