Keywords: ANTARCTICA/ NEW TAXA/ KEYS
Abstract: [Many genera and species; keys. New: Verrucaria simplei nom. nov. (for V. maura vain. non Wahlenb.), Sphaerophorus lacunosus (Tuck.) comb. nov., Lecidea brabantica nom. nov. (for L. subcongrua Vain. non Nyl.), Catocarpus gerlachei (Vain.) comb. nov., Cladina laevigata (Vain.) comb. nov., C. vicaria (Sant.) comb. nov., Cladonia propagulifera (Vain.) comb. nov., Agyrophora nana (Vain.) comb. nov., Omphalodiscus bakeri nom. nov. (for Umbilicaria rugosa Dodge & Baker non Hook.), O. eximius (Hue) comb. nov., O spongiosus var. subvirginis (Frey & Lamb) comb. nov., Biatorella chrysea (Dodge & Baker) comb. nov., Biatorelliopsis antarctica (Murray) comb. nov., B. cerbriformis (Dodge) comb. nov., Sarcogyne medusula sp. nov., Ochrolechia huei nom. nov. (for O. tartarea var. frigida Hue non (Sw.) Körb.), Lecanora leptacinodes (Vain.) comb. nov., Omphalodina aspidophora (Vain.) comb. nov., with fo. aterrima (Hue) comb. nov., O. charcotiana (Hue) comb. nov., O. daltoniana (Hook. f. & Tayl.) comb. nov., O. errabunda (Hue) comb. nov., O. exsulans (Th. Fr.) comb. nov., O. johnstonii (Dodge) comb. nov., O. leucomelaena (Hue) comb. nov., O. mcleanii (Dodge) comb. nov., O. priestleyi (Dodge) comb. nov., O. siplei (Dodge & Baker) comb. nov., Parmelia disseminata (Hue) comb. nov., P. fuscella (Hue) comb. nov., Usnea aurantiacoatra fo. egentissima (Lamb) comb. nov., U. subpolaris (Lamb.) comb. nov., U. substgrigulosa (Lamb) comb. nov., U. trachycarpoides (Vain.) comb. nov., Protoblastenia hallettensis (Murray) comb. nov., Huea austroshetlandica (Zahlbr.) comb. nov., Caloplaca mawsonii (Dodge) comb. nov., Gasparrinia gainii (Hue) comb. nov., Xanthoria siplei (Dodge & Baker) comb. nov., Polycaulonia antarctica (Vain.) comb. nov., P. prostrata (Hue) comb. nov., Buellia conspicua fo. cervinogranulata (Lamb) comb. nov., fo. incrassata (Lamb) comb. nov., fo. verrucosa (Lamb) comb. nov., B. filsonii nom. nov. (for B. aff. subpedicellata Fils. non B. subpedicellata (Hue) Darb.), B. gerlachei (Vain.) comb. nov., B. hypopoichila (Vain.) comb. nov., B. lambii nom. nov. (for B. punctata Lmab non Mass.), B. lutea sp. nov., B. racovitzae nom. nov. (for B. prothallina var. indissimilis Vain. non B. indissimilis B. de Lesd.) Diplotomma cremea (Hue) comb. nov. with fo. incrassata (Hue) comb. nov., D. granulosa (Darb.) comb. nov., D. nelsonii (Darb.) comb. nov., D. papillata (Sommerf.) comb. nov., D. siplei (Dodge & Baker) comb. nov., Diploicia actinobola (Hue) comb. nov., D. huei (Dodge) comb. nov., D. latemarginata (Darb.) comb. nov., D. llanoi (Dodge) comb. nov., D. stipiatat (Dodge) comb. nov., Redonia chilena sp. nov., R. cladocarpiza (Lamb) comb. nov., Rinodina floccosa (Dodge & Baker) comb. nov., Beltraminia babingtonii (Hook. f. & Tayl.) comb. nov., B. frigida (Darb.) comb. nov., B. molholmii (Dodge) comb. nov., B. petermannii (Hue) comb. nov., B. rudolphii (Dodge) comb. nov., B. stipitata (Dodge) comb. nov., Dirinaria autenboeri (Dodge) comb. nov., D. leoniae (Hue) comb. nov.]
