Page 68 - ACCB 2020

Revista de la Asociación Colombiana de Ciencias Biológicas
issn impreso 0120-4173, issn en línea 2500-7459
BENEFICIAL INTERACTION AMONGST AM sed seedling, shoot height, root dry weight, growth and
FUNGI AND OTHER ESSENTIAL MICROOR- phosphorus solubilization in tomato (Solanum lycoper-
GANISMS sicum L.) plant (74). AM fungi interact with phosphate
Interaction of AM Fungi with Symbiotic Nitrogen solubilizing microbes and enhance plant growth and
Fixers improved plant biomass (75). Inoculation of seedlings
The interaction between AM fungi and Leguminous with phosphate solubilizing bacteria such as Agrobac-
plants is reported to be synergistic; with improvement in terium sp. and Pseudomonas sp. or dual inoculations
nodulation and AMF colonization (61) The colonization maintained higher populations for longer durations in
of AM fungi increases the amount of fl avones (phyto- the mycorrhizal rhizosphere compared to non-myco-
elexins) in some leguminous plants, which increase the rrhizal roots, increased phosphorus uptake, increased
expression of nodulation gene (62). Further Rhizobium production of plant growth hormone and plant dry
produces extracellular polysaccharides which increases matter (76-77). Synergic interaction with AM fungi
the number of entry points per unit length of root. (63- and bacterial communities of mycorrhizosphere works
64). AM fungi and legumes-Rhizobium enhance plant as biostimulants and helps in enhancing plant growth,
growth with improvement in mineral nutrient and their plant health and plant nutrition by encompassing nitro-
ability to tolerate biotic and abiotic stress (environmen- gen fi xation and P solubilization (78).
tal stresses), which increase the rate of re-vegetation in
the semiarid ecosystem (65). Synergic interaction with Interactions of AM Fungi with helper mycorrhiza
AM fungi and Rhizobia works as biofertilizers and Some microorganisms known as MHO (Mycorrhiza
helps in reducing the root diseases by biological proces- Helper Organism) residing in the soil, can improve the
ses (66-67).Nodulation in Soyabean plant by AM fungi initiation of mycorrhizal symbiosis. These bacteria that
association helps maintain symbiotic N fi xation (SNF) are linked to the rhizosphere of the mycorrhiza, en-
2
under P scarcity (68). courages the growth of the fungus and aids mycorrhizal
colonization. Actinomycetes like Streptomyces coelico-
Interaction of AM Fungi with Asymbiotic Nitrogen lor (79) and fungus like Trichoderma harzianum also
Fixers facilitate colonization of AMF. Several workers have
Many of the free-living bacterial species of Azotobac- shown that inoculation of AM fungi in combination
ter, Azospirillium,Berijinckia, Clostridium, and Derxia with MHO improves the colonization of mycorrhiza,
are known to fi x atmospheric nitrogen (69). Studies re- growth of plant and yield. Bacteria that were isolated
veal that infection with mycorrhiza enhanced and main- from mycorrhizosphere (mycorrhizal roots or AMF’s
tained the levels of A. Chroococcum populations in the hyphae or spores) enhance the germination of AMF
rhizosphere and in return the spore production and co- spore and root colonization of AMF (80-82). This is
lonization by the mycorrhizal fungus were increased by due to the capability of certain bacteria to degrade in-
A. Chroococcum. Similar results were observed in pas- soluble biopolymers like chitin and chitosan, which are
palum and tall fescue on the interaction of A. Paspali major constituents of the AMF spore wall. The bacteria
with AM fungi and A. chroococcum with G. fascicula- living in the mycorrhizosphere and sporosphere enhan-
tum respectively (70). The interaction between Beije- ce the extension of extraradical mycelium (ERM), hen-
rinckia mobiles, Aspergillus niger and G. Fasciculatum ce acting as mycorrhiza helpers (83-84).
enhanced the growth of onion due to synergistic effects
of hormones produced on their mycorrhizal effi ciency Interactions of AM fungi with Neighbouring Plants
(71). AMF play a role in inducing biological interactions
among neighbouring plants. AMF grow an extensive
Interaction of AM Fungi with Phosphate solubilizers hyphal network below the soil in and around the roots
There exist certain environmentally friendly phosphate of the plants on which they grow. This network pro-
solubilizing microorganisms (PSM) which can be used vides a physical link between the soil and the roots of
as an alternative to chemical fertilizers (72). They are multiple host plants. The interaction by AMF with the
termed as phosphobacteria, they solubilize the unavai- neighbouring plants mediates plant-plant interactions
lable forms of phosphorus and provide it to the plant by facilitating the transfer of nutrients, carbon and water
(73). An experiment showed that the combination of ar- from one plant to another (9). Several studies demons-
buscular mycorrhizal fungi (AMF), phosphate-solubili- trate that AMF play a major role in nitrogen transfer to
sing bacteria (PSB) and phospho-compost (PC) increa- nearby plants or host plants (85). Interaction of cereals

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Rev. Asoc. Col. Cienc.(Col.), 2020; 32: 63-76