BASIDOMYCOTINA| Sub- Division IV

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Subkingdom: Mycota
Division: Eumycota
Sub-division: Basidomycotina

  • G.C. Ainsworth’s system of classification includes Basidomycotina which is a subdivision under Eumycota
  • This is also known as Club Fungi
  • This is also non-motile fungi.
  • These group of fungi are known to be true fungi.
  • Major edible fungi belong to this Phylum
  • It is a large group of fungi having around 30000 species.
  • They include mushrooms and toadstools, bracket fungi, puffballs, earth stars, stinkhorns, false truffles, jelly fungi, earth balls and some less familiar forms.

 

BASIDOMYCOTINA| Sub- Division IV
Club Fungi

General Characteristics

  • These have septate and multinucleate mycelium while some are yeast-like and others are dimorphic
  • They are known as club fungi due to the presence of club-shaped basidium.
  • Fruiting bodies are called basidiocarps
  • These are found in the tip of the stalks called sterigmata
  • Cell wall made up of chitin
  • They have well developed filamentous mycelium
  • Adjacent cells are separated by dolipore septa
  • The transverse septa which divide both monokaryotic and dikaryotic hyphae into segments
    contain a central pore which allows cytoplasmic continuity between adjacent segments. The septal pore is surrounded by a barrel-shaped flange of thickened wall material called dolipore
    septa which are a characteristic feature of Basidiomycotina
  • They are found in terrestrial regions but some grow in freshwater or marine habitats.
  • They may be saprotrophic and are involved in litter and wood decay.
  • The fruit bodies of many mushrooms are edible Ex. Agaricus bisporus, Pleurotus spp, Lentinula edodes.
  • They possess both sexual and asexual reproduction
  • Basidiomycota are known to be related to Ascomycota

Classification

  1. Teliomycetes
  2. Hymenomycetes
  3. Gastromycetes

Reproduction

It undergoes vegetative, asexual and sexual reproduction.

Vegetative Reproduction

  1. Fragmentation
  2. Budding

Asexual Reproduction

  1. Conidia formation– It may develop on monokaryotic or dikaryotic mycelia. In rusts, smuts, etc
  2. Oidia- It may develop on monokaryotic and dikaryotic mycelia
  3. Clamydospores- They are formed terminally on aerial branched conidiophores which develop from a mycelium lacking clamp connections.

Sexual Reproduction

  • It also involves plasmogamy, karyogamy and meiosis.
  • Plasmodium forms the dikaryotic mycelium
  • Karyogamy and meiosis leads to the formation of basidiospores

Basidiospores

  • These are small, haploid, thin-walled and uninucleate cells produced exogenously on the basidium.
  • The number of basidiospores produced by a single basidiocarp can be extremely high.
  • They are transported by the wind current, insect or rain etc. and later start germinating.
  • These are considered sexual spores as they combine the genetic material from both the strains.

Life Cycle

  • It includes alternation of generations
  • It takes place in the fruiting body in basidia
  • The basidia are formed by plasmogamy
  • Many of these fungi in this group have a dimorphic life cycle.
  • The life cycle continues in 3 phases-
BASIDOMYCOTINA| Sub- Division IV
Lifecycle of a basidomycotina
  1. Plasmogamy- The haploid donor cell nucleus penetrates cytoplasm of the recipient cell
  2. Karyogamy- Two strains of nuclei fuse together
  3. Meiosis- The diploid nucleus produces haploid nuclei

Economic Importance

  • Most edible fungi fall in this group
  • Many of these fungi are also pathogenic in nature
  • Sporobolomyces roseus basidiospores is a cause for respiratory allergens which is found on moribund leaf surfaces.
  • Another is Cryptococcus neoformans, which grows commonly on old “weathered” bird droppings, and which can cause a fatal systemic infection of immunocompromised people. Its air-borne basidiospores initiate infection via the lungs, leading to the disease termed cryptococcosis.

Reference

  1. Introduction to Fungi, Third Edition
  2. https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/basidiomycetes
  3. https://courses.lumenlearning.com/suny-biology2xmaster/chapter/classification-of-fungi/
  4. http://archive.bio.ed.ac.uk/jdeacon/microbes/basidio.htm

More Topics To Read

  1. CLASSIFICATION OF FUNGI
  2. MASTIGOMYCOTINA| Sub- Division I
  3. ZYGOMYCOTINA| Sub- Division II
  4. ASCOMYCOTINA| Sub- Division III
  5. DEUTEROMYCOTINA| Sub- Division V