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.
URL: http://onlinelibrary.wiley.com/doi/10.1111/nph.13553/abstract
[Edit/Delete]
[Upload PDF/URL]
Abstract: Historical mass extinction events had major impacts on biodiversity patterns. The most recent and intensively studied event is the Cretaceous – Paleogene (K-Pg) boundary (ca. 66 million years ago [MYA]). However, the factors that may have impacted diversification dynamics vary across lineages. We investigated the macroevolutionary dynamics with a specific focus on the impact of major historical events such as the K-Pg mass extinction event on two major subclasses – Lecanoromycetidae and Ostropomycetidae – of lichen-forming fungi and tested whether variation in the rate of diversification can be associated with the evolution of a specific trait state - macrolichen. Our results reveal accelerated diversification events in three families of morphologically complex lichen-forming fungi – Cladoniaceae, Parmeliaceae, and Peltigeraceae – which are from the subclass Lecanoromycetidae and mostly composed of macrolichens, those that form three dimensional structures. Our RTT plot result for the subclass Lecanoromycetidae also reveals accelerated diversification. Changes in diversification rates occurred around the transition between Mesozoic and Cenozoic eras and was likely related to the K-Pg mass extinction event. The phylogenetic positions for rate increases estimated based on marginal shift probability are, however, scattered from 100 to 40 MYA preventing us from making explicit inference. Although we reveal that the phenotypic state of macrolichens is associated with a higher diversification rate than microlichens, we also show that the evolution of macrolichens predated the K-Pg event. Furthermore, the association between macrolichens and increased diversification is not universal and can be explained, in part, by phylogenetic relatedness. By investigating the macroevolutionary dynamics of lichen-forming fungi our study provides a new empirical system suitable to test the effect of major historical event on shaping biodiversity patterns and to investigate why changes in biodiversity patterns are not in concordance across clades. Our results imply that multiple historical events during the transition from Mesozoic to Cenozoic eras, including the K-Pg mass extinction event, impacted the evolutionary dynamics in lichen-forming fungi. However, future studies focusing on individual lichen-forming fungal families are required to ascertain whether diversification rates are associated with growth form and certain geological events.
URL: https://www.nature.com/articles/s41598-019-44881-1
[Edit/Delete] [Upload PDF/URL]
Abstract: Renewed interests in macroevolutionary dynamics have led to the proliferation of studies on diversification processes in large taxonomic groups, such as angiosperms, mammals, and birds. However, such a study has yet to be conducted in lichenized fungi – an extremely successful and diverse group of fungi. Analysing the most comprehensive time-calibrated phylogenies with a new analytical method, we illustrated drastically different diversification dynamics between two hyper-diverse families of lichenized fungi, Graphidaceae and Parmeliaceae, which represent more than a fourth of the total species diversity of lichenized fungi. Despite adopting a similar nutrition mode and having a similar number of species, Graphidaceae exhibited a lower speciation rate, while Parmeliaceae showed a sharp increase in speciation rate that corresponded with the aridification during the Oligocene-Miocene transition, suggesting their adaptive radiation into a novel arid habitat.
Genera/Families: Graphidaceae/Parmeliaceae
URL: http://www.nature.com/articles/srep10028
[Edit/Delete] [Upload PDF/URL]
Abstract: Taxonomic ranks above the species level are inherently arbitrary. However, there is a growing number of publications aimed at more consistent classifications with comparable ranks among taxa. For this study, we use a recently developed temporal approach that utilizes time-calibrated chronograms to identify and define temporal bands for comparable ordinal and family ranks in Lecanoromycetes, the most diverse lineage of lichen-forming fungi. A multi-locus dataset consisting of 539 taxa in the two major subclasses of Lecanoromycetes, Lecanoromycetidae and Ostropomycetidae, was used to address the circumscription of families and orders. Based on the temporal banding approach, clades that share a common ancestor between 176 and 194 Mya and a time window of 111–135 Mya correspond to order-level and family-level, respectively. Most currently accepted orders and families were supported in their current circumscription, but some new taxa are described. Here we propose a revised, temporally based classification for the two subclasses. Specifically, three new orders are proposed: Sporastatiales, Schaereriales and Thelenellales. Arctomiales, Hymeneliales and Trapeliales are synonymized with Baeomycetales. Varicellariaceae are proposed as a new family, and Diploschistaceae and Thelotremataceae are resurrected. Squamarinaceae and Stereocaulaceae are synonymized with Cladoniaceae, Carbonicolaceae are synonymized with Lecanoraceae, Letrouitiaceae are synonymized with Brigantiaeaceae, Lobariaceae and Nephromataceae are synonymized with Peltigeraceae, Thrombiaceae are synonymized with Protothelenellaceae, and Miltideaceae are synonymized with Agyriaceae. This study represents an important step towards more consistent, comparable deeper-level taxonomic rankings in the most diverse lineages of lichen-forming fungi.
