Ecology and biogeography of myxomycetes

Plasmodial slime moulds (Myxomycetes) are a group of protista-like micro-organisms forming small but macroscopic fructifications. The thesis summarizes the results from a series of original papers on the ecology and diversity of Myxomycetes from the Arctic to the Neotropical zone. New microhabitats for these organisms are characterized ecologically, and a general picture about the distribution of myxomycete diversity among the major vegetations zones of the world is presented. Die plasmodialen Schleimpilze (Myxomycetes) sind protistenähnliche Mirkoorganismen, die kleine, aber makroskopische Ausmaße erreichende Fruktifikationen bilden. Die vorliegende Arbeit fasst die Ergebnisse einer Reihe von Originalarbeiten zur Ökologie und Artendiversität von Myxomyceten von der Arktis bis hin zur Neotropis zusammen. Neu entdeckte Mikrohabitate dieser Organismen werden vorgestellt, und ein Bild über die Diversitätsverteilung der Myxomyceten innerhalb der großen Vegetationszonen der Welt wird entworfen

A review of the Costa Rican myxomycetes (Amebozoa)

There has not been a comprehensive review of the taxonomic composition of the assemblage of myxomycetes known from Costa Rica since 1975. As a result of a series of studies carried out in the country during the last decade, considerable additional data now exist, and the review presented herein provides an update on this group of organisms. Collecting carried out in Costa Rica since 1975, a review of the published literature, and an examination of herbarium specimens were used to generate an annotated list consisting of a total of 208 species in 36 different genera. This includes 62 species not previously reported from Costa Rica. The relative abundance of the different orders follows the expected distribution for the Neotropics, with the order Physarales being the most abundant. Interestingly, the data also show that the distribution of species is highly heterogenous. This result suggests that most myxomycetes in Costa Rica are highly specialized for certain microhabitats defined by macro- and microenvironmental factors.Desde 1975 no se ha llevado a cabo una revisión exhaustiva de la composición taxonómica de los mixomicetes de Costa Rica. Como resultado de una serie de proyectos de investigación que se han desarrollado durante la última década, nueva información se encuentra disponible y es por ello que la presente revisión se considera como una actualización sobre este grupo de organismos para este país. El material recolectado desde 1975, una profunda revisión bibliográfica y el examen de especímenes de herbario fueron usados para generar una lista de 208 especies pertenecientes a 36 géneros diferentes. Esta lista incluye 62 especies no comunicadas anteriormente para Costa Rica. La abundancia relativa de los diferentes órdenes concuerda con la distribución esperada para el Neotrópico, siendo el orden Physarales el más abundante. De forma interesante, los datos también muestran que la distribución de las especies es altamente heterogénea. Este resultado sugiere que la mayoría de los mixomicetes en Costa Rica están altamente especializados alrededor de microhabitats definidos por factores macro y microambientales.Ministerio del Ambiente y Energía/[]/MINAE/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

Floristic inventories and distribution maps of vascular plants in Germany from the period between 1945 and 2005

In den letzten sechs Jahrzehnten wurden in Deutschland rund 200 nationale, regionale und lokale Florenwerke publiziert. Die vorliegende Arbeit gibt einen Überblick über die in diesen Publikationen enthaltenen Daten und stellt eine Karte mit den Bearbeitungsgebieten regionaler Florenwerke vor. Ein bibliografischer Teil zeigt die wichtigsten Daten für jede Publikation. Oft durch qualifizierte Amateurbotaniker erarbeitet, bilden solche Florenwerke eine wichtige Datenbasis insbesondere für Programme zum Artenschutz sowie für die Erstellung von Roten Listen.Within the last six decades about 200 national, regional, and local floristic inventories, often including distribution maps, for vascular plants in Germany have been published. An overview about the data provided by these publications is given together with a map displaying the coverage of regional and local inventories. A bibliography lists the key data for each publication. Often compiled by skilled volunteer botanists, such floristic inventories constitute an essential database for the compilation of Red Data Books and for species conservation

An Approach to the Virtual Flora of Mongolia – From a Data Repository to an Expert System, http://greif.uni-greifswald.de/floragreif/

FloraGREIF is an internet accessible information system providing taxonomic, phytogeographic and ecological information on Mongolia’s flora in terms of descriptions, high-resolution plant images and an interactive WebGIS application. Organised along an updated checklist of the approx. 3000 Mongolian vascular plants that serves as a taxonomic backbone, information is split into the taxon level, referring to plant species, and the record level, referring to record or a collected plant specimen. At the latter level, images of living plants, scans of herbarium sheets, habitat photos and further notes can be found. Both data levels are linked by the name of the respective plant species. An integrated WebGIS application enables the spatial visualisation at the taxon (distribution within phytogeographic units) and record level (dot maps). FloraGREIF is intended to be an internet accessible application tool for ecological and taxonomic research on Mongolia’s vegetation, but can serve as well as a data repository, e.g. for data from relevés survey

An Approach to the Virtual Flora of Mongolia – From a Data Repository to an Expert System, http://greif.uni-greifswald.de/floragreif/

FloraGREIF is an internet accessible information system providing taxonomic, phytogeographic and ecological information on Mongolia’s flora in terms of descriptions, high-resolution plant images and an interactive WebGIS application. Organised along an updated checklist of the approx. 3000 Mongolian vascular plants that serves as a taxonomic backbone, information is split into the taxon level, referring to plant species, and the record level, referring to record or a collected plant specimen. At the latter level, images of living plants, scans of herbarium sheets, habitat photos and further notes can be found. Both data levels are linked by the name of the respective plant species. An integrated WebGIS application enables the spatial visualisation at the taxon (distribution within phytogeographic units) and record level (dot maps). FloraGREIF is intended to be an internet accessible application tool for ecological and taxonomic research on Mongolia’s vegetation, but can serve as well as a data repository, e.g. for data from relevés survey

Treatment of Marburg and Ebola hemorrhagic fevers: A strategy for testing new drugs and vaccines under outbreak conditions.

