Examinando por Autor "Wedin, Mats"

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Crittendenia gen. nov., a new lichenicolous lineage in the Agaricostilbomycetes (Pucciniomycotina), and a review of the biology, phylogeny and classification of lichenicolous heterobasidiomycetes
(Cambridge University Press, 2021-03-12) Millanes, Ana M; Diederich, Paul; Westberg, Martin; Wedin, Mats
The lichenicolous ‘heterobasidiomycetes’ belong in the Tremellomycetes (Agaricomycotina) and in the Pucciniomycotina. In this paper, we provide an introduction and review of these lichenicolous taxa, focusing on recent studies and novelties of their classification, phylogeny and evolution. Lichen-inhabiting fungi in the Pucciniomycotina are represented by only a small number of species included in the genera Chionosphaera, Cyphobasidium and Lichenozyma. The phylogenetic position of the lichenicolous representatives of Chionosphaera has, however, never been investigated by molecular methods. Phylogenetic analyses using the nuclear SSU, ITS, and LSU ribosomal DNA markers reveal that the lichenicolous members of Chionosphaera form a monophyletic group in the Pucciniomycotina, distinct from Chionosphaera and outside the Chionosphaeraceae. The new genus Crittendenia is described to accommodate these lichen-inhabiting species. Crittendenia is characterized by minute synnemata-like basidiomata, the presence of clamp connections and aseptate tubular basidia from which 4–7 spores discharge passively, often in groups. Crittendenia, Cyphobasidium and Lichenozyma are the only lichenicolous lineages known so far in the Pucciniomycotina, whereas Chionosphaera does not include any lichenicolous taxa.
Five new species in the Tremella caloplacae complex
(Cambridge University Press, 2023) Freire-Rallo, Sandra; Diederich, Paul; Millanes, Ana María; Wedin, Mats
Tremella caloplacae (Zahlbr.) Diederich is a species complex including at least nine different species. Here, we formally describe the new species Tremella elegantis, T. nimisiana, T. parietinae, T. pusillae and T. sorediatae. Tremella elegantis induces galls in the hymenium of Rusavskia elegans and forms 2-celled basidia, where cells rarely elongate and sometimes give the appearance of two immature, independent basidia. Tremella nimisiana has small basidiomata (less than 1 mm diam.), narrowly ellipsoid to pyriform 2-celled, occasionally clavate to subcylindrical 3-celled basidia, and grows in the hymenium of Xanthocarpia species. Tremella parietinae is characterized by the exclusive growth in the hymenium of Xanthoria parietina, the broadly fusiform to ellipsoid probasidia, and the subspherical, pyriform or ellipsoid 2(–3)-celled basidia. Tremella pusillae has ellipsoidal probasidia, 2(–3)-celled pyriform or ellipsoidal basidia that sometimes are constricted at the septum, and grows only on Calogaya pusilla. Tremella sorediatae is characterized by inducing galls on the thallus of Rusavskia sorediata and by pyriform to ellipsoid basidia that sometimes are constricted at the septum. Three species are not formally described and are left unnamed as Tremella sp. 13 on Calogaya biatorina, Tremella sp. 14 on Calogaya decipiens and Tremella sp. 15 on Polycauliona sp. Tremella caloplacae in the strict sense is re-circumscribed as a species confined to Variospora species.