Notes: New: Schaereriales Lumbsch & Leavitt (type: Schaereriaceae M.Choisy ex Hafellner), Sporastatiales Lumbsch & Leavitt (type: Sporastatiaceae Bendiksby & Timdal), Varicellariaceae B.P.Hodk., R.C.Harris & Lendemer ex Lumbsch & Leavitt (type: Varicellaria Nyl.), Thelenellales Lumbsch & Leavitt (type: Thelenellaceae O.E.Erikss. ex H.Mayrhofer). Arctomiales S. Stenroos, Miadl. & Lutzoni, Hymeneliales S.Stenroos, Miadl. & Lutzoni and Trapeliales B.P.Hodk. & Lendemer synonymized with Baeomycetales Lumbsch, Huhndorf & Lutzoni. Carbonicolaceae Bendiksby & Timdal synonymized with Lecanoraceae Körb. Letrouitiaceae Hafellner & Bellem. synonymized with Brigantiaeaceae Hafellner & Bellem. Lobariaceae Chevall. and Nephromataceae Wetmore ex J.C.David & D.Hawksw. synonymized with Peltigeraceae Dumort. Miltideaceae Hafellner synonymized with Agyriaceae Corda. Squamarinaceae Hafellner & Stereocaulaceae Chevall. synonymized with Cladoniaceae Zenker. Thrombiaceae Poelt & Vězda ex J.C.David & D.Hawksw. synonymized with Protothelenellaceae Vězda, H.Mayrhofer & Poelt.
URL: https://academic.oup.com/botlinnean/advance-article-abstract/doi/10.1093/botlinnean/boy060/5091569?redirectedFrom=fulltext
[Edit/Delete]
[Upload PDF/URL]
Keywords: Crustose lichens/ General mixed Yule-coalescent method/ Species delimitation/ Species trees/ Taxonomy
Abstract: Graphis scripta, or script lichen, is a well-known species of crustose lichenized fungi, widely distributed in the temperate region of the Northern Hemisphere. It is now considered to be a species complex, but because of the lack of secondary chemistry and paucity of measurable morphological characters, species delimitation within the complex has been challenging and is thus far based on apothecium and ascospore morphology. In this study, we employed molecular as well as morphological data to assess phylogenetic structure and delimitation of lineages within the G. scripta complex. We generated sequences for four genetic markers (mtSSU, nuLSU, RPB2, and EF-1) and performed phylogenetic analyses. The resulting trees were used to determine the number of distinct lineages by applying a general mixed Yule-coalescent (GMYC) model and species tree estimation through maximum likelihood (STEM). Our analyses suggest between six and seven putative species within the G. scripta complex. However, these did not correspond to the taxa that were recently distinguished based on apothecium morphology and could not be circumscribed with the morphological characters that were traditionally used in the classification of the complex. Any formal taxonomic treatment will require additional sampling and evaluation of additional traits that potentially can characterize these clades.
Genera/Families: Graphis/Graphidaceae
Notes: Molecular data show Graphis scripta is a complex of cryptic species whose delimitation does not match the morphological concepts recently proposed by Neuwirth & Aptroot (2011) for the group in Europe.
URL: http://link.springer.com/article/10.1007%2Fs13127-015-0219-5
[Edit/Delete] [Upload PDF/URL]
Abstract: Based on separately obtained and analyzed molecular data and within the framework of a global revision of the family Trypetheliaceae, 21 new species are described, from the Neotropics and tropical Asia, in the genera Architrypethelium (1), Astrothelium (15), Bathelium (1), Nigrovothelium (1), Trypethelium (1), and Viridothelium (2), namely: Architrypethelium lauropaluanum Lücking, M. P. Nelsen & Marcelli sp. nov., differing from A. hyalinum in the perithecia immersed between coarse thallus verrucae and in the additional ascospore septa; Astrothelium aurantiacocinereum Lücking, Naksuwankul & Lumbsch sp. nov., differing from A. aeneum in the prominent, well-delimited, trypethelioid pseudostromata and the absence of pigment on the thallus surface, as well as in the barely lichenized thallus; A. carassense Lücking, M. P. Nelsen & Marcelli sp. nov., differing from A. purpurascens in orange, K+ red pseudostroma pigment and the slightly larger ascospores; A. cryptolucens Lücking, M. P. Nelsen & N. Salazar sp. nov., differing from A. carrascoense in the inspersed hymenium; A. fijiense Lücking, Naksuwankul & Lumbsch sp. nov., differing from A. cinereorosellum in the presence of lichexanthone on the well-delimited pseudostromata and in the slightly shorter ascospores; A. laevithallinum Lücking, M. P. Nelsen & Marcelli sp. nov., differing from A. endochryseum in the smooth thallus; A. leucosessile Lücking, M. P. Nelsen & Aptroot sp. nov., differing from A. phlyctaena in the conspicuous, sessile pseudostromata; A. macrostomoides Lücking, M. P. Nelsen & Benatti sp. nov., differing from A. macrostomum in the larger ascospores; A. megacrypticum Lücking, M. P. Nelsen & N. Salazar sp. nov., differing from A. longisporum in the single-spored asci and larger ascospores; A. nicaraguense Lücking, M. P. Nelsen & T. Orozco sp. nov., differing from A. gigantosporum in the smaller ascospores; A. norisianum Lücking, M. P. Nelsen & Aptroot sp. nov., differing from A. sepultum in the distinct, well-delimited pseudostromata; A. obtectum Lücking, M. P. Nelsen & Benatti sp. nov., differing from A. nigrocacuminum in the smaller ascospores; A. sordithecium Lücking, M. P. Nelsen & Marcelli sp. nov., differing from A. leucothelium in the inspersed hymenium and the absence of lichexanthone from the thallus surface outside the pseudostromata; A. subendochryseum Lücking, M. P. Nelsen & Marcelli sp. nov., differing from A. endochryseum in the absence of pigment in the pseudostromata and the lateral thallus cover of the pseudostromata; A. subinterjectum Lücking, M. P. Nelsen & Jungbluth sp. nov., differing from A. obtectum in the smaller pseudostromata and smaller ascospores, and from A. interjectum in the diffuse pseudostromata and smaller ascospores; Bathelium porinosporum Lücking, M. P. Nelsen & Gueidan sp. nov., differing from other Bathelium species in the 3-septate, euseptate ascospores; Nigrovothelium bullatum Lücking, Upreti & Lumbsch sp. nov., differing from N. tropicum in the bullate thallus; Trypethelium tolimense Lücking, Moncada & M. Gut. sp. nov., differing from T. xanthoplatystomum in the absence of a yellow-orange pigment on the pseudostromata and the K+ yellow (not K+ red) medullary pigment; Viridothelium tricolor Lücking, M. P. Nelsen & N. Salazar sp. nov., characterized by black perithecia with a lateral ostiole immersed in white pseudostromata strongly contrasting with the surrounding brown thallus, in combination with 2-spored asci and large, muriform ascospores; and V. vonkonratii Lücking, Naksuwankul & Lumbsch sp. nov., differing from V. virens in larger ascospores and mostly solitary ascomata. All species are illustrated and their taxonomy and phylogenetic relationships are discussed. ITS barcoding sequences are reported for five specimens of Bathelium porinosporum.
