Unravelling the phylogenetic relationships of lichenised fungi in Dothideomyceta

We present a revised phylogeny of lichenised Dothideomyceta (Arthoniomycetes and Dothideomycetes) based on a combined data set of nuclear large subunit (nuLSU) and mitochondrial small subunit (mtSSU) rDNA data. Dothideomyceta is supported as monophyletic with monophyletic classes Arthoniomycetes and Dothideomycetes; the latter, however, lacking support in this study. The phylogeny of lichenised Arthoniomycetes supports the current division into three families: Chrysothrichaceae (Chrysothrix), Arthoniaceae (Arthonia s. l., Cryptothecia, Herpothallon), and Roccellaceae (Chiodecton, Combea, Dendrographa, Dichosporidium, Enterographa, Erythrodecton, Lecanactis, Opegrapha, Roccella, Roccellographa, Schismatomma, Simonyella). The widespread and common Arthonia caesia is strongly supported as a (non-pigmented) member of Chrysothrix. Monoblastiaceae, Strigulaceae, and Trypetheliaceae are recovered as unrelated, monophyletic clades within Dothideomycetes. Also, the genera Arthopyrenia (Arthopyreniaceae) and Cystocoleus and Racodium (Capnodiales) are confirmed as Dothideomycetes but unrelated to each other. Mycomicrothelia is shown to be unrelated to Arthopyrenia s.str., but is supported as a monophyletic clade sister to Trypetheliaceae, which is supported by hamathecium characters. The generic concept in several groups is in need of revision, as indicated by non-monophyly of genera, such as Arthonia, Astrothelium, Cryptothecia, Cryptothelium, Enterographa, Opegrapha, and Trypethelium in our analyses

Diversity and Composition of the Leaf Mycobiome of Beech (Fagus sylvatica) Are Affected by Local Habitat Conditions and Leaf Biochemistry

Comparative investigations of plant-associated fungal communities (mycobiomes) in distinct habitats and under distinct climate regimes have been rarely conducted in the past. Nowadays, high-throughput sequencing allows routine examination of mycobiome responses to environmental changes and results at an unprecedented level of detail. In the present study, we analysed Illumina-generated fungal ITS1 sequences from European beech (Fagus sylvatica) originating from natural habitats at two different altitudes in the German Alps and from a managed tree nursery in northern Germany. In general, leaf-inhabiting mycobiome diversity and composition correlated significantly with the origin of the trees. Under natural condition the mycobiome was more diverse at lower than at higher elevation, whereas fungal diversity was lowest in the artificial habitat of the tree nursery. We further identified significant correlation of leaf chlorophylls and flavonoids with both habitat parameters and mycobiome biodiversity. The present results clearly point towards a pronounced importance of local stand conditions for the structure of beech leaf mycobiomes and for a close interrelation of phyllosphere fungi and leaf physiology

Lias-Fossilien aus der Tongrube Eichenberg, Nordhessen

Fossilreiche Aufschlüsse im Lias des Leinetalgrabens sind eine Seltenheit. Eine Ausnahme hiervon bildet die Tongrube bei Eichenberg an der Grenze von Nordhessen zu Niedersachsen, welche etwa 20 m Ton- und Mergelschiefer des höheren Lias a3 mit einer individuenreichen Ammonoideenfauna (Arnioceras ssp., Euagassiceras resupinatum) erschließt. Die Muschelfauna wird durch eine artenarme Vergesellschaftung von dünnschaligen, vorwiegend epibyssaten Formen repräsentiert, wie sie in schlecht durchlüfteten Sedimentationsräumen des Unterjura typisch is

