Ainsworth classification of Fungi - Flow chart with Example and Salient Features

Lets us begin with a definition of fungus.
Fungi are microscopic or macroscopic, eukaryotic, haploid, non-chlorophyllated, spore-bearing, filamentous, heterotrophic thallophytes which  reproduce asexually and sexually.
Geoffrey Clough Ainsworth (1905-1998)
He published this classification as a paper in a journal in 1966. Then modified and published in  "Ainsworth and Bisby's Dictionary of the Fungi" (1971) and "The Fungi. An Advanced Treatise" (1973)

Kingdom Mycota (Fungi) is divided into 2 Divisions
Ainsworth classification of Fungi Flow chart with example

1. Myxomycota (Slime moulds)
  • Slime moulds
  • Characters of both animals and plants
  • Not cellular, holocarpic diploid
  • Amoeboid protoplasm without a cell wall
  • Plasmodium: single, large multinucleate protoplast (coenocytic)
  • Example: Physarum
2. Eumycota (True Fungus)
  • True Fungus which is Cellular, filamentous, haploid, Unicellular or multicellular with Chitinous Cell wall
  • Thallus made up of Hyphae and mycelium
  • Example: Agaricus, Penicillium,

Myxomycota further divided into 4 classes
1.  Acrasiomycetes (Cellular slime molds)
Free-living assimilatory phase forming psuedoplasmodium 
Example: Dictyostelium

2. HydroMyxomycetes (Net slime molds): network like appearance   
Example: Labyrinthula

3. Myxomycetes (True slime molds): free-living saprobic plasmodium 
Example: Physarum

4. Plasmodiophoromycetes (endoparasitic slime molds) that lives inside a host 
Example: Plasmodiophora

This is a summarized video on Ainsworth classification of Fungi:

Eumycota is divided into 5 Subdivisions
  • Aseptate coenocytic, Asexual reproduction by zoospores (flagellated motile spores)
  • Sexual reproduction: gametangial copulation
  • Example: Albugo, Pythium, Saprolegnia
2. Zygomycotina
  • Aseptate coenocytic, Asexual reproduction by non motile spores produced inside sporangium.
  • Flagellated cells absent
  • Sexual reproduction by gametangial fusion followed by resistant Zygospore formation
  • Example: Rhizopus
3.Ascomycotina (Sac fungus)
  • Called as Sac fungi as sexual ascospores are formed inside a sac-like structure called ascus.
  • Septate, well developed mycelium
  •  Asexual reproduction by nonmotile conidia, flagellated cells absent.
  • Sexual reproduction by ascospores (often 8 in number)
  • Ascocarp or fruiting body may be  apothecium (cup-shaped as in Peziza), Perithecium (flask-shaped as in Xylaria) or cleistothecium (closed as in Penicillium)
  • Example: Saccharomyces, Penicillium, Peziza
4.Basidiomycotina (Club fungus)
  • Most abundant and advanced group of fungus
  • Called club fungi as basidiospores are formed on club shaped structure called a basidium
  • Septate well-developed mycelium with dolipore septum; a a special type of septum.
  •  Asexual reproduction by non-motile exogenously produced conidia.
  • Sexual reproduction by basidiospores formed on basidia
  • Example: Agaricus, Puccinia
5. Deuteromycotina
  • Called Fungi imperfecti as sexual reproduction is absent
  • Septate well-developed mycelium
  • Asexual reproduction non-motile conidia sometimes organized to form sporodochia.
  • Sexual reproduction absent 
  • Example: Fusarium, Cercospora
Ainsworth’s paper: Ainsworth, G. C. (1966). A general-purpose classification of fungi. Bibl. Syst. Mycol1, 1-4.

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