Figure. 1 - Abundance of various types of mycorrhizas among plant species, literature review based on 128 publications (Brundrett, 2009) including approximately 8,000 plant species, AM – arbuscular mycorrhizas, EcM – ectomycorrhizas, NM – non-mycorrhizal, Ericoid – ErM, Orchid – OrM.Arbuscular mycorrhizasThe most common and abundant mycorrhiza is AM which belongs to the endomycorrhizas and is notably associated with approximately 74% of all angiosperm plant species, a number of gymnosperm species and to certain cryptogamic species (Brundrett, 2009). AM is formed solely by an obligate mycorrhizal fungal clade called Glomeromycota. AMf and are generalists and form a mycorrhizal symbiosis with various plant species. Glomeromycota have been vitally dependent on their autotrophic hosts since the beginning of plant evolution. Some authors support a theory according to which mycorrhizal fungi allowed plants to leave the aquatic environment and colonize the soil (Selosse & Le Tacon, 1998). Colonization of plant root cells by AM fungi begins with attraction by strigolactone molecules released by the plant. roots (Besserer et al., 2006) and then continues with a cascade of signals induced by fungal hyphae and gradually leads to the penetration of plant cortical cell walls (Oldroyd et al., 2005). Plants recognize AMf as a mutualistic organism and allow it to enter their living cells. The plasma membrane of the penetrated root cells remains intact and covers the entire surface of the fungal hyphae which gradually form a typical tree-like structure called an arbuscule. The branched structure of the arbuscule builds a highly multiplied surface area between the fungal and plant phospolipid membranes, resulting in the formation of a space called the interfacial matrix...... middle of paper ...... representatives form a mutualistic symbiosis with EcMf, AMf and Actinobacteria (Benson & Clawson, 2000). Another example is EcM Quercus ilex from the family Fagaceae in whose roots ErMf can also be found but they do not form ErM (Bergero et al., 2000). The typical anatomical feature of EcM is the fungal intercellular structure called Hartig net, hyphal leaf covering the outer surface of the host plant roots and emitting mycelial hyphae capable of creating more complex structures called rhizomorphs (Peterson et al., 2004). Mycelial hyphae and rhizomorphs significantly increase the surface area and radius of the entire root and mycorrhizal system and allow it to reach further (Anderson & Cairney, 2007) and acquire more nutrients from the soil. The nutrients provided by EcM fungi for its host plants are, as mentioned, P and mainly N, amino acids, enzymes, water, etc...