Glossary

AMF:

This is an abbreviation for "Arbuscular Mycorrhizal Fungi"

 

Arbuscles:
These are intricately branched "treelike" structures within the cortex of a mycorrhizal colonized plant root. They are the transfer point where hyphae deliver elemental nutrients from the soil to the plant and where the plant releases carbohydrates to the fungi in exchange.

 

CMN:
Common Mycorrhizal Network, a term that refers to what earlier soil scientists called a "Super Organism". It is the complex network that ties an entire ecosystem together and can actually transport nutrients and moisture from one location to another, redistributing supplies to maintain an overall healthy ecosystem.

 

Ecto-Mycorrhizal Fungi:
A form of mycorrhizae that associates with most conifers as well as some hardwoods such as oaks. The fruiting bodies of this organism can be counted among the wild mushrooms and toadstools found in forests. As the reproductive spores of this fungi become airborne upon release from the sporocarp, their ability to freely colonize emerging seedlings is highly effective. The use of commercially available ecto inoculant is only necessary under certain conditions such as the introduction of a host plant into an area that does not have any other ecto hosts in close proximity. Another application may be in a tissue culture nursery where colonization must be conducted under aseptic conditions.

 

Endo-Mycorrhizal Fungi:
Also known as VAM, (vesicular arbuscular mycorrhizae) and AMF (arbuscular mycorrhizal fungi. This organism forms associated with the greater majority of terrestrial plants, (between 80% and 90) . Colonization occurs in the soil by plant roots connecting with hyphae, spores of colonized roots. It may also be transported by insects and small animals in the soil. The spores are not as abundant as ecto-mycorrhizal spores and are much heavier. Therefore, air transport is much rarer and not an efficient means of colonizing disturbed areas.

 

Ericoid Mycorrhizae:
More commonly associated with wetland or bog plants such as blueberries, cranberries, gaultheria, heathers, rhododendrons and azaleas. Ericoid mycorrhizae only grow in the out surface of the host plants roots and do not mine areas of the soil in manners similar to ecto or endo mycorrhizae.

 

Hyphae:
Microscopic filaments that connect the roots of plants to the water and nutrients. A hypha (plural hyphae) is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.

 

Mycorrhizal Dependency:
This is a measure of the level of benefits that are provided to a plant by the fungi.


Obligatory Plants

are those species that will not survive to reproductive maturity without a mycorrhizal association.


Facultative Mycorrhizal Plants

benefit from an Association under certain , generally low Nutrient conditions.


Nonmycorrhizal Plants:

are plants that resist colonization and function effectively without the association. Unfortunately, these generally fall into the categories of "weeds", "ruderalls" and "Invasive Species".

 

Mycorrhizae, Mycorrhizal or Mycorrhiza:
Which one is it? It is actually more important than you might think if one is to grasp a fundamental component of soil biology. It goes like this: Mycorrhizae: A Greek (Mykos) / Latin (Rhizae) Term that means a fungus of the roots.
 

Mycorrhiza or Mycorrhizosphere:

is the entire area in the soil that is dominated by the mycorrhizal fungi and the roots of host plants.


Mycorrhizal

is an adjective and as can be visualized by this chart, the influence of mycorrhizae can be connected to the host plant and the soil when the fungi and plant enter into a symbiotic relationship.

 

Spores:
These are the "fruiting bodies" of the fungi and are formed both inside the roots and externally in the soil. Depending upon the season and conditions, spores can make up a significant amount of mycorrhizal biomass.

Pure mycorrhizal inoculum cultured by RTI. This test sample contains several thousand propagules per gram. Photo courtesy of Fernando Morell (Mycorrhizal Production, Research and Development Manager; Reforestation Technologies International)

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