mycorrhiza

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Related to mycorrhizal: Mycorrhizal fungi

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 ?
These studies aim to develop biotechnological methods for the use of soil microorganisms in both sustainable soil management and acerola crop production associated with AMF because this plant is mycotrophic, that is, it requires mycorrhizal association to enhance nutrient absorption, particularly of phosphorus, thereby increasing the plant growth and productivity (BALOTA et al.
lt;B Paul Thomas with truffles that have been cultivated in the UK for the first time Mycorrhizal Systems Ltd/Simon
Mycorrhizal fungi perform a significant role as bio-protectant against pathogens (Naher et al.
Introduced AMF significantly improved mycorrhizal root colonization levels, growth and yield as compared to the indigenous AMF alone.
being minute and containing very little to no nutrient reserve for seed germination (Arditti & Ghani, 2000), orchid seed germination and seedling development are dependent on association of appropriate mycorrhizal fungi as a carbon source.
2009) or the reduced mycorrhizal dependence of the climax species, of low growth rate (Sturmer & Siqueira, 2011; Bonfim et al.
Although it has been observed that native plants of the Caatinga present a mycorrhizal responsiveness modulated by the adverse conditions of the environment, such as low nutrient availability, including phosphorus (Sousa, Maia, Menezes, Sampaio, & Garrido, 2008) there are, as yet, few works that list the benefits of this symbiosis on survival and development of native plants in semiarid regions (Maia, Silva, Yano-Melo, & Goto, 2010) and/or demonstrate the functional role of indigenous isolates from the biome in the development of native plants.
The obligate biotrophic nature of arbuscular mycorrhizal fungi (AMF) has been well documented wherein their association with plant roots provides benefits for both plant and fungi (Mehrotra, 2005).
Mycorrhizal fungi could one day act as a bio-fertilizer who will enhance fertility of the soil, ultimately yields will be high without using any external fertilizer.