studying the possibility of in vitro cultivation of three arbuscular mycorrhizal fungi species

the most important limiting factor for mass production of mycorrhizal fungi inoculums and subsequently their use in arable soil is obligate nature of this symbiosis. to overcome this problem, several methods such as hydroponic ,aeroponic, and root organ culture have been proposed for spore production of these fungi. each of these methods has several capabilities and limiting factors.  the goal of this research were in vitro production of three species of mycorrhizal spores. in the first stage, attempt was made to produce induced roots by inoculating three strains of agrobacterumrhizogenesto and using sterile carrot disks. results showed that, from the inoculated tissues, induced roots developed on carrot. due to genetic stability, induced roots from carrot disks were used for next stages of this project. spores of three species of arbuscular mycorrhizal fungi including glomus intraradices, glomus etunicatum and glomus mosseae were prepared by trap culture of sudan grass, isolated from soil and disinfected by proper antibiotic compounds. these spores were placed near the head of induced carrot roots on m medium in sterile condition. after establishment of symbiotic relationship between these two organisms for spore production, the colonized roots were transferred to 250 ml glass bottle with 100 ml of m medium. after 8 weeks, roots and fungi were isolated from medium. results of this project showed that in vitro culture was an effective method for spore production of glomus intraradices and glomus etunicatum. but, glomus mosseae did not produce any spore by this method and we suggest that other methods, such as aeroponic and hydroponic, be used for spore  production of this fungus