Flora of Lichenicolous Fungi, Vol. 1, Basidiomycota
(National Museum of Natural History, Luxembourg, 2022-08-20) Diederich, Paul; Millanes, Ana María; Wedin, Mats; Lawrey, James D
This first volume of a worldwide Flora of Lichenicolous Fungi deals with the Basidiomycota. A total of 197 species are accepted, described, illustrated and keyed out, and 13 additional species are shortly introduced but not formally described. They belong to the Agaricomycetes (4 species in 2 genera of Agaricales, 2 – 1 Atheliales, 1 – 1 Boletales, 11 – 8 Cantharellales, 12 – 5 Corticiales) and the Tremellomycetes (8 – 1 Filobasidiales, 129 – 3 Tremellales) in the Agaricomycotina, and to the Agaricostilbomycetes (18 – 1 Agaricostilbales), Cystobasidiomycetes (9 – 1 Cyphobasidiales) and Microbotryomycetes (1 – 1 Kriegeriaceae) in the Pucciniomycotina, while 2 species incertae sedis are provisionally treated in ‘Syzygospora’. The species of Agaricomycetes belong to the informal group of homobasidiomycetes and are mainly generalists, while the species of Tremellomycetes, Agaricostilbomycetes, Cystobasidiomycetes, Microbotryomycetes and ‘Syzygospora’ belong to the heterobasidiomycetes and are all host-specific. Three new genera, 74 new species, 1 new subspecies, and 3 new combinations are introduced. Phylogenetic trees are given for each taxonomic group, some being obtained from previous papers, while most are based on new phylogenetic results, based on hundreds of new DNA sequences obtained during the preparation of this volume. The former Biatoropsis usnearum, Syzygospora physciacearum, Tremella parmeliarum and T. pertusariae are regarded as species complexes, including many newly described species, while some other species complexes, especially Cyphobasidium hypotrachynicola, C. usneicola, Tremella caloplacae, T. lobariacearum and T. ramalinae need further studies. Six new species of Biatoropsis or Tremella have basidia producing conidia instead of basidiospores, one new Tremella species has deciduous epibasidia acting as diaspores, and four new asexual taxa of Tremella have a layer of conidiogenous cells producing clamped conidia. Six types of host-specific galls resembling Tremella basidiomata, but probably induced by bacteria, are briefly described and included in the host-based key.
Phylogeny, evolution and a re-classification of the Lichinomycetes
(Westerdijk Fungal Biodiversity Institute, 2024-12) Prieto, Maria; Wedin, Mats; Schultz, Matthias
The Lichinomycetes is an independent lichenized lineage within the Ascomycota comprising ca. 390 species and 50 genera. Very few studies have dealt with family and genus classification using molecular data and many groups are in need of thorough revision. Thus, we constructed a multilocus phylogeny (mtSSU, RPB2 and mcm7 gene regions) including 190 specimens of Lichinomycetes belonging to 126 species. Ancestral state reconstruction analyses were carried out to trace the evolution of selected characters. The current classification scheme of the Lichinomycetes based on morphological and anatomical characters is in great conflict with the phylogenetic relationships resulting from the present study. The results suggest substantial non-monophyly at the family and genus levels. A revised classification is proposed here and an overview of genera accepted in the Lichinomycetes is given. Ancestral Lichinomycetes are reconstructed as crustose with pycnoascocarps and octosporous asci. We used a combination of characters to delineate groups including the ascoma development and the type of asci. The revised classification includes 11 new genera, five resurrected genera, and 54 new combinations distributed in four families (three emended and one new). Three new species are also described.
Species diversity of basidiomycota
(Springer, 2022-01-14) He, Mao‑Qiang; Zhao, Rui‑Lin; Liu, Dong‑Mei; Denchev, Teodor T.; Begerow, Dominik; Yurkov, Andrey; Kemler, Martin; Millanes, Ana M.; Wedin, Mats; McTaggart, AR; Shivas, Roger G.; Buyck, Bart; Chen, Jie; Vizzini, Alfredo; Papp, Viktor; Zmitrovich, Ivan V.; Davoodian, Naveed; Hyde, Kevin D.