Notes: New: Architrypethelium lauropaluanum Lücking, M.P.Nelsen & Marcelli (from Brazil and Peru), Astrothelium aurantiacocinereum Lücking, Naksuwankul & Lumbsch (from New Caledonia), As. carassense Lücking, M.P.Nelsen & Marcelli (from Brail), As. cryptolucens Lücking, M.P.Nelsen & N.Salazar (from Panama), As. fijiense Lücking, Naksuwankul & Lumbsch (from Fiji), As. laevithallinum Lücking, M.P.Nelsen & Marcelli (from Brazil), As. leucosessile Lücking, M.P.Nelsen & Aptroot (from Brazil, Panama and Peru), As. macrostomoides Lücking, M.P.Nelsen & Benatti (from Brazil), As. megacrypticum Lücking, M.P.Nelsen & N.Salazar (from Panama), As. nicaraguense Lücking, M.P.Nelsen & T.Orozco (from Nicaragua), As. norisianum Lücking, M.P.Nelsen & Aptroot (from Panama, Peru and Venezuela), As. obtectum Lücking, M.P.Nelsen & Benatti (from Brazil), As. sordithecium Lücking, M.P.Nelsen & Marcelli (from Brazil), As. subendochryseum Lücking, M.P.Nelsen & Marcelli (from Brazil and El Salvador), As. subinterjectum Lücking, M.P.Nelsen & Jungbluth (from Brazil), Bathelium porinosporum Lücking, M.P.Nelsen & Gueidan (from Vietnam), Nigrovothelium bullatum Lücking, Upreti & Lumbsch (from India), Trypethelium tolimense Lücking, Moncada & M.Gut. (from Colombia), Viridothelium tricolor Lücking, M.P.Nelsen & N. Salazar (from Panama and Venezuela), and V. vonkonratii Lücking, Naksuwankul & Lumbsch (from Fiji).
URL: https://www.cambridge.org/core/journals/lichenologist/article/div-classtitlea-pot-pourri-of-new-species-of-span-classitalictrypetheliaceaespan-resulting-from-molecular-phylogenetic-studiesdiv/AF581371E1DA7022485F77C2C8126FAD
[Edit/Delete] [Upload PDF/URL]
Keywords: co-evolution;ecology;ecoregion;mycobiont;photobiont;Trebouxia
Abstract: Microbial symbionts are instrumental to the ecological and long-term evolutionary success of their hosts, and the central role of symbiotic interactions is increasingly recognized across the vast majority of life. Lichens provide an iconic group for investigating patterns in species interactions; however, relationships among lichen symbionts are often masked by uncertain species boundaries or an inability to reliably identify symbionts. The species-rich lichen-forming fungal family Parmeliaceae provides a diverse group for assessing patterns of interactions of algal symbionts, and our study addresses patterns of lichen symbiont interactions at the largest geographic and taxonomic scales attempted to date. We analysed a total of 2356 algal internal transcribed spacer (ITS) region sequences collected from lichens representing ten mycobiont genera in Parmeliaceae, two genera in Lecanoraceae and 26 cultured Trebouxia strains. Algal ITS sequences were grouped into operational taxonomic units (OTUs); we attempted to validate the evolutionary independence of a subset of the inferred OTUs using chloroplast and mitochondrial loci. We explored the patterns of symbiont interactions in these lichens based on ecogeographic distributions and mycobiont taxonomy. We found high levels of undescribed diversity in Trebouxia, broad distributions across distinct ecoregions for many photobiont OTUs and varying levels of mycobiont selectivity and specificity towards the photobiont. Based on these results, we conclude that fungal specificity and selectivity for algal partners play a major role in determining lichen partnerships, potentially superseding ecology, at least at the ecogeographic scale investigated here. To facilitate effective communication and consistency across future studies, we propose a provisional naming system for Trebouxia photobionts and provide representative sequences for each OTU circumscribed in this study.
