Treatment of arbuscular mycorrhizal mushroom (AM mushrooms) comprises contacting AM mushrooms with at least a stimulating agent (e.g. sorgolactone, demethylsorgolactone, alectrol, strigol and orobanchol) to stimulate the development and/or the growth of the AM mushrooms. Treatment of arbuscular mycorrhizal mushroom (AM mushrooms) comprises contacting AM mushrooms with at least a stimulating agent (3-(4-methyl-5-oxo-2,5-dihydro-furan-2-yloxymethylene)-3,3a,4,8b-tetrahydro-indeno[1,2-b]furan-2-one (GR24)； 3-(4-methyl-5-oxo-2,5-dihydro-furan-2-yloxymethylene)-3,3a,6,6a-tetrahydro-cyclopenta[b]furan-2-one (GR7)； nijmegen 1； demethylsorgolactone； sorgolactone； alectrol and its isomer； strigol； and orobanchol) to develop and/or grow AM mushrooms. Independent claims are also included for: (1) production of arbuscular mycorrhizal mushroom inoculums (AM mushrooms) comprising a coculture of AM mushrooms in the presence of living vegetable matter (host plant) and contacting the coculture with the stimulating agent/pollinating agent to stimulate the development and/or the growth of the AM mushrooms； (2) cultivation process of a host plant capable of forming a symbiosis with the arbuscular mycorrhizal mushrooms, comprising cultivating a soil by an addition of the stimulating agent during the sowing of grains of the host plant to be cultivated and/or subsequently to the sowings； and (3) composition (A) comprising combination of seeds of the host plant capable of forming the symbiosis with the AM mushrooms or AM mushroom inoculum, and the stimulating agent for the development and/or the growth of AM mushrooms.