Fungi are eukaryotes that play essential roles in ecosystems. Among fungi, Basidiomycota is one of the major phyla with more than 40,000 described species. We review species diversity of Basidiomycota from five groups with different lifestyles or habitats: saprobic in grass/forest litter, wood-decaying, yeast-like, ectomycorrhizal, and plant parasitic. Case studies of Agaricus, Cantharellus, Ganoderma, Gyroporus, Russula, Tricholoma, and groups of lichenicolous yeast-like fungi, rust fungi, and smut fungi are used to determine trends in discovery of biodiversity. In each case study, the number of new species published during 2009–2020 is analysed to determine the rate of discovery. Publication rates differ between taxa and reflect different states of progress for species discovery in different genera. The results showed that lichenicolous yeast-like taxa had the highest publication rate for new species in the past two decades, and it is likely this trend will continue in the next decade. The species discovery rate of plant parasitic basidiomycetes was low in the past ten years, and remained constant in the past 50 years. We also found that the establishment of comprehensive and robust taxonomic systems based on a joint global initiative by mycologists could promote and standardize the recognition of taxa. We estimated that more than 54,000 species of Basidiomycota will be discovered by 2030, and estimate a total of 1.4–4.2 million species of Basidiomycota globally. These numbers illustrate a huge gap between the described and yet unknown diversity in Basidiomycota.
To explore strange new worlds – The diversification in Tremella caloplacae was linked to the adaptive radiation of the Teloschistaceae
(ELSEVIER, 2023-12-23) Freire-Rallo, Sandra; Wedin, Mats; Diederich, Paul; Millanes, Ana María
Lichenicolous fungi are a heterogeneous group of organisms that grow exclusively on lichens, forming obligate associations with them. It has often been assumed that cospeciation has occurred between lichens and lichenicolous fungi, but this has been seldom analysed from a macroevolutionary perspective. Many lichenicolous species are rare or are rarely observed, which results in frequent and large gaps in the knowledge of the diversity of many groups. This, in turn, hampers evolutionary studies that necessarily are based on a reasonable knowledge of this diversity. Tremella caloplacae is a heterobasidiomycete growing on various hosts from the lichen-forming family Teloschistaceae, and evidence suggests that it may represent a species complex. We combine an exhaustive sampling with molecular and ecological data to study species delimitation, cophylogenetic events and temporal concordance of this association. Tremella caloplacae is here shown to include at least six distinct host-specific lineages (=putative species). Host switch is the dominant and most plausible event influencing diversification and explaining the coupled evolutionary history in this system, although cospeciation cannot be discarded. Speciation in T. caloplacae would therefore have occurred coinciding with the rapid diversification – by an adaptive radiation starting in the late Cretaceous – of their hosts. New species in T. caloplacae would have developed as a result of specialization on diversifying lichen hosts that suddenly offered abundant new ecological niches to explore or adapt to.
Tremella macrobasidiata and Tremella variae have abundant and widespread yeast stages in Lecanora lichens
(Applied Microbiology International, 2021-03) Tuovinen, Veera; Millanes, Ana María; Freire-Rallo, Sandra; Rosling, Anna; Wedin, Mats
Dimorphism is a widespread feature of tremellalean fungi in general, but a little-studied aspect of the biology of lichen-associated Tremella. We show that Tremella macrobasidiata and Tremella variae have an abundant and widespread yeast stage in their life cycles that occurs in Lecanora lichens. Their sexual filamentous stage is restricted to a specific lichen: T. macrobasidiata only forms basidiomata on Lecanora chlarotera hymenia and T. variae only on Lecanora varia thalli. However, the yeast stage of T. macrobasidiata is less specific and can occur in L. varia lichens, whilst all life stages of T. variae may be specific to L. varia. Contrary to the hyphal stages, the yeasts are distributed across the thalli and hymenia of Lecanora lichens, and not limited to specimens with basidiomata. Tremella macrobasidiata was present in all studied L. chlarotera, and in 59% of L. varia specimens. Only in 8% of the L. varia thalli could none of the two Tremella species be detected. Our results indicate that lichen-associated Tremella may be much more abundant and widespread than previously assumed leading to skewed estimations about their distribution ranges and lichen specificity, and raise new questions about their biology, ecology and function in the symbiosis.