The filoviruses, Marburg and Ebola, have the dubious distinction of being associated with some of the highest case-fatality rates of any known infectious disease-approaching 90% in many outbreaks. In recent years, laboratory research on the filoviruses has produced treatments and vaccines that are effective in laboratory animals and that could potentially drastically reduce case-fatality rates and curtail outbreaks in humans. However, there are significant challenges in clinical testing of these products and eventual delivery to populations in need. Most cases of filovirus infection are recognized only in the setting of large outbreaks, often in the most remote and resource-poor areas of sub-Saharan Africa, with little infrastructure and few personnel experienced in clinical research. Significant political, legal, and socio-cultural barriers also exist. Here, we review the present research priorities and environment for field study of the filovirus hemorrhagic fevers and outline a strategy for future prospective clinical research on treatment and vaccine prevention

Genetic structure of the protist Physarum albescens (Amoebozoa) revealed by multiple markers and genotyping by sequencing

Myxomycetes are terrestrial protists with many presumably cosmopolitan species dispersing via airborne spores. A truly cosmopolitan species would suffer from outbreeding depression hampering local adaptation, while locally adapted species with limited distribution would be at a higher risk of extinction in changing environments. Here, we investigate intraspecific genetic diversity and phylogeography of Physarum albescens over the entire Northern Hemisphere. We sequenced 324 field collections of fruit bodies for 1-3 genetic markers (SSU, EF1A, COI) and analysed 98 specimens with genotyping by sequencing. The structure of the three-gene phylogeny, SNP-based phylogeny, phylogenetic networks, and the observed recombination pattern of three independently inherited gene markers can be best explained by the presence of at least 18 reproductively isolated groups, which can be seen as cryptic species. In all intensively sampled regions and in many localities, members of several phylogroups coexisted. Some phylogroups were found to be abundant in only one region and completely absent in other well-studied regions, and thus may represent regional endemics. Our results demonstrate that the widely distributed myxomycete species Ph. albescens represents a complex of at least 18 cryptic species, and some of these seem to have a limited geographical distribution. In addition, the presence of groups of presumably clonal specimens suggests that sexual and asexual reproduction coexist in natural populations of myxomycetes

18S rDNA Phylogeny of Lamproderma and Allied Genera (Stemonitales, Myxomycetes, Amoebozoa)

The phylogenetic position of the slime-mould genus Lamproderma (Myxomycetes, Amoebozoa) challenges traditional taxonomy: although it displays the typical characters of the order Stemonitales, it appears to be sister to Physarales. This study provides a small subunit (18S or SSU) ribosomal RNA gene-based phylogeny of Lamproderma and its allies, with new sequences from 49 specimens in 12 genera. We found that the order Stemonitales and Lamproderma were both ancestral to Physarales and that Lamproderma constitutes several clades intermingled with species of Diacheopsis, Colloderma and Elaeomyxa. We suggest that these genera may have evolved from Lamproderma by multiple losses of fruiting body stalks and that many taxonomic revisions are needed. We found such high genetic diversity within three Lamproderma species that they probably consist of clusters of sibling species. We discuss the contrasts between genetic and morphological divergence and implications for the morphospecies concept, highlighting the phylogenetically most reliable morphological characters and pointing to others that have been overestimated. In addition, we showed that the first part (∼600 bases) of the SSU rDNA gene is a valuable tool for phylogeny in Myxomycetes, since it displayed sufficient variability to distinguish closely related taxa and never failed to cluster together specimens considered of the same species

Genetic Structure of Two Protist Species (Myxogastria, Amoebozoa) Suggests Asexual Reproduction in Sexual Amoebae

Plasmodial slime molds (Myxogastria or Myxomycetes) are common and widespread unicellular organisms that are commonly assumed to have a sexual life cycle culminating with the formation of often macroscopic fruiting bodies that efficiently disseminate spores. However, laboratory studies based on mating compatibility revealed the coexistence of asexual as well as sexual strains. To test this hypothesis in natural populations, we investigated the genetic variability of two species of the genus Lamproderma. Detailed ecological relevés were carried out in 2007 and 2009 in several deep ravines in the Elbsandsteingebirge (Saxony, south-eastern Germany). Morphological characters of 93 specimens of Lamproderma were recorded and genetic analyses, based on the small subunit ribosomal gene, the internal transcribed spacer 1 and partial elongation factor 1α sequences were carried out for 52 specimens. Genetic analyses showed the existence of two major clades, each composed of several discrete lineages. Most of these lineages were composed of several identical sequences (SSU, ITS 1 and EF-1α) which is explained best by an asexual mode of reproduction. Detrended Correspondence Analysis of morphological characters revealed two morphospecies that corresponded to the two major clades, except for one genotype (Lc6), thus challenging the morphospecies concept. Genetic patterns were not related to the geographical distribution: specimens belonging to the same genotype were found in distinct ravines, suggesting effective long-distance dispersal via spores, except for the Lc6 genotype which was found only in one ravine. Implications for the morphological and biological species concept are discussed