Dothideomycetes

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Dothideomycetes
Cellar cloth (Zasmidium cellare) hanging from a vaulted ceiling

Cellar cloth ( Zasmidium cellare ) hanging from a vaulted ceiling
Systematics
without rank: Nucletmycea
Empire : Mushrooms (fungi)
Sub-kingdom : Dikarya
Department : Ascomycota mushrooms
Subdivision : Real ascent mushrooms (Pezizomycotina)
Class : Dothideomycetes
Scientific name
Dothideomycetes
OE Erikss. & Winka

The Dothideomycetes are a class of the hose fungi .

features

The fruiting bodies are bottle-shaped, disc-shaped or spherical. The peculiarity of the class lies in the development of the fruiting bodies: The asci develop in free spaces (loculi) that are formed by the dissolution of tissue (lysigenic) within the vegetative hyphae . This type of fruiting body formation, known as "ascolocular", is in contrast to the ascohymenial formation that is widespread in most of the rest of the real sac fungi.

The ascus wall is bitunicate, which means that it consists of two layers that can be stretched to different degrees. The thin outer layer (Exotunica) is inelastic and tears at a certain turgor pressure . The inner layer (endotunica) is thicker and stretches lengthways as the turgor increases. The individual ascospores clog the porus at the apex of the ascus and are expelled one after the other. The turgor increases through the conversion of osmotically inactive substances into osmotically active substances, probably through the breakdown of glycogen into simple sugars. This form of spore expulsion is called fissitunicat.

The formation of the tissue and cells in the cavity of the sexual structure, the so-called center, is important for the structure of the order. The sterile Centrum tissue, the hemathecium, is particularly important .

Some families ( Pleosporaceae , Mycosphaerellaceae , Tubeufiaceae ) are rich in anamorphic species. These include hyphomycete and coelomycete species. Among the hyphomycetes there are many whose conidia- forming cells branch sympodially . The Coelomycetes have phialidic, annellidic or holoblastic conidia-forming cells, and form small, aseptate conidia in a mucus. This group also includes many “black yeasts” that form dark mucus colonies, the spore formation of which resembles the budding of real yeasts .

Way of life

The species of Dothideomycetes live as pathogens, endophytes or epiphytes in or on plants, or as saprobionts that break down cellulose and other carbohydrates in dead or half-digested plant material. Some species are lichens , some others are parasites on fungi or animals .

Systematics

The question of whether the Dothideomycetes are a natural family group, i.e. a monophyletic taxon , has not yet been finally clarified. On the basis of DNA sequence analyzes, some orders that were previously included in the Dothideomycetes due to their bitunicate ascus structure have already been placed in other classes, such as the Verrucariales and the Chaetothyriales . Monophyly of the class at its current level is likely. The sister group of the Dothideomycetes are the Arthoniomycetes .

Eight orders are counted among the Dothideomycetes, of which only a part can be assigned to one of the two subclasses.

meaning

The Dothideomycetes include some pathogens causing plant diseases: Venturia causes scabs on apples and pears. Capnodium causes black-brown soot on leaves, but only feeds on leaf and aphid excretions in a saprobionic way. Herpotrichia attacks snow-covered coniferous branches in the alpine altitudes and causes them to die.

Individual evidence

  1. ↑ a b c d e f Schoch et al .: A multigene phylogeny of the Dothideomycetes using four nuclear loci , 2006.
  2. ^ A b Peter Sitte , Elmar Weiler , Joachim W. Kadereit , Andreas Bresinsky , Christian Körner : Textbook of botany for universities . Founded by Eduard Strasburger . 35th edition. Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-1010-X , p. 626 .
  3. ↑ DS Hibbett et al .: A higher-level phylogenetic classification of the Fungi . In: Mycological research , May 2007; 111 (5): 509-547. Epub 2007 March 13, 2007. doi : 10.1016 / j.mycres.2007.03.004 , (PDF; 1.3 MB)

literature

  • Conrad L. Schoch, Robert A. Shoemaker, Keith A. Seifert, Sarah Hambleton, Joseph W. Spatafora & Pedro W. Crous: A multigene phylogeny of the Dothideomycetes using four nuclear loci . In: Mycologia , Volume 98, 2006, pp. 1041-1052. (on-line)

Web links

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