Orchid mycorrhiza

Orchid mycorrhizae are symbiotic relationships between the roots of plants of the family Orchidaceae and a variety of fungi. All orchids are myco-heterotrophic at some point in their life cycle. Orchid mycorrhizae are critically important during orchid germination, as an orchid seed has virtually no energy reserve and obtains its carbon from the fungal symbiont. Many adult orchids retain their fungal symbionts, although the benefits to the adult photosynthetic orchid and the fungus remain largely unexplored.

Fungi forming orchid mycorrhizae

The fungi that form orchid mycorrhizae are typically basidiomycetes. These fungi come from a range of taxa including Ceratobasidium (Rhizoctonia), Sebacina, Tulasnella and Russula species. Most orchids associate with saprotrophic or pathogenic fungi, while a few associate with ectomycorrhizal fungal species. These latter associations are often called tripartite associations as they involve the orchid, the ectomycorrhizal fungus and the ectomycorrhizal host plant.

See also

• Mycorrhiza

External links

• "Orchid Mycorrhiza", from Fungal Biology (online textbook), School of Biological Sciences, University of Sydney, June 2004:
  • "Function of Orchid Mycorrhizas"
  • "Symbionts of Orchid Mycorrhiza"
• "Orchidoid mycorrhizae" from Mycorrhizae and Plant Phylogeny (website) by Frank C. Landis, Botany Department, University of Wisconsin–Madison, January 11, 2002.