mycorrhiza

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Related to Ectomycorrhizal fungus: mycorrhizae

mycorrhiza

or

mycorhiza

(mī′kə-rī′zə)
n. pl. mycorrhi·zae (-zē) or mycorrhi·zas
The symbiotic association of the mycelium of a fungus with the roots of a plant, as is found in the majority of vascular plants.

my′cor·rhi′zal adj.

mycorrhiza

(Greek myco- fungus, rhiza root) an association between a FUNGUS and the roots of a higher plant. In some cases the fungus breaks down PROTEINS or AMINO ACIDS that are soluble and can be absorbed by the higher plant. In most cases, only nitrogen and phosphorus compounds result from fungal activity. Carbohydrates synthesized by the higher plants are absorbed by the fungus, so the relationship is a form of SYMBIOSIS. Some plants which lack chlorophyll, such as the bird's nest orchid, rely on mycorrhizas for carbohydrates in addition to protein.

There are two types of mycorrhiza: ectomycorrhiza and endomycorrhiza. In an ectomycorrhiza the infecting fungus occurs on the surface of the root and possibly between the cells of the root cortex, but does not penetrate such cells. The root becomes covered by a sheath of fungal tissue and looks different from an uninfected root. It is thicker, has no root hairs or root cap and may be a different colour. Ectomycorrhizae are found mainly on trees, such as oak and pine. In an endomycorrhiza the fungus develops within the cells of the root cortex. Subsequently the root cells digest the fungus leaving only knots of fungal material in the cells. There is usually little difference in the morphology of the root and a sheath of fungal tissue is not normally formed.

References in periodicals archive ?
2]-fixing Casuarina cunninghamiana linked by the ectomycorrhizal fungus Pisolithus sp.
2004) and the ectomycorrhizal fungus Laccaria bicolor (Bertaux et al.
in the mycelium of the ectomycorrhizal fungus Laccaria bicolor S238N.
Rapid reactions of spruce cells to elicitors released from the ectomycorrhizal fungus Hebeloma crustuliniforme, and inactivation of these elicitors by extracellular spruce cell enzymes.
This species is considered an ectomycorrhizal fungus in Japan although the species of genus Lyophylum Karsten have been considered saprophytic fungi in Europe.
The monokaryotic strain the ectomycorrhizal fungus Hebeloma cylindrosporum (h1) was obtained from single spore germination [13].
In vitro fruiting under controlled conditions of the ectomycorrhizal fungus Hebeloma cylindrosporum associated with Pinus pinaster.
Effect of the ectomycorrhizal fungus Hebeloma hiemale on adventitious root formation in demoted Pinus halepensis hypocotyls.
For example, based upon RFLP analysis, we observed that 42% of the root tips at one site, Sunset Crater, were colonized by a single type of ectomycorrhizal fungus.
and the ectomycorrhizal fungus Hebeloma cylindrosporum: effect of ectomycorrhizal symbiosis.
Species-specific primers for the identification of the ectomycorrhizal fungus Tuber macrosporum Vittad.
Mycorrhizal morphotyping and molecular characterization of Chondrogaster angustisporus Giachini, Castellano, Trappe, Oliveira, an ectomycorrhizal fungus from Eucalyptus.