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Keywords: AIR POLLUTION/ ANTARCTIC/ BIOINDICATORS/ EPILITHIC/ HEAVY METALS
Abstract: 1 fig. 3 tab.
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Keywords: ANTARCTICA/ LICHENS/ MOSSES/ PBDES/ POPS/ STABLE ISOTOPES/ ANTARCTICA/ LICHENS/ MOSSES/ PBDES/ POPS/ STABLE ISOTOPES/ ANIMALS/ CORRELATION METHODS/ ISOTOPES/ POLYCHLORINATED BIPHENYLS/ VEGETATION/ ORGANIC POLLUTANTS/ CARBON 13/ CHLORPHENOTANE/ HEXACHLOROBENZENE/ LINDANE/ NITROGEN 13/ NITROGEN 15/ POLYBROMINATED DIPHENYL ETHER/ POLYCHLORINATED BIPHENYL/ ABSORPTION/ BIOACCUMULATION/ BIOGEOCHEMISTRY/ CARBON ISOTOPE/ DICOTYLEDON/ LICHEN/ MANURE/ MOSS/ NITROGEN ISOTOPE/ ORGANIC POLLUTANT/ PBDE/ PERSISTENCE/ POLLUTANT SOURCE/ POLLUTANT TRANSPORT/ SAMPLING/ STABLE ISOTOPE/ VEGETATION MAPPING/ ABSORPTION/ ANGIOSPERM/ ANTARCTICA/ ARTICLE/ BIOGEOCHEMICAL CYCLE/ BRACHYTECIUM/ COLOBANTHUS QUITENSIS/ ENVIRONMENTAL EXPOSURE/ LICHENS/ MOSS/ NITROGEN UPTAKE/ NONHUMAN/ PERSISTENT ORGANIC POLLUTANT/ POLLUTANT/ SANIONIA UNCINATA/ SYNTRICHIA PRINCEPS/ USNEA ANTARCTICA/ USNEA AURANTIACO/ VEGETATION/ ANTARCTICA/ KING GEORGE ISLAND/ SOUTH SHETLAND ISLANDS/ ANIMALIA/ BRACHYTECIUM/ BRYOPHYTA/ COLOBANTHUS QUITENSIS/ MAGNOLIOPHYTA/ SANIONIA UNCINATA/ SYNTRICHIA/ USNEA ANTARCTICA/ USNEA AURANTIACOATRA
Abstract: Vegetation samples from King George Island, Antarctica (62°05'S, 058°23'W) were collected in the austral summer of 2004-2005. Lichens (Usnea aurantiaco-atra and Usnea antarctica), mosses (Sanionia uncinata, Syntrichia princeps and Brachytecium sp.), and one angiosperm (Colobanthus quitensis) species were analyzed for persistent organic pollutants as well as ?13C and ?15N stable isotopes. The following contaminants were found above the method detection limit (MDL): HCB (0.141-1.06ngg-1 dry weight), HCHs (
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Keywords: ANTARCTIC FLORA/ ANTARCTICA/ COLOBANTHUS QUITENSIS/ CUSHION PLANTS/ DESCHAMPSIA ANTARCTICA/ MOSSES/ NURSE PLANTS/ POSITIVE INTERACTION/ SANIONIA/ USNEA ANTARCTICA/ USNEA AURANTIACOATRA
Abstract: A recent article published by Molina-Montenegro et al. (Journal of Vegetation Science24: 463) examines the association of Antarctic native plant and lichen species to the lichen Usnea antarctica on Fildes Peninsula, King George Island, maritime Antarctica. The authors report that on two sites, five out of 13 and four out of 11 species of lichens and mosses were spatially associated with U. antarctica, suggesting positive interactions between them. Although Deschampsia antarctica does not grow naturally associated with U. antarctica, Molina-Montenegro et al. carried out a transplantation experiment to demonstrate that the macrolichen acts as a nurse plant, improving the survival of the grass. Serious conceptual and methodological discrepancies emerge from a critical evaluation of this study, challenging their conclusions. First, we suspect that the author confused some lichen taxa, and we also disagree with macrolichens being treated as cushion plants, because rootless, poikilohydric and poikilothermic thallophytes such as lichens are unable to create a stable, enclave-like microhabitat as vascular cushion plants do. Indeed, a critical evaluation of some of the micro-environmental parameters measured indicates that there are no biologically meaningful differences between the U. antarctica thalli and surrounding open areas. Second, the lack of consideration of the life history of the species under study leads to confusion when (a) referring to the succession sequence of species that colonize the studied area and (b) interpreting the putative distribution patterns promoted by Usnea versus the substrate preferences of associated species. Third, the authors intend to demonstrate experimentally that Usnea can facilitate the survival of D. antarctica plants, transplanting adult plants and not seedlings between the lichen thalli, and it is not clear how the grass was planted
