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Related to Ascomycota: Basidiomycota, Deuteromycota


a phylum of the kingdom FungiFungi
, kingdom of heterotrophic single-celled, multinucleated, or multicellular organisms, including yeasts, molds, and mushrooms. The organisms live as parasites, symbionts, or saprobes (see saprophyte).
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A phylum in the kingdom Fungi, representing the largest of the major groups of fungi, and distinguished by the presence of the ascus, a specialized saclike cell in which fusion of nuclei and reduction division occur and the resulting nuclei form ascospores. In most ascomycetes, each ascus contains eight ascospores, but the number may vary from one to several hundred. In the simplest ascomycetes (yeasts), the vegetative body (thallus) is unicellular; however, in the majority of ascomycetes, the thallus is more complex and consists of a tubular, threadlike hypha with cross walls which grows in or on the substrate. These hyphae eventually form structures called ascomata (ascocarps), on or in which the asci are formed. In addition to their sexual reproduction, most ascomycetes reproduce asexually by means of conidia.

Traditionally, the structure of the ascoma and ascus has served as the basis for subdividing the Ascomycota into five classes: Hemiascomycetes, Plectomycetes, Pyrenomycetes, Discomycetes, Loculoascomycetes. The introduction of molecular data, however, is changing concepts of the relationships of different groups of ascomycetes and will eventually lead to a much-revised classification scheme.

The ascomycetes occur throughout the world in all types of habitats and on both living and dead substrates. An estimated 33,000 species are arranged in about 3300 genera, with new species being described regularly. Ecologically ascomycetes function as primary decomposers of plant materials, but they also are important as plant and human pathogens; in baking, brewing, and winemaking; in enzyme and acid production; and as sources of antibiotics and other drugs. See Eumycota, Fungi, Plant pathology, Yeast

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Towards a revised generic classification of lecanoroid lichens (Lecanoraceae, Ascomycota) based on molecular, morphological and chemical evidence.
Tabela 1--Lista dos fungos ectomicorrizicos associados a nogueira-peca relatados na literatura Table 1--List of ectomycorrhizal fungi associated to pecan trees and reported in the literature Classificacao Distribuicao ASCOMYCOTA Cenococcum geophilum Georgia, E.U.A.
Cephalotheca was the genus of fungi in the Cephalothecaceae family of the Ascomycota. It was the core genus with high abundance of 12.63% (in S1) and 16.70% (in S2) in AOScontaminated soils.
latifolia, 24 fungal species mainly in the fungi divisions Basidiomycota and Ascomycota were selected for phylogenetic analysis.
First report of family Morchellaceae (Ascomycota: Pezizales) for Colombia
Most of the lichenized fungi belong to the phylum Ascomycota (98% of lichen species) and, among them, Parmeliaceae (Ascomycota, Lecanorales) represents the largest family of lichens.
Keywords: Ascomycota, Basidiomycota, checklist, Eumycola, fungi, taxonomy
Most macrofungus or mushroom species are under the Basidiomycota and Ascomycota, the two phyla under the Kingdom Fungi [2].