AMF

Rhizophagus irregularis (formerly Glomus intraradices)

Also known as: Arbuscular Mycorrhizal Fungus

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Edibility inedible
Phylum Glomeromycota
Family Glomeraceae
Conservation Not applicable - ubiquitous and essential

Complete Taxonomy

Kingdom: Fungi
Phylum: Glomeromycota
Class: Glomeromycetes
Order: Glomerales
Family: Glomeraceae
Genus: Rhizophagus
Species: R. irregularis

Description

Rhizophagus irregularis is perhaps the most commercially important and widely studied arbuscular mycorrhizal fungus. Forming symbioses with over 80% of plant families, it dramatically improves plant nutrition, particularly phosphorus uptake, while receiving carbon from the plant. This species is mass-produced for use in agriculture, horticulture, and land restoration, reducing fertilizer needs and improving plant health.

Physical Characteristics

Cap Shape: Microscopic; extensive hyphal network and large spores
Cap Color: Hyphae hyaline; spores cream to yellowish
Size: Spores 80-200 micrometers diameter; hyphae network extends meters
Gill Attachment: N/A
Spore Print: N/A
Stipe: Coenocytic hyphae; forms characteristic arbuscules in root cells
Habitat: Plant roots and rhizosphere soil
Fruiting Season: Continuous spore production in association with living roots

Distribution

Cosmopolitan; worldwide in diverse ecosystems

Habitat

Forms arbuscular mycorrhizae with diverse plants including crops, vegetables, ornamentals, and wild species. Found in agricultural, grassland, forest, and desert soils.

Ecological Role

Critical mutualist improving plant nutrient acquisition (especially phosphorus), water uptake, and stress tolerance. Forms common mycelial networks linking plants. Essential for ecosystem productivity and plant diversity.

Cultural Significance

Model organism for mycorrhizal research. Commercially produced biofertilizer industry. Central to sustainable agriculture and organic farming movements. Reduces chemical fertilizer dependence.

Fascinating Facts

  • First AM fungus to have genome sequenced
  • Cannot survive without living plant host
  • Improves plant phosphorus uptake 100-fold
  • Reduces fertilizer needs by 30-70%
  • One fungal network connects multiple plant species
  • Improves plant drought and disease resistance
  • Contains hundreds of genetically distinct nuclei
  • Used commercially in millions of hectares worldwide
  • Ancient symbiosis dating 400+ million years