Mycorrhizal Fungi

Mycorrhizal fungi 

If you have ever got to enjoy the shade of an oak, embellished a pine, spruce or Douglas fir as a Christmas tree, loved the beauty of an orchid, or eaten a blueberry or chanterelle mushroom, you have been benefited from the hidden world of mycorrhizal fungi, a world that makes the survival of most of earth's land plants possible.

Mycorrhizal fungal filaments (mycelia) radiate into the soil from mycorrhizae-colonized root tips, extending the capacity of the plant’s root system to absorb water and nutrients

Mycorrhizal fungi have existed since the first plants appeared on dry land more than 450 million years ago. They form a close symbiotic relationship with plant roots. They are referred as mycorrhizae from the Greek "mukés", that means fungus, and "rhiza," that means roots.

The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis. Mycorrhizae also offer the host plant increased protection against certain pathogens.

Mycorrhizae forms a network of fine filaments that associate itself with the plant roots and it draw nutrients and water from the soil that the root system would not be able to access otherwise. This fungus-plant alliance stimulates plant growth and accelerates root development.

Mycorrhizae are formed with more than 90% of plant species. Mycorrhizal fungi encompass many major groups of the fungus Kingdom and in the past they were divided into two non-evolutionarily related groups: the ectotrophic and endotrophic based upon the position of the fungal hypae in relation to the tissues of a plants roots. Ectomycorrhizal fungi ensheath the root cells but usually do not penetrate them (extracellular). Endomycorrhizal fungi penetrate and enter the cells of a plant root (intracellular). 

Modern research has lead to the recognition of seven varieties of mycorrhizal fungi, subdividing the old, traditional groups. The new nomenclature is often more precise and specific to the associated plant taxa. The relatively homogenous ectomycorrhizal group largely remains with only the addition of the subgroup ectendomycorrhizas. The endomycorrhizal group has been destroyed, but specific types are now recognized: Vescicular-Arbuscular Mycorrhizas, the Orchid mycorrihzas, and those which associate with the Ericaceae (Blueberry family): the Arbutoid, Monotropoid and Ericoid mycorrhizas. 

Benefits of Mycorrhizae

Mycorrhizal fungi enable plants to draw more nutrients and water from the soil. They additionally increase plant tolerance to different environmental stresses. Moreover, these fungi play a significant role in soil aggregation process and stimulate microorganism activity. According to the plant species and to the growing practices and conditions, mycorrhizae provide different advantages to the plants and to the environment:

·        Produce more vigorous and healthy plants

·        Increase plant establishment and survival at seeding or transplanting

·        Increase yields and crop quality

·        Improve drought tolerance, allowing watering reduction

·        Enhance flowering and fruiting

·        Optimize fertilizers use, especially phosphorus

·        Increase tolerance to soil salinity

·        Reduce disease occurrence

·        Contribute to maintain soil quality and nutrient cycling

·        Contribute to control soil erosion

-Ruhi