Ericoid mycorrhiza
Encyclopedia
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
s of plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s from the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Ericales
Ericales
The Ericales are a large and diverse order of dicotyledons, including for example tea, persimmon, blueberry, Brazil nut, and azalea. The order includes trees and bushes, lianas and herbaceous plants. Together with ordinary autophytic plants, the Ericales include chlorophyll-deficient...
. Ericoid mycorrhiza
Mycorrhiza
A mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant....
are considered crucial for the success of the family Ericaceae
Ericaceae
The Ericaceae, commonly known as the heath or heather family, is a group of mostly calcifuge flowering plants. The family is large, with roughly 4000 species spread across 126 genera, making it the 14th most speciose family of flowering plants...
in variety of edaphically
Edaphic
Edaphic is a nature related to soil. Edaphic qualities may characterize the soil itself, including drainage, texture, or chemical properties such as pH. Edaphic may also characterize organisms, such as plant communities, where it specifies their relationships with soil...
stressful environments
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....
worldwide (Read, 1992). Ericaceous plants commonly co-occur in soils with leguminous or carnivorous plants (Read, 1996), further highlighting the low nutrient
Nutrient
A nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. They are used to build and repair tissues, regulate body processes and are converted to and used as energy...
status of these soils. Ericoid mycorrhizal fungi, which are predominately ascomycetes, enable their host plant to obtain nutrients in these depauperate soils.
Many of the fungi which form ericoid mycorrhizas are from the ascomycete order Helotiales
Helotiales
Helotiales is an order of the class Leotiomycetes within the division Ascomycota. According to a 2008 estimate, the order contains 10 families, 501 genera, and 3881 species.Helotiales is the largest order of inoperculate discomycetes...
. The best studied of these fungi is Rhizoscyphus ericae (=Hymenoscyphus ericae). R. ericae commonly occurs in symbiosis with a variety of ericaceous species from the northern hemisphere, but is not routinely found associated with Ericaceae (ex Epacridaceae) in the southern hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
(Cairney and Ashford, 2002).