INTERACTIONS BETWEEN ECTOMYCORRHIZAL NORWAY SPRUCE AND ERICOID MYCORRHIZAL EUROPEAN BLUEBERRY IN A MESOCOSM EXPERIMENT

FERNÁNDEZ NATALIA; VOHNÍK MARTIN; MESTRE MARÍA CECILIA

Praga

Congreso; 9th International Conference on Mycorrhizas (ICOM9); 2017

BACKGROUND: Ectomycorrhizal trees often co-occur with ericoid mycorrhizal shrubs, they may share certain root symbiotic fungi. Some of these shared fungi may be able to form both ectomycorrhizae and ericoid mycorrhizae (the Rhizoscyphus ericae aggregate). It is thus tempting to imagine that EcM and ErM plants are interlinked by the mycelium of these fungi (Common Mycorrhizal Networks). AIMS/HYPOTHESES: Ectomycorrhizal and ericoid mycorrhizal fungi are part of the same guild, hence prolonged co-cultivation of EcM spruce and ErM blueberry will lead to selection of fungi compatible with both host types (i.e., simultaneously forming mycorrhizae with both host types). These selected and shared fungi will dominate root systems of both hosts and form common mycorrhizal networks. RESULTS: For the first time, direct mycelial links were observed between ectomycorrhizae and ericoid mycