Mycorrhizal symbioses are widespread and fundamental components of terrestrial ecosystems and have shaped plant evolution. Research in this field is rapidly evolving and recent findings have done much to improve our understanding of how these complex plant/fungal associations function. Providing either in-depth reviews or the results of previously unpublished scientific studies, the topics covered are of global interest and include plant/fungal communication, the interaction of mycorrhizal fungi with other soil microorganisms, the use of mycorrhizal fungi in plant-production systems, and the commercial harvesting of edible mycorrhizal forest mushrooms.