URL: http://onlinelibrary.wiley.com/doi/10.1111/mec.13271/abstract
[Edit/Delete] [Upload PDF/URL]
Keywords: Ecoregion/ Lecanoraceae/ Selectivity/ Specificity/ Symbiosis/ Trebouxia
Abstract: Identifying factors that influence species interactions is central to research in symbiotic systems. While lichens represent iconic models of symbiosis and play important roles in understanding the biology of symbiotic interactions, patterns of interactions in lichen symbionts and mechanisms governing these relationships are not well characterized. This is due, in part to the fact that current taxonomic approaches for recognizing diversity in lichen symbionts commonly fail to accurately reflect actual species diversity. In this study, we employed DNA-based approaches to circumscribed candidate species-level lineages in rock-posy lichen symbionts (mycobiont = Rhizoplaca species; photobiont = Trebouxia species). Our results revealed a high degree of cryptic diversity in both the myco- and photobionts in these lichens. Using the candidate species circumscribed here, we investigated the specificity of the symbionts toward their partners and inferred the relative importance of various factors influencing symbiont interactions. Distinct mycobiont species complexes, ecozones, and biomes are significantly correlated with the occurrence of photobiont OTUs, indicating that complex interactions among mycobiont lineages, ecogeography, and microhabitat determine interactions between photobionts and their mycobionts in lichen symbiosis. One-to-one specificity between mycobiont and photobiont species was not found, with the exception of R. maheui that associated with a single Trebouxia OTU that was not found with other Rhizoplaca species. We estimated the most recent common ancestor of the core Rhizoplaca group at c. 62.5 Ma, similar in age to the diverse parmelioid core group in Parmeliaceae. However, in contrast to Parmeliaceae, species in Rhizoplaca were found to associate with a narrow range of photobionts. Our study provides important perspectives into species diversity and interactions in iconic lichen symbiotic systems and establishes a valuable framework for continuing research into rock-posy lichens.
URL: http://www.sciencedirect.com/science/article/pii/S1055790316300227
[Edit/Delete] [Upload PDF/URL]
Abstract: Multiple drivers shape the spatial distribution of species, including dispersal capacity, niche incumbency, climate variability, orographic barriers, and plate tectonics. However, biogeographic patterns of fungi commonly do not fit conventional expectations based on studies of animals and plants. Fungi, in general, are known to occur across exceedingly broad, intercontinental distributions, including some important components of biological soil crust communities (BSCs). However, molecular data often reveal unexpected biogeographic patterns in lichenized fungal species that are assumed to have cosmopolitan distributions. The lichen-forming fungal species Psora decipiens is found on all continents, except Antarctica and occurs in BSCs across diverse habitats, ranging from hot, arid deserts to alpine habitats. In order to better understand factors that shape population structure in cosmopolitan lichen-forming fungal species, we investigated biogeographic patterns in the cosmopolitan taxon P. decipiens, along with the closely related taxa P. crenata and P. saviczii. We generated a multi-locus sequence dataset based on a worldwide sampling of these taxa in order to reconstruct evolutionary relationships and explore phylogeographic patterns. Both P. crenata and P. decipiens were not recovered as monophyletic; and P. saviczii specimens were recovered as a monophyletic clade closely related to a number of lineages comprised of specimens representing P. decipiens. Striking phylogeographic patterns were observed for P. crenata, with populations from distinct geographic regions belonging to well-separated, monophyletic lineages. South African populations of P. crenata were further divided into well-supported sub-clades. While well-supported phylogenetic substructure was also observed for the nominal taxon P. decipiens, nearly all lineages were comprised of specimens collected from intercontinental populations. However, all Australian specimens representing P. decipiens were recovered within a single well-supported monophyletic clade consisting solely of Australian samples. Our study supports up to 10 candidate species-level lineages in P. decipiens, based on genealogical concordance and coalescent-based species delimitation analyses. Our results support the general pattern of the biogeographic isolation of lichen-forming fungal populations in Australia, even in cases where closely related congeners have documented intercontinental distributions. Our study has important implications for understanding factors influencing diversification and distributions of lichens associated with BSC.
URL: https://www.frontiersin.org/articles/10.3389/fmicb.2018.00283/full
[Edit/Delete] [Upload PDF/URL]
Abstract: Species in the fungal genus Sticta form symbiotic associations primarily with either green algae or cyanobacteria, but tripartite associations or photosymbiodemes involving both types of photobionts occur in some species. Sticta is known to associate with green algae in the genus Symbiochloris. However, previous studies have shown that algae from other genera, such as Heveochlorella, may also be suitable partners for Sticta. We examined the diversity of green algal partners in the genus Sticta and assessed the patterns of association between the host fungus and its algal symbiont. We used multi-locus sequence data from multiple individuals collected in Australia, Cuba, Madagascar, Mauritius, New Zealand, Reunion and South America to infer phylogenies for fungal and algal partners and performed tests of congruence to assess coevolution between the partners. In addition, event-based methods were implemented to examine which cophylogenetic processes have led to the observed association patterns in Sticta and its green algal symbionts. Our results show that in addition to Symbiochloris, Sticta associates with green algae from the genera Chloroidium, Coccomyxa, Elliptochloris and Heveochlorella, the latter being the most common algal symbiont associated with Sticta in this study. Geography plays a strong role in shaping fungal-algal association patterns in Sticta as mycobionts associate with different algal lineages in different geographic locations. While fungal and algal phylogenies were mostly congruent, event-based methods did not find any evidence for cospeciation between the partners. Instead, the association patterns observed in Sticta and associated algae, were largely explained by other cophylogenetic events such as host-switches, losses of symbiont and failure of the symbiont to diverge with its host. Our results also show that tripartite associations with green algae evolved multiple times in Sticta.
URL: https://www.sciencedirect.com/science/article/abs/pii/S1055790320301329?via%3Dihub
[Edit/Delete] [Upload PDF/URL]
Keywords: lichens/ molecular phylogeny/ South-East Asia/ species delimitation/ Trypetheliaceae
Abstract: The diversity of the Trypethelium eluteriae group in Thailand was studied using molecular (ITS and mtSSU rDNA sequences), morphological, and chemical data. Three species were recognized, T. eluteriae, T. platystomum, and T. subeluteriae, with the latter two being new records for Thailand. The separation of the three species, which have sometimes been regarded as synonymous, is supported by molecular and phenotypic characters. The chemical profiles of the three species are distinct, while ascospore size, often used to distinguish species in the group, shows some overlap.
