A new species of Sagiolechia (Sagiolechiaceae) from Norway, with lirelliform ascomata and 1-septate ascospores

The new species Sagiolechia monoseptata is described from the northern boreal zone of Norway where it was found on a shaded siliceous rock under a boulder in a north-facing, small, steep scree. It is characterized by the pale greyish-green thallus, black, lirelliform ascomata, and 1-septate ascospores of (11–) 12–16 × (4–) 5–6 (– 7) µm, all features unique within the genus. Despite the unusual combination of morphological characters, phylogenetic analyses using nuLSU, mtSSU and RPB2 sequences place the new lichen in the genus Sagiolechia with full support.publishedVersio

Phylogenetic placement of the lichenicolous, anamorphic genus Lichenodiplis and its connection to Muellerella-like teleomorphs

Lichenicolous fungi are a specialized group of taxa which inhabit lichens and develop diverse degrees of specificity and parasitic behaviour towards their hosts. They are recognized only by their phenotypic symptoms and sexual or asexual spore-producing structures on the lichen thalli. Only recently, molecular data and culture dependent approaches have helped in uncovering the species diversity and in verifying the phylogenetic position and anamorpheteleomorph relationships of some taxa. Here, we studied the phylogenetic placement of representative taxa of two lichenicolous genera, the coelomycete Lichenodiplis and the ascomycete Muellerella. We obtained molecular data for three nuclear and mitochondrial loci (28S, 18S, and 16S), both from fresh collected specimens and culture isolates. Our multilocus phylogeny places Lichenodiplis and Muellerella samples in one monophyletic, fully supported clade, sister to Epibryon (Epibryaceae) in Chaetothyriales (Eurotiomycetes). Morphological analyses of axenically cultured fungi show the formation of conidiomata and conidiospores in both Lichenodiplis and Muellerella isolates. We suggest that the species Lichenodiplis lecanorae and Muellerella atricola represent, respectively, the anamorphic and teleomorphic stages of the same fungus and discuss their relationships with the other fungal families in Chaetothyriomycetidae

muellerella a lichenicolous fungal genus recovered as polyphyletic within chaetothyriomycetidae eurotiomycetes ascomycota

AbstractMolecular data and culture-dependent methods have helped to uncover the phylogenetic relationships of numerous species of lichenicolous fungi, a specialized group of taxa that inhabit lichens and have developed diverse degrees of specificity and parasitic behaviors. The majority of lichenicolous fungal taxa are known in either their anamorphic or teleomorphic states, although their anamorph-teleomorph relationships have been resolved in only a few cases. The pycnidium-forming Lichenodiplis lecanorae and the perithecioid taxa Muellerella atricola and M. lichenicola were recently recovered as monophyletic in Chaetothyriales (Eurotiomycetes). Both genera are lichenicolous on multiple lichen hosts, upon which they show a subtle morphological diversity reflected in the description of 14 species in Muellerella (of which 12 are lichenicolous) and 12 in Lichenodiplis. Here we focus on the teleomorphic genus Muellerella and investigate its monophyly by expanding the taxon sampling to other species occurring on diverse lichen hosts. We generated molecular data for two nuclear and one mitochondrial loci (28S, 18S and 16S) from environmental samples. The present multilocus phylogeny confirms the monophyletic lineage of the teleomorphic M. atricola and M. lichenicola with their L. lecanorae-like anamorphs, but places the rest of the Muellerella species studied in two different monophyletic lineages with strong support. The first, Muellerella spp. 1, is nested within some new lineages of black fungi isolated from different epilithic lichen thalli, while the second, Muellerella spp. 2, is closely related to the Verrucariales. Based on these results, we reappraise the phylogenetic placement of Muellerella and suggest its polyphyly within Chaetothyriomycetidae

Photobiont switching causes changes in the reproduction strategy and phenotypic dimorphism in the Arthoniomycetes

Phylogenetic analyses using mtSSU and nuITS sequences of Buellia violaceofusca (previously placed in Lecanoromycetes), a sterile, sorediate lichen having a trebouxioid photobiont, surprisingly prove that the species is conspecific with Lecanographa amylacea (Arthoniomycetes), a fertile, esorediate species with a trentepohlioid photobiont. These results suggest that L. amylacea and B. violaceofusca are photomorphs of the same mycobiont species, which, depending on the photobiont type, changes the morphology and the reproduction strategy. This is the first example of a lichenized fungus that can select between Trebouxia (Trebouxiophyceae) and trentepohlioid (Ulvophyceae) photobionts. Trebouxia photobionts from the sorediate morphotype belong to at least three different phylogenetic clades, and the results suggest that Lecanographa amylacea can capture the photobiont of other lichens such as Chrysothrix candelaris to form the sorediate morphotype. Phylogenetic analyses based on rbcL DNA data suggest that the trentepohlioid photobiont of L. amylacea is closely related to Trentepohlia isolated from fruticose lichens. The flexibility in the photobiont choice enables L. amylacea to use a larger range of tree hosts. This strategy helps the lichen to withstand changes of environmental conditions, to widen its distribution range and to increase its population size, which is particularly important for the survival of this rare species

Optical structure and function of the white filamentary hair covering the edelweiss bracts

The optical properties of the inflorescence of the high-altitude ''Leontopodium nivale'' subsp. ''alpinum'' (edelweiss) is investigated, in relation with its submicrometer structure, as determined by scanning electron microscopy. The filaments forming the hair layer have been found to exhibit an internal structure which may be one of the few examples of a photonic structure found in a plant. Measurements of light transmission through a self-supported layer of hair pads taken from the bracts supports the idea that the wooly layer covering the plant absorbs near-ultraviolet radiation before it reaches the cellular tissue. Calculations based on a photonic-crystal model provides insight on the way radiation can be absorbed by the filamentary threads.Comment: 9 pages, 13 figures. Published pape

Allons-nous vers une société plus responsable grâce à la pandémie de Covid-19 ?

La question traitée dans cet article porte sur le monde d’après la pandémie... Représente-t-elle un moment décisif qui va nous faire basculer vers une société plus responsable sur les plans sociaux et environnementaux ? De nouvelles habitudes et de nouveaux comportements responsables vont-ils se mettre en place de manière durable ? Pour répondre à ces enjeux, cet article mobilise des théories plurielles associées aux changements d’habitudes. Des préconisations s’adressant autant aux entreprises, qu’aux décideurs publics ou citoyens sont proposées pour dessiner les contours d’un après-Covid-19 socialement et écologiquement plus acceptable