Methodologies for in Vitro Cultivation of Arbuscular Mycorrhizal Fungi with Root Organs

Themonoxenic cultureof arbuscularmycorrhizal (AM) fungi hasmarkedly improved our understanding of the symbiosis. In the past 15 years, increasing amounts of literature have been devoted to this intimate plant–fungal association using various AM fungi in vitro cultivation systems, with different hosts, AM fungal propagules and growth media. The proportion of papers published using either in vitro, axenic, monoxenic, root organ culture or ROC as keywords, relative to the overall literature dealing with AM fungi (ISI web of Science http://www.isinet.com)4, was less than 1% in the years 1987–1989, increasing to approximately 5% in the subsequent 6 years (1990–1995), to reach a plateau at 8% from 1996 to present. The invariable proportion between papers using AM fungi in vitro systems and complete literature on AM fungi since 1996 until today suggests that the use of this system still remains in the hands of a limited number of researchers, and that new progress is necessary to reach a broader audience. If one agrees that the axenic culture of AM fungi remains the major challenge at the start of this new millennium, the present diffusion of clear protocols on AM fungi in vitro culture techniques may render this technology more widely accessible and secure its broad and reliable dissemination. Indeed, as stated byBago andCano (seeChap. 7) . . . “AM(fungi)monoxenics are far