URL: http://dx.doi.org/10.1111/jvs.12122
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Keywords: CARBON/ CARBON 14/ ANTARCTICA/ ARTICLE/ CALIBRATION/ CLIMATE CHANGE/ CONTROLLED STUDY/ ENVIRONMENTAL CHANGE/ FUNGUS GROWTH/ LICHEN (ORGANISM)/ NONHUMAN/ SUMMER/ THALLUS/ USNEA ANTARCTICA/ USNEA AURANTIACOATRA/ WINTER
Abstract: The ages of a fruticose lichen of Usnea aurantiacoatra (Jacq.) Bory, from Fildes Peninsula, King George Island, Southwest Antarctic, were determined by radiocarbon (14C), and it is 1993-1996 at bottom and 2006-2007 at top of the lichen branch. The growth rates of U. aurantiacoatra calculated are 4.3 to 5.5 mm year-1 based on its length and ages. The comparisons show that the growth rates of U. aurantiacoatra are higher than those of U. antarctica (0.4 to 1.1 mm year21). The growth rates of fruticose lichens are always higher, usually >2 mm year-1, than those of crustose ones, usually <1 mm year-1, in polar areas. A warming trend on Fildes Peninsula is recorded in the period from 1969 to 2010 obviously: the mean annual temperature rose from -2.75 to -1.9°C and the average temperature of summer months from 0.95 to 1.4°C, as well as the average temperature of winter months from -6.75 to -5.5°C. The alteration of lichen growth rates in polar areas may respond to the climatic and environmental changes, and the lichens may act as bio-monitor of natural condition. © 2014 Li et al.
URL: http://dx.doi.org/10.1371/journal.pone.0100735
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Keywords: ANTARCTIC/ LICHENS/ LICHENIZED/ MOLECULAR PHYLOGENETICS/ PHOTOSYNTHESIS/ TREBOUXIA
Abstract: Lichens, as typical obligate associations between lichenized fungi and their photosynthetic partners, are dominant in Antarctica. Three Antarctic lichens, Ochrolechia frigida, Umbilicaria antarctica, and Usnea aurantiacoatra with different growth forms, were sampled nearby the Great Wall Station, King George Island. Molecular data revealed that the photosynthetic algae in these three lichens were Trebouxia jamesii. The net photo− synthesis (Pn) of three individuals from these species, together with environmental factors such as light and temperature, were recorded by CO2 gas exchange measurements using a CI−340 portable photosynthetic system in situ. Differences between T(leaf) (the temperature of the thalli) and T(air) (the air temperature) for these lichens were not consistent, which reflected that environment and the growth form of thalli could affect T(leaf) significantly. Strong irradiation was expected to have adverse effects on Pn of Ochrolechia frigida and Umbilicaria antarctica whose thalli spread flat; but this photoinhibition had little effect on Usnea aurantiacoatra with exuberant tufted thallus. These results indicated that photosynthetic activity in lichens was affected by the growth forms of thalli besides microhabitat factors. One species of lichenized alga could exhibit diversified types of photosynthetic behavior when it was associated with various lichenized fungi in different microhabitats. It will be helpful for understanding how lichens are able to adapt to and colonize in extreme environments.
