WHAT ARE MYCORRHIZAE?

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 called mycorrhizae from the Greek "mukés", meaning fungus, and "rhiza," meaning roots.

Mycorrhizae form a network of filaments that associate with plant roots and draw nutrients 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.

One kilometer of hypae (fine filaments) may be associated with a plant growing in a one-liter pot and it can access water and nutrients in the smallest pores in the soil. It also makes the plant less

 

susceptible to soil-borne pathogens and to other environmental stresses such as drought and salinity.In return the plant provides carbohydrates and other nutrients to the fungi. They utilize these carbohydrates for their growth and to synthesize and excrete molecules like glomalin (glycoprotein). The release of glomalin in the soil environment results in better soil structure and higher organic matter content.

However, in soil that has been disturbed by human activity, the quantity of mycorrhizae decreases drastically so that there are not enough of them to produce a significant benefit on plant growth and health, hence the importance to compensate for this lack.
       
  
     

Mycorrhizal fungi

    
     
  • Mycorrhizal fungi colonize the plant’s root system and develop a symbiotic association called “mycorrhiza”


  • They form a network of fine filaments that associate with plant roots and draw nutrients and water from the soil that the root system would not be able to access otherwise.


  • Mycorrhizae are formed with more than 90% of plant species
  
     
     

Benefits of Mycorrhizae

    
 
     

Mycorrhizal fungi allow plants to draw more nutrients and water from the soil. They also increase plant tolerance to different environmental stresses. Moreover, these fungi play a major role in soil aggregation process and stimulate microbial activity. According to the plant species and to the growing practices and conditions, mycorrhizae provide different benefits 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
Examples of these benefits are presented in the RESULTS section.
  Back to top
 

Types of mycorrhizae
 

There are two major groups of mycorrhizal fungi: ectomycorrhizal and endomycorrhizal fungi.
Members of the former group develop exclusively on the exterior of root cells, whereas those of the latter penetrate the plant cells where direct metabolic exchanges can occur. Ectomycorrhizae are essentially found on trees and form visible structures whereas endomycorrhizal fungi colonize trees as well as shrubs and most herbaceous plants and do not form visible structures.

 
   
       

Endomycorrhizae
Among the types of endomycorrhizal fungi, arbuscular mycorrhizal (AM) fungi are the most prevalent in soils. Their name is derived from structures they form within the plant root cell: arbuscules*.

*Arbuscules are finely-branched structures that form within a cell and serve as a major metabolic exchange site between the plant and the fungus. Vesicles are also found in some species of AM fungi, they are sac-like structures, emerging from hyphae, which serve as storage organs for lipids.
80% of plants

       
 
   

Other types of mycorrhizae do exist in nature but are specific to given families of plants Ex: orchids and the ericaceous families. The fungi involved in the mycorrhizal colonization of these plant families are currently not available in commercial products.

  
   
Arbutoid
All arbutus plants
Not obligate fungi 		Orchid
All orchid plants
Not obligate fungi
Orchids rely on them 		Ericoid
All EricacAll Ericaceous plants
(Blueberry, Azalea, Rhododendron)
Not obligate fungi
 
   
       

Ectomycorrhizae
Ectomycorrhizal fungi are also found in natural environments, mainly in forests ecosystems. These fungi can form visible reproductive structures (mushrooms) at the feet of trees they colonize. Ectomycorrhizal fungi grow between root cells without penetrating them. Their hyphae grow externally, forming dense growth known as a fungal mantle. These fungi form symbiotic relationships with most pines, spruces and some hardwood trees including beech, birch, oak and willow.
5 to 7% of plants

       
 
   
 
   

Mechanism of symbiosis

  
   

1-Spore germination

2-Root colonisation

   

3-Exploration

4-Network development

  
Back to top  
 
   

Mycorrhizal effects on soil structure

  

Soil structure refers to soil particle aggregation as well as pore spaces. Maintenance of soil structure is of critical importance to the preservation of soil functions and fertility. Mycorrhizal fungi play a major role in soil aggregation through hyphae networking and glomalin (biological glue) production. Therefore, their presence in the soil is essential to maintain physical soil properties. Better soil structure results in:

  
  • Greater water infiltration and water holding capacity
  • More permeability to air
  • Better root development
  • Higher microbial activity and nutrient cycling
  • Better resistance to surface sealing (crusts)
  • Better resistance to erosion (water/wind)
  • Better resistance to compaction
   
 
   

Production technology for high performance products

  
   

Premier Tech Biotechnologies has acquired over the years a unique expertise in industrial scale production of top quality mycorrhizal inoculants. The mycorrhizal production process developed by Premier Tech requires a strictly controlled environment and uses standards of the high-technology industry. This results in contaminant-free mycorrhizal spore suspensions that are used to formulate very high quality products.

  
   

Advantages of Premier Tech Mycorrhizae

  
   
  • Available in large quantities
  • Superior quality inoculants (Pathogen-free – Homogeneous - Consistent quality)
  • Great flexibility in formulation and applications
  • Can be formulated at different concentrations
  • Can be formulated with different carriers
  • Can be formulated according to customer’s needs
 
Back to top