Further advances in orchid mycorrhizal research

• Published in: Mycorrhiza Vol. 17; no. 6; pp. 475 - 486
• Main Author: Dearnaley, John D. W
• Format: Journal Article
• Language: English
• Published: Berlin Berlin/Heidelberg : Springer-Verlag 01.09.2007; Springer; Springer Nature B.V
• Subjects: Ascomycota - classification; Ascomycota - physiology; Basidiomycota - classification; Basidiomycota - physiology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Fungi; Gene expression; Mixotrophy; Myco-heterotrophy; Mycorrhizae - physiology; Orchid mycorrhizas; Orchidaceae; Orchidaceae - classification; Orchidaceae - microbiology; Orchidaceae - physiology; Parasitism and symbiosis; Plant physiology and development; Plant Roots - microbiology; Rhizoctonia; Russulaceae; Symbiosis; Monocotyledones; Rhizoctonia; Seeds; Gene expression; Fungi; Orchid mycorrhizas Mixotrophy. Myco-heterotrophy; Orchidaceae; Angiospermae; Mycorrhiza; Spermatophyta; Fungi Imperfecti; Photosynthesis; Thallophyta; Rhizoctonia·Russulaceae
• ISSN: 0940-6360; 1432-1890
• DOI: 10.1007/s00572-007-0138-1

Orchid mycorrhizas are mutualistic interactions between fungi and members of the Orchidaceae, the world's largest plant family. The majority of the world's orchids are photosynthetic, a small number of species are myco-heterotrophic throughout their lifetime, and recent research indicates a third mode (mixotrophy) whereby green orchids supplement their photosynthetically fixed carbon with carbon derived from their mycorrhizal fungus. Molecular identification studies of orchid-associated fungi indicate a wide range of fungi might be orchid mycobionts, show common fungal taxa across the globe and support the view that some orchids have specific fungal interactions. Confirmation of mycorrhizal status requires isolation of the fungi and restoration of functional mycorrhizas. New methods may now be used to store orchid-associated fungi and store and germinate seed, leading to more efficient culture of orchid species. However, many orchid mycorrhizas must be synthesised before conservation of these associations can be attempted in the field. Further gene expression studies of orchid mycorrhizas are needed to better understand the establishment and maintenance of the interaction. These data will add to efforts to conserve this diverse and valuable association.