Countries/Continents: Asia/Thailand
URL: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10075945&fulltextType=RA&fileId=S0024282915000444
[Edit/Delete] [Upload PDF/URL]
Abstract: We provide an expanded and updated, 2-locus phylogeny (mtSSU, nuLSU) of the lichenized fungal family Trypetheliaceae, with a total of 196 ingroup OTUs, in order to further refine generic delimitations and species concepts in this family. As a result, the following 15 clades are recognized as separate genera, including five newly established genera: Aptrootia, Architrypethelium, Astrothelium (including the bulk of corticate species with astrothelioid ascospores; synonyms: Campylothelium, Cryptothelium, Laurera), Bathelium s. str. (excluding B. degenerans and relatives which fall into Astrothelium), the reinstated Bogoriella (for tropical, lichenized species previously placed in Mycomicrothelia), Constrictolumina gen. nov. (for tropical, lichenized species of Arthopyrenia), Dictyomeridium gen. nov. (for a subgroup of species with muriform ascospores previously placed in Polymeridium), Julella (provisionally, as the type species remains unsequenced), Marcelaria (Laurera purpurina complex), Nigrovothelium gen. nov. (for the Trypethelium tropicum group), Novomicrothelia gen. nov. (for an additional species previously placed in Mycomicrothelia), Polymeridium s. str., Pseudopyrenula, Trypethelium s. str. (T. eluteriae group), and Viridothelium gen. nov. (for the Trypethelium virens group). All recognized genera are phenotypically characterized and a discussion on the evolution of phenotypic features in the family is given. Based on the obtained phylogeny, species delimitations are revised and the importance of characters such as thallus morphology, hymenial inspersion, and secondary chemistry for taxonomic purposes is discussed, resulting in a refined species concept.
Notes: New: Constrictolumina Lücking, M. P. Nelsen & Aptroot (type C. cinchonae), C. cinchonae (Ach.) Lücking, M. P. Nelsen (≡ Verrucaria cinchonae Ach.), C. planorbis (Ach.) Lücking, M. P. Nelsen & Aptroot (≡ Verrucaria planorbis Ach.), Dictyomeridium Aptroot, M. P. Nelsen & Lücking (type D. proponens), Dictyomeridium proponens (Nyl.) Aptroot, M. P. Nelsen & Lücking (≡ Verrucaria proponens Nyl.), Nigrovothelium Lücking, M. P. Nelsen & Aptroot (type N. tropicum), Nigrovothelium tropicum (Ach.) Lücking, M. P. Nelsen & Aptroot (≡ Verrucaria tropica Ach.; lectotypified), Novomicrothelia Aptroot, M. P. Nelsen & Lücking (type N. oleosa), Novomicrothelia oleosa (Aptroot) Aptroot, M. P. Nelsen & Lücking (≡ Mycomicrothelia oleosa Aptroot), Viridothelium Lücking, M. P. Nelsen & Aptroot (type V. virens), Viridothelium virens (Tuck. ex Michener) Lücking, M. P. Nelsen & Aptroot (≡Trypethelium virens Tuck.).
URL: https://www.cambridge.org/core/journals/lichenologist/article/div-classtitlea-phylogenetic-framework-for-reassessing-generic-concepts-and-species-delimitation-in-the-lichenized-family-span-classitalictrypetheliaceaespan-ascomycota-dothideomycetesdiv/6CDE9672F477F6AF3AFF8D50D707965D
[Edit/Delete] [Upload PDF/URL]
Abstract: The MycoBank code of the newly described species Usnea parafloridana was missing. The MycoBank code for the species Usnea parafloridana should read: MB818694. Usnea parafloridana K. Mark, Will-Wolf & Randlane sp. nov.; MycoBank No. MB818694. Type: USA, Wisconsin, Vilas Co., Trout Lake Conifer Swamp State Natural Area; 46.0135° N, -89.6586° W; 27.08.2011, Susan Will-Wolf WW14807: isolates WW_018 (holotype, TU; Fig. 4a, c, e), WW_023 (isotype 1, WIS), WW_013 (isotype 2, F). Morphology: thallus shrubby, up to 3–6 cm long, often with relatively few branches; branching mainly isotomic-dichotomous, divergent; lateral branches not narrowed at point of attachment; basal part distinctly jet black, with few annular cracks; papillae verrucose, numerous on main branches and lesser or absent on lateral branches; fibrils few to numerous; soralia small and punctiform when young, enlarging, becoming close to each other but usually staying delimited when mature, more numerous on terminal branches; isidiomorphs numerous, spinulose, relatively short and thick, both on young and mature soralia; cortex thick (9–15%); medulla thin (10.5–13%), dense, not pigmented; central cord thick (60–73%) and white; apothecia not seen (Fig. 4; colour illustrations in online version). Secondary chemistry: usnic acid in cortex; norstictic acid as a major compound, salazinic acid as an accessory substance (present in most examined specimens) in medulla. Ecology: on branches of Abies balsamea, Larix laricina, Picea mariana, or Pinus strobus in cedar swamp, conifer bog and pine plantation with trees over one-hundred years old. Distribution: currently 15 specimens are known from four localities in Wisconsin, USA. Etymology: the species is morphologically somewhat similar to Usnea subfloridana (both taxa have similar shrubby thalli, black basal parts and delimited soralia with numerous isidiomorphs), which phylogenetically appears conspecific with U. florida. The same root ‘florida’ is used in the epithet of the new taxon to underline this morphological similarity while the prefix ‘para-‘ indicates phylogenetic distinctness of the species from U. florida and U. subfloridana.
