Excellent recommendation from Hani Antoun! Since centuries the direct growth of AM fungi has been tried, but no success could be achieved due to the obligate biotrophic development of these symbionts. But the germination process can be studied on suitable media. Also the infection process can be followed on these media with transformed root cultures - but the techniques is rather laborious. I also recommend the literature (published by Springer) from Declerck S., Strullu D.-G., Fortin J.A. 2005: In vitro culture of mycorrhizas. Good luck!
This might be fungi like Piriformospora indica - but these do not belong to the Glomales. These are root inhabiting endophytes - not "true" AM fungi. - But I like to learn more about anything new - so agree with Johannes Wöstemeyer, please let us know, which Genera and species you mean - thanks in advance! HWD