URL: http://www.degruyter.com/view/j/popore.2015.36.issue-2/popore-2015-0012/popore-2015-0012.xml
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Abstract: The ability to separate similar species is of crucial importance for studies in population and conservation genetics. Lichens, symbioses between fungi and one or more photosynthetic organisms, are the most important primary producers in Antarctic terrestrial habitats. The two common lichens Usnea antarctica and U. aurantiacoatra have traditionally been separated based on their reproductive mode: U. antarctica forms soredia containing both symbiotic partners while U. aurantiacoatra displays sexual reproduction. Previous molecular analysis based on ITS and RPB1 genes did not find evidence to reliably split the two taxa. It has thus been suggested to treat them as a single species. As part of ongoing projects on the population structure of Antarctic lichens we present here evidence from microsatellite data clearly supporting the distinction between both species. These findings have an impact on sampling design for population genetic studies and the development of conservation strategies.
URL: https://www.researchgate.net/publication/320373585_Sexuality_clonality_and_dispersal_in_two_Antarctic_lichens
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Abstract: Premise of the study: Usnea antarctica and U. aurantiacoatra (Parmeliaceae) are common lichens in the maritime Antarctic. These species share the same habitats on King George Island (South Shetland Islands, Antarctica) and are distinguishable based on reproductive strategies. Methods and Results: We developed 23 fungus-specific simple sequence repeat (SSR) markers that cross-amplify between the two species. We used a low-coverage genome-skimming approach on one sample of each species to identify SSR repeats in the two species. Primers were designed for 3–4-bp repeats, and only the loci common to both species were selected for further analyses. Seventy-seven samples of the two species were selected to assess fungal specificity, genetic variability, and linkage of the markers. In addition, we tested cross-amplification in other Usnea species. Conclusions: The 23 newly designed SSR markers are suitable for population genetic and phylogeographic studies of Usnea species.
URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5628029/
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Abstract: Seven lichens (Usnea antarctica and U. aurantiacoatra) and nine moss samples (Sanionia uncinata) collected in King George Island were analyzed using instrumental neutron activation analysis, and concentration of major and trace elements was calculated. For some elements, the concentrations observed in moss samples were higher than corresponding values reported from other sites in the Antarctica, but in the lichens, these were in the same range of concentrations. Scanning electron microscopy (SEM) and statistical analysis showed large influence of volcanic-origin particles. Also, the interplanetary cosmic particles (ICP) were observed in investigated samples, as mosses and lichens are good collectors of ICP and micrometeorites.
Countries/Continents: Antarctica
URL: https://link.springer.com/article/10.1007/s11356-017-0431-2
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Abstract: The single celled green alga Coccomyxa antarctica Shunan Cao & Qiming Zhou, sp. nov. was isolated from the Antarctic torrential lichen Usnea aurantiacoatra (Jacq.) Bory. It is described and illustrated based on a comprehensive study of its morphology, ultrastructure, ecology and phylogeny. C. antarctica is a lichenicolous alga which has elongated cells and contains a parietal chloroplast as observed under the microscope. C. antarctica is clearly different from other species by phylogenetic analysis (ITS rDNA and SSU rDNA sequences), also it differs from its phylogenetic closely species C. viridis by its larger cell size.