URL: http://link.springer.com/article/10.1007/s13127-016-0311-5
[Edit/Delete] [Upload PDF/URL]
Keywords: Lichenized fungi/ Rapid radiation/ Species delimitation/ Species trees/ Taxonomy/ Usnea
Abstract: Recent taxonomic and DNA sequence-based studies in several groups of lichen-forming fungi have revealed incongruence between the morphological and molecule-based circumscriptions of species. While the cosmopolitan genus Usnea is well-known and easily recognized by the yellowish beard-like thallus with central cord, delimitation of many Usnea species is difficult due to the high variation and complexity of diagnostic characters. In this study, we assessed the monophyly of 18 species from section Usnea occurring in North America and Europe, including sorediate and sexually reproducing taxa with both pendent and shrubby thalli. Six nuclear markers (ribosomal internal transcribed spacer (ITS) and intergenic spacer (IGS), and protein-coding beta-tubulin, MCM7, RPB1 and RPB2) were sequenced for 144 samples. All analyzed loci show weak genetic structure and short branch lengths in single-locus topologies, suggesting recent diversification history of the sampled taxa. Concatenated, multi-locus analyses conducted in Bayesian and maximum likelihood frameworks, as well as coalescent-based species delimitation and species tree methods, recover several distinct clades, some represent traditional morphology-based species (Usnea cavernosa, U. praetervisa, U. silesiaca, U. wasmuthii), while others form clusters of two or more species (Usnea florida–U. subfloridana, U. fulvoreagens–U. glabrescens, U. barbata–U. chaetophora–U. dasopoga–U. diplotypus, U. barbata–U. intermedia–U. lapponica–U. substerilis). We propose synonymization of U. substerilis under U. lapponica. The status of several other species within intermixed clusters requires further evaluation with more extensive sampling and the inclusion of more variable markers before taxonomic consequences can be considered. A new species, Usnea parafloridana is described from Wisconsin, USA.
Notes: New: Usnea parafloridana K. Mark, Will-Wolf & Randlane (from U.S.A.). Usnea substerilis Motyka is placed in synonymy with U. lapponica Vain.
URL: http://link.springer.com/article/10.1007%2Fs13127-016-0273-7
[Edit/Delete] [Upload PDF/URL]
Abstract: Lichens provide valuable systems for studying symbiotic interactions. In lichens, these interactions are frequently described in terms of availability, selectivity and specificity of the mycobionts and photobionts towards one another. The lichen-forming, green algal genus Trebouxia Puymaly is among the most widespread photobiont, associating with a broad range of lichen-forming fungi. To date, 29 species have been described, but studies consistently indicate that the vast majority of species-level lineages still lack formal description, and new, previously unrecognized lineages are frequently reported. To reappraise the diversity and the evolutionary relationships of species-level lineages in Trebouxia, we assembled DNA sequence data from over 1600 specimens, compiled from a range of sequences from previously published studies, axenic algal cultures, and lichens collected from poorly sampled regions. From these samples, we selected representatives of the currently known genetic diversity in the lichenized Trebouxia and inferred a phylogeny from multi-locus sequence data (ITS, rbcL, cox2). We demonstrate that the current formally described species woefully underrepresent overall species-level diversity in this important lichen-forming algal genus. We anticipate that an integrative taxonomic approach, incorporating morphological and physiological data from axenic cultures with genetic data, will be required to establish a robust, comprehensive taxonomy for Trebouxia. The data presented here provide an important impetus and reference dataset for more reliably characterizing diversity in lichenized algae and in using lichens to investigate the evolution of symbioses and holobionts.
URL: https://www.sciencedirect.com/science/article/abs/pii/S1055790320300932?via%3Dihub
[Edit/Delete] [Upload PDF/URL]
Abstract: Historic and modern efforts to understand lichen diversity and evolution have overwhelmingly concentrated on that of the fungal partner, which represents one of the most taxonomically diverse nutritional modes among the Fungi. But what about the algal and cyanobacterial symbionts? An explosion of studies on these cryptic symbionts over the past 20+ years has facilitated a richer understanding of their diversity, patterns of association, and the symbiosis itself. In a From the Cover article in this issue of Molecular Ecology, Dal Forno et al. (2021) provide new insight into one of the most fascinating lichen symbioses. By sequencing cyanobacterial symbionts from over 650 specimens, they reveal the presence of overlooked cyanobacterial diversity, evidence for symbiont sharing among distantly related fungi, and utilize a comparative dating framework to reveal temporal discordance among interacting fungal and cyanobacterial lineages.
Notes: Perspective piece on photobiont-mycobiont associations.
URL: https://onlinelibrary.wiley.com/doi/10.1111/mec.15884
[Edit/Delete] [Upload PDF/URL]
Abstract: The early‐successional status of lichens in modern terrestrial ecosystems, together with the role lichen‐mediated weathering plays in the carbon cycle, have contributed to the long and widely held assumption that lichens occupied early terrestrial ecosystems prior to the evolution of vascular plants and drove global change during this time. Their poor preservation potential and the classification of ambiguous fossils as lichens or other fungal–algal associations have further reinforced this view. As unambiguous fossil data are lacking to demonstrate the presence of lichens prior to vascular plants, we utilize an alternate approach to assess their historic presence in early terrestrial ecosystems. Here, we analyze new time‐calibrated phylogenies of ascomycete fungi and chlorophytan algae, that intensively sample lineages with lichen symbionts. Age estimates for several interacting clades show broad congruence and demonstrate that fungal origins of lichenization postdate the earliest tracheophytes. Coupled with the absence of unambiguous fossil data, our work finds no support for lichens having mediated global change during the Neoproterozoic‐early Paleozoic prior to vascular plants. We conclude by discussing our findings in the context of Neoproterozoic‐Paleozoic terrestrial ecosystem evolution and the paleoecological context in which vascular plants evolved.