Ruwenzoria, a new genus of the Xylariaceae from Central Africa

During a foray to the mountain rainforests of the Democratic Republic of the Congo, a peculiar species of Xylariaceae was found, which could not be accommodated in any of the existing genera. It is recognised as representative of a new genus, named Ruwenzoria, owing to the presence of a new combination of teleomorphic and anamorphic characters that are regarded as significant for generic segregation within the Xylariaceae. Studies on its secondary metabolites in stromata and cultures by high performance liquid chromatography, coupled with diode array and mass spectrometric detection (HPLC-DAD/MS), and on its phylogenetic affinities based on 5.8S/ITS rDNA sequence data, respectively, revealed a close relationship of the new taxon to the genera Daldinia and Entonaema, from which it differs by having neither a hollow, gelatinous nor a conspicuously zonate stromatal interior, and an anamorph featuring enteroblastic rather than holoblastic conidiogenesis. A specimen from the same geographic region, previously identified as Daldinia bakeri by R.W.G. Dennis was found to constitute a mixture of stromata of Ruwenzoria and an additional, undescribed Daldinia species. The latter fungus is not formally described due to the scantiness of the material, but its morphological characteristics are illustrated

Metatranscriptomics reveals unsuspected protistan diversity in leaf litter across temperate beech forests, with Amoebozoa the dominating lineage

Forest litter harbors complex networks of microorganisms whose major components are bacteria, fungi and protists. Protists, being highly selective consumers of bacteria and fungi could influence decomposition processes by shifting competitive microbial interactions. We investigated the eukaryotic diversity from 18 samples of one-year beech (Fagus sylvatica) leaf litter by RNA-based high-throughput sequencing of the small-subunit ribosomal RNA gene. By applying a metatranscriptomics approach, we avoided biases inherent to PCR-based methods, and could therefore focus on elusive protistan groups. We obtained 14 589 eukaryotic assembled sequences (contigs) representing 2223 unique taxa. Fungi dominated the eukaryotic assemblage, followed by an equal proportion of protists and plants. Among protists, the phylum Amoebozoa clearly dominated, representing more than twice the proportion of Alveolata (mostly ciliates) and Rhizaria (mostly Cercozoa), which are often retrieved as the dominant protistan groups in soils, revealing potential primer biases. By assigning functional traits to protists, we could assess that the proportion of free-living and heterotrophs was much higher than that of parasites and autotrophs, opening the way to a better understanding of the role played by the protistan communities and how biodiversity interacts with decomposition processes

Affinities of Phylacia and the daldinoid Xylariaceae, inferred from chemotypes of cultures and ribosomal DNA sequences

A chemotaxonomic evaluation using hplc profiling was undertaken to resolve the infrageneric and intergeneric affinities of over 150 strains of Xylariaceae. Daldinia placentiformis, Hypoxylon nicaraguense, H. polyporus, and Phylacia sagrana were found to contain 8-methoxy-1-naphthol, which is apparently absent in Annulohypoxylon, Hypoxylon, and related genera with bipartite stromata. D. placentiformis and other species of Daldinia and Entonaema produced this naphthol, 5-hydroxy-2-methylchromone, isosclerone derivatives, and 'AB-5046' phytotoxins. Phylacia sagrana differed from most Daldinia spp., except for D. caldariorum, by producing eutypine derivatives in addition to the above compounds. indolylquinones were observed in H. nicaraguense and H. polyporus. Isosclerones were also identified in the A. multiforme complex, but Hypoxylon and other Annulohypoxylon and most Hypoxylon spp. studied Annulohypoxylon spp. contained S-methylmellein as the major metabolite of their cultures. Based on the occurrence of the above metabolites, further mellein-type dihydroisocoumarins, teleomorphic and anamorphic Xylariaceae with Nodulisporium-like anamorphs ('Hypoxyloideae') were divided into various chemotypes. A comparison of their 5.8S/ ITS nuc-rDNA sequences agreed in some important aspects with the above results: H. nicaraguense and H. polyporus appeared basal to a clade comprising Daldinia, Entonaema, and Ph. sagrana. The latter species appeared allied to D. caldariorum, but was distantly related to Pyrenomyxa morganii and Hypoxylon s. str. (C) 2007 The British Mycological Society. Published by Elsevier Ltd. All rights reserved