URL: https://phytokeys.pensoft.net/article/25360/
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Abstract: Neuropogonoid species in the lichen-forming fungal genus Usnea exhibit great morphological variation that can be misleading for delimitation of species. We specifically focused on the species delimitation of two closely-related, predominantly Antarctic species differing in the reproductive mode and representing a so-called species pair: the asexual U. antarctica and the sexual U. aurantiacoatra. Previous studies have revealed contradicting results. While multi-locus studies based on DNA sequence data provided evidence that these two taxa might be conspecific, microsatellite data suggested they represent distinct lineages. By using RADseq, we generated thousands of homologous markers to build a robust phylogeny of the two species. Furthermore, we successfully implemented these data in fine-scale population genomic analyses such as DAPC and fineRADstructure. Both Usnea species are readily delimited in phylogenetic inferences and, therefore, the hypothesis that both species are conspecific was rejected. Population genomic analyses also strongly confirmed separated genomes and, additionally, showed different levels of co-ancestry and substructure within each species. Lower co-ancestry in the asexual U. antarctica than in the sexual U. aurantiacoatra may be derived from a wider distributional range of the former species. Our results demonstrate the utility of this RADseq method in tracing population dynamics of lichens in future analyses.
URL: https://mycokeys.pensoft.net/article/29093/element/5/31//
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Abstract: Lichens are symbiotic associations consisting of a fungal (mycobiont) and one or more photosynthetic (photobionts) partners and are the dominant component, and most important primary producers, of Antarctic terrestrial ecosystems. The most common lichens in the maritime Antarctic are Usnea antarctica and U. aurantiacoatra, a so-called “species pair” in which U. antarctica shows asexual reproduction and propagation via soredia and U. aurantiacoatra forms ascospores in apothecia. Previous molecular analyses were not able to unambiguously distinguish the two morphotypes as species. Therefore, the goal of this study was to find out whether fast-evolving SSR (single sequence repeat) markers are able to separate morphotypes more clearly and help to clarify their taxonomy. We investigate 190 individuals from five mixed stands of both morphotypes collected in King George Island and Elephant Island (South Shetland Islands, Antarctica). Based on 23 microsatellite markers designed from sequenced genomes, discriminant analysis of principal components (DAPC), Bayesian clustering analysis, and coalescent-based estimation of gene flow show clear evidence for the existence of two different species distinguishable by reproductive mode. We did not detect any statistical association between genetic clusters and three previously reported chemical races of each species.
URL: https://www.tandfonline.com/doi/abs/10.1080/00275514.2018.1512304?journalCode=umyc20
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Abstract: We present an exhaustive analysis of the ITS barcoding marker in the genus Usnea s.lat., separated into DolichoUsnea, Eumitria, and Usnea including the subgenus Neuropogon, analyzing 1,751 accessions. We found only a few low-quality accessions, whereas information on voucher specimens and accuracy and precision of identifications was of subpar quality for many accessions. We provide an updated voucher table, alignment and phylogenetic tree to facilitate DNA barcoding of Usnea, either locally or through curated databases such as UNITE. Taxonomic and geographic coverage was moderate: while DolichoUsnea and subgenus Neuropogon were well-represented among ITS data, sampling for Eumitria and Usnea s.str. was sparse and biased towards certain lineages and geographic regions, such as Antarctica, Europe, and South America. North America, Africa, Asia and Oceania were undersampled. A peculiar situation arose with New Zealand, represented by a large amount of ITS accessions from across both major islands, but most of them left unidentified. The species pair Usnea antarctica vs. U. aurantiacoatra was the most sampled clade, including numerous ITS accessions from taxonomic and ecological studies. However, published analyses of highly resolved microsatellite and RADseq markers showed that ITS was not able to properly resolve the two species present in this complex. While lack of resolution appears to be an issue with ITS in recently evolving species complexes, we did not find evidence for gene duplication (paralogs) or hybridization for this marker. Comparison with other markers demonstrated that particularly IGS and RPB1 are useful to complement ITS-based phylogenies. Both IGS and RPB1 provided better backbone resolution and support than ITS; while IGS also showed better resolution and support at species level, RPB1 was less resolved and delineated for larger species complexes. The nuLSU was of limited use, providing neither resolution nor backbone support. The other three commonly employed protein-coding markers, TUB2, RPB2, and MCM7, showed variable evidence of possible gene duplication and paralog formation, particularly in the MCM7, and these markers should be used with care, especially in multimarker coalescence approaches. A substantial challenge was provided by difficult morphospecies that did not form coherent clades with ITS or other markers, suggesting various levels of cryptic speciation, the most notorious example being the U. cornuta complex. In these cases, the available data suggest that multimarker approaches using ITS, IGS and RPB1 help to assess distinct lineages. Overall, ITS was found to be a good first approximation to assess species delimitation and recognition in Usnea s.lat., as long as the data are carefully analyzed, and reference sequences are critically assessed and not taken at face value. In difficult groups, we recommend IGS as a secondary barcode marker, with the option to employ more resource-intensive approaches, such as RADseq, in species complexes involving so-called species pairs or other cases of disparate morphology not reflected in the ITS or IGS. Attempts should be made to close taxonomic and geographic gaps especially for the latter two markers, in particular in Eumitria and Usnea s.str. and in the highly diverse areas of North America and Central America, Africa, Asia, and Oceania.