URL: https://onlinelibrary.wiley.com/doi/full/10.1111/gbi.12369
[Edit/Delete] [Upload PDF/URL]
Abstract: Symbioses are evolutionarily pervasive and play fundamental roles in structuring ecosystems, yet our understanding of their macroevolutionary origins, persistence, and consequences is incomplete. We traced the macroevolutionary history of symbiotic and phenotypic diversification in an iconic symbiosis, lichens. By inferring the most comprehensive time-scaled phylogeny of lichen-forming fungi (LFF) to date (over 3,300 species), we identified shifts among symbiont classes that broadly coincided with the convergent evolution of phylogenetically or functionally similar associations in diverse lineages (plants, fungi, bacteria). While a relatively recent loss of lichenization in Lecanoromycetes was previously identified, our work instead suggests lichenization was abandoned far earlier, interrupting what had previously been considered a direct switch between trebouxiophycean and trentepohlialean algal symbionts. Consequently, some of the most diverse clades of LFF are instead derived from nonlichenized ancestors and re-evolved lichenization with Trentepohliales algae, a clade that also facilitated lichenization in unrelated lineages of LFF. Furthermore, while symbiont identity and symbiotic phenotype influence the ecology and physiology of lichens, they are not correlated with rates of lineage birth and death, suggesting more complex dynamics underly lichen diversification. Finally, diversification patterns of LFF differed from those of wood-rotting and ectomycorrhizal taxa, likely reflecting contrasts in their fundamental biological properties. Together, our work provides a timeline for the ecological contributions of lichens, and reshapes our understanding of symbiotic persistence in a classic model of symbiosis.
URL: https://www.pnas.org/content/early/2020/08/05/2001913117
[Edit/Delete] [Upload PDF/URL]
Keywords: crustose/ foliicolous/ Ostropomycetidae/ perithecia/ systematics/ Thelenellaceae/ tropics
Abstract: The lichen-forming fungal genus Aspidothelium has either been considered to represent a separate genus and family or a synonym of Thelenella in Thelenellaceae. At times, a close relationship has been suggested with genera now placed in Celotheliaceae, Monoblastiaceae, Porinaceae, Protothelenellaceae, Pyrenulaceae, Strigulaceae, Thelenellaceae, and Verrucariaceae, families scattered across three ascomycete classes. Consequently, its classification has remained unstable, and the genus is currently listed as incertae sedis within Ascomycota. Here we utilize DNA sequence data to clarify its position. Our sampling suggests that Aspidothelium is embedded within the family Thelenellaceae (Lecanoromycetes: Ostropomycetidae), supporting previous proposals to synonymize Aspidotheliaceae with Thelenellaceae. This clade is allied with the order Ostropales and further work is needed to elucidate whether it should be considered part of Ostropales or a distinct order. Aspidothelium is monophyletic, and its continued recognition requires acceptance of the genus Chromatochlamys. The abandonment of historic classification schemes resulted in the proliferation of many orphaned clades of perithecial, lichen-forming fungi – the present study has clarified the higher-level relationships of one of these enigmatic families, and facilitated its placement in a modern phylogenetic framework.
URL: http://www.tandfonline.com/doi/full/10.1080/14772000.2016.1203039
[Edit/Delete] [Upload PDF/URL]
Abstract: Lichens are classic models of symbiosis, and one of the most frequent nutritional modes among fungi. The ecologically and geographically widespread lichen-forming algal (LFA) genus Trebouxia is one of the best-studied groups of LFA and associates with over 7000 fungal species. Despite its importance, little is known about its diversification. We synthesized twenty years of publicly-available data by characterizing the ecological preferences of this group and testing for time-variant shifts in climatic regimes over a distribution of trees. We found evidence for limited shifts among regimes, but that disparate lineages convergently evolved similar ecological tolerances. Early Trebouxia lineages were largely forest specialists or habitat generalists that occupied a regime whose extant members occur in moderate climates. Trebouxia then convergently diversified in non-forested habitats and expanded into regimes whose modern representatives occupy wet-warm and cool-dry climates. We rejected models in which climatic diversification slowed through time, suggesting climatic diversification is inconsistent with that expected under an adaptive radiation. In addition, we found that climatic and vegetative regime shifts broadly coincided with the evolution of biomes and associated or similar taxa. Together, our work illustrates how this keystone symbiont from an iconic symbiosis evolved to occupy diverse habitats across the globe.
URL: https://academic.oup.com/femsec/advance-article-abstract/doi/10.1093/femsec/fiab072/6279059?redirectedFrom=fulltext
[Edit/Delete] [Upload PDF/URL]
Abstract: Lichens are widely utilized as indicators of air quality, forest health and climate change. In Central Europe, specific lichens have been designated as climate change indicators; however, the lichen biota of central Europe has been substantially altered by air pollution and only re-established during the past decades—complicating the interpretation of recent changes in lichen composition. To assess their validity as climate change indicators, we aggregated georeferenced records of these taxa and compared their historic and modern distributions. Modern distributions substantially differed for fewer than half of the indicator taxa with sufficient data to enable evaluation—reinforcing their utility as climate change indicators. However, modern distributions for approximately half of the taxa evaluated were largely confined to historically suitable climates—raising questions about their utility as climate change indicators. We were unable to model historic distributions for nearly two-thirds of all indicator taxa due to insufficient data. About one-third of these had multiple modern records but one or fewer historic records, suggesting they may indeed be expanding their range; however, about half had comparable or greater numbers of historic records relative to modern records, complicating their interpretation as climate change indicators. Together, our work illustrates that distributions for fewer than half of the lichen climate change indicators have substantially shifted in the recent past, and calls into question whether the remaining designated taxa are indeed strong positive indicators of climate change. We argue that more quantitative, evidence-based derivations of climate change indicators are required to accurately detect climate change.