URL: https://pfsyst.botany.pl/Two-decades-of-DNA-barcoding-in-the-genus-Usnea-n-Parmeliaceae-how-useful-and-reliable,130373,0,2.html
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Abstract: Aim The homogenisation of historically isolated gene pools has been recognised as one of the most serious conservation problems in the Antarctic. Lichens are the dominant components of terrestrial biotas in the Antarctic and in high mountain ranges of southern South America. We study the effects of dispersal strategy and migration history on their genetic structure to better understand the importance of these processes and their interplay in shaping population structure as well as their relevance for conservation. Location Maritime Antarctic and southern South America. Methods Populations of three fruticose lichen species, Usnea aurantiacoatra, U. antarctica and Cetraria aculeata, were collected in different localities in the Maritime Antarctic and southern South America. Usnea aurantiacoatra reproduces sexually by ascospores, whereas the other two species mostly disperse asexually by symbiotic diaspores. Samples were genotyped at 8–22 microsatellite loci. Different diversity and variance metrics, Bayesian cluster analyses and Discriminant Analysis of Principal Components (DAPC) were used to study population genetic structure. Historical migration patterns between southern South America and the Antarctic were investigated for U. aurantiacoatra and C. aculeata by approximate Bayesian computation (ABC). Results The two vegetative species display lower levels of genetic diversity than U. aurantiacoatra. Antarctic populations of C. aculeata and South American populations of U. aurantiacoatra display much stronger genetic differentiation than their respective counterparts on the opposite side of the Drake Passage. Usnea antarctica was not found in South America but shows comparably low levels of genetic differentiation in Antarctica as those revealed for U. aurantiacoatra. Phylogeographic histories of lichens in the region differ strongly with recent colonisation in some instances and potential in situ persistence during Last Glacial Maximum (LGM) in others. Patterns of genetic diversity indicate the presence of glacial refugia near Navarino Island (South America) and in the South Shetland Islands. ABC analyses suggest that C. aculeata colonised the Antarctic from Patagonia after the LGM. Results for U. aurantiacoatra are ambiguous, indicating a more complex population history than expressed in the simplified scenarios. Main Conclusions Mode of propagation affects levels of genetic diversity, but the location of glacial refugia and postglacial colonisation better explains the diversity patterns displayed by each species. We found evidence for glacial in situ survival of U. aurantiacoatra on both sides of the Drake Passage and postglacial colonisation of Antarctica from South America by C. aculeata. Maintaining the strong genetic differentiation of Antarctic populations of C. aculeata requires strict conservation measures, whereas populations of U. aurantiacoatra are exposed to a much lower risk due to their higher diversity and connectivity.
URL: https://onlinelibrary.wiley.com/doi/10.1111/jbi.14101
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Abstract: Lichens are symbiotic associations resulting from interactions among fungi (primary and secondary mycobionts), algae and/or cyanobacteria (primary and secondary photobionts), and specific elements of the bacterial microbiome associated with the lichen thallus. The question of what is a species, both concerning the lichen as a whole and its main fungal component, the primary mycobiont, has faced many challenges throughout history and has reached new dimensions with the advent of molecular phylogenetics and phylogenomics. In this paper, we briefly revise the definition of lichens and the scientific and vernacular naming conventions, concluding that the scientific, Latinized name usually associated with lichens invariably refers to the primary mycobiont, whereas the vernacular name encompasses the entire lichen. Although the same lichen mycobiont may produce different phenotypes when associating with different photobionts or growing in axenic culture, this discrete variation does not warrant the application of different scientific names, but must follow the principle "one fungus = one name". Instead, broadly agreed informal designations should be used for such discrete morphologies, such as chloromorph and cyanomorph for lichens formed by the same mycobiont but with either green algae or cyanobacteria. The taxonomic recognition of species in lichen-forming fungi is not different from other fungi and conceptual and nomenclatural approaches follow the same principles. We identify a number of current challenges and provide recommendations to address these. Species delimitation in lichen-forming fungi should not be tailored to particular species concepts but instead be derived from empirical evidence, applying one or several of the following principles in what we call the LPR approach: lineage (L) coherence vs. divergence (phylogenetic component), phenotype (P) coherence vs. divergence (morphological component), and/or reproductive (R) compatibility vs. isolation (biological component). Species hypotheses can be established based on either L or P, then using either P or L (plus R) to corroborate them. The reliability of species hypotheses depends not only on the nature and number of characters but also on the context: the closer the relationship and/or similarity between species, the higher the number of characters and/or specimens that should be analyzed to provide reliable delimitations. Alpha taxonomy should follow scientific evidence and an evolutionary framework but should also offer alternative practical solutions, as long as these are scientifically defendable. Taxa that are delimited phylogenetically but not readily identifiable in the field, or are genuinely cryptic, should not be rejected due to the inaccessibility of proper tools. Instead, they can be provisionally treated as undifferentiated complexes for purposes that do not require precise determinations. The application of infraspecific (gamma) taxonomy should be restricted to cases where there is a biological rationale, i.e., lineages of a species complex that show limited phylogenetic divergence but no evidence of reproductive isolation. Gamma taxonomy should not be used to denote discrete phenotypical variation or ecotypes not warranting the distinction at species level. We revise the species pair concept in lichen-forming fungi, which recognizes sexually and asexually reproducing morphs with the same underlying phenotype as different species. We conclude that in most cases this concept does not hold, but the actual situation is complex and not necessarily correlated with reproductive strategy. In cases where no molecular data are available or where single or multi-marker approaches do not provide resolution, we recommend maintaining species pairs until molecular or phylogenomic data are available. This recommendation is based on the example of the species pair Usnea aurantiacoatra vs. U. antarctica, which can only be resolved with phylogenomic approaches, such as microsatellites or RADseq. Overall, we consider that species delimitation in lichen-forming fungi has advanced dramatically over the past three decades, resulting in a solid framework, but that empirical evidence is still missing for many taxa. Therefore, while phylogenomic approaches focusing on particular examples will be increasingly employed to resolve difficult species complexes, broad screening using single barcoding markers will aid in placing as many taxa as possible into a molecular matrix. We provide a practical protocol how to assess and formally treat taxonomic novelties. While this paper focuses on lichen fungi, many of the aspects discussed herein apply generally to fungal taxonomy. The new combination Arthonia minor (Lücking) Lücking comb. et stat. nov. (Bas.: Arthonia cyanea f. minor Lücking) is proposed.
Notes: New: Arthonia minor (Lücking) Lücking (≡ A. cyanea f. minor Lücking).
URL: https://link.springer.com/article/10.1007/s13225-021-00477-7
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Number of hits shown/total: 15/15.
Number of records in database: 53500.
Current date: 2024.04.18.OK