URL: https://link.springer.com/article/10.1007/s10531-020-02057-8
[Edit/Delete] [Upload PDF/URL]
Abstract: Foliicolous lichens are formed by diverse, highly specialized fungi that establish themselves and complete their life cycle within the brief duration of their leaf substratum. Over half of these lichen-forming fungi are members of either the Gomphillaceae or Pilocarpaceae, and associate with Trebouxia-like green algae whose identities have never been positively determined. We investigated the phylogenetic affinities of these photobionts to better understand their role in lichen establishment on an ephemeral surface. Thallus samples of Gomphillaceae and Pilocarpaceae were collected from foliicolous communities in southwest Florida and processed for sequencing of photobiont marker genes, algal cultivation and/or TEM. Additional specimens from these families and also from Aspidothelium (Thelenellaceae) were collected from a variety of substrates globally. Sequences from rbcL and nuSSU regions were obtained and subjected to Maximum Likelihood and Bayesian analyses. Analysis of 37 rbcL and 7 nuSSU algal sequences placed all photobionts studied within the provisional trebouxiophycean assemblage known as the Watanabea clade. All but three of the sequences showed affinities within Heveochlorella, a genus recently described from tree trunks in East Asia. The photobiont chloroplast showed multiple thylakoid stacks penetrating the pyrenoid centripetally as tubules lined with pyrenoglobuli, similar to the two described species of Heveochlorella. We conclude that Heveochlorella includes algae of potentially major importance as lichen photobionts, particularly within (but not limited to) foliicolous communities in tropical and subtropical regions worldwide. The ease with which they may be cultivated on minimal media suggests their potential to thrive free-living as well as in lichen symbiosis.
URL: http://onlinelibrary.wiley.com/doi/10.1111/jpy.12446/abstract
[Edit/Delete] [Upload PDF/URL]
Abstract: Lichen-based indices were developed for monitoring local climate and air quality impacts in the United States of America (U.S.A.) Mid-Atlantic states (MidA). The U.S.A. Forest Service Forest Inventory and Analysis Program (FIA) uses such biological indicators to monitor forest environments. Index development used a unique combination of recommended analysis techniques. The Climate Index (Axis 1 of nonmetric multidimensional scaling [NMS] ordination of 189 plots, 80 lichen species) accounted for 44.7% of data variation, and was correlated with latitude, temperature and humidity (r2 = 0.5 to 0.7). The Pollution Index was based on abundances of 10 tolerant and 27 sensitive lichen species selected from Indicator Species Analysis and other techniques (210 plots, 180 species). Strong quantitative support guided careful selection of pollution indicator species. The Pollution Index was strongly correlated with Al, Cu, Fe, N and S measured in lichen samples (51 plots; maximum r2=0.796), and with 51-plot NMS Axis 1 (r2=0.694; 41.7% of information) correlated with pollution. Indices were uncorrelated with each other or with nearby forest cover, another important factor. From within-site repeatability, Climate Index changes of 13–21% of full range and Pollution Index changes of 18–24% will be detectable. These indices fill a gap to complete FIA index coverage for much of eastern U.S.A. Both indices are suitable for application in other MidA studies. Comparisons with similar FIA studies supported guidelines for use of our indicator selection process and evaluation of environmental interactions to improve other studies.
Countries/Continents: U.S.A./North America
URL: http://www.bioone.org/doi/abs/10.1639/0007-2745-121.4.461
[Edit/Delete] [Upload PDF/URL]
Keywords: Air quality/ bioindicator/ eastern U.S.A./ Flavoparmelia caperata/ forest cover/ air pollution/ Punctelia rudecta
Abstract: Element analysis was conducted on naturally-growing Flavoparmelia caperata (L.) Hale and Punctelia rudecta (Ach.) Krog (26 sites) in 2003–05 for a 30-year resurvey of forest lichen communities near a power plant in Wisconsin. Cu, Cr, N, and S increased strongly with power plant impact (66 samples, both species) and are good candidate bioindicators for local pollution; Al and Fe increased weakly and are not recommended. Hg is a candidate pollution indicator from comparison with a background site (only F. caperata data: 39 samples, 23 sites). Only N and S were correlated with lichen species abundance and are thus candidate bioindicators for lichen response. Abundance of P. rudecta was lower and that of Phaeophyscia pusilloides (Zahlbr.) Essl. was higher with more N or S in lichens; abundances of F. caperata and large foliose species as a group were lower with higher modeled SO2 from the power plant (no response from four other tested lichen species or groups). Sites in more forested landscapes to the west of the power plant had more lichen species, including disturbance-sensitive taxa. Heathier lichens there may have led to higher concentrations of Al, Cr, and S, plus Li (only F. caperata data). Univariate general linear modeling (GLM) was more useful than regression to test species effect at 7 sites. Element analysis confirmed earlier records of minimal power plant impact on lichens in this area, where no truly pollution-sensitive lichen species have been recorded for decades.
URL: http://www.bioone.org/doi/abs/10.1639/0007-2745-118.4.371
[Edit/Delete] [Upload PDF/URL]
Number of hits shown/total: 24/24.
Number of records in database: 53517.
Current date: 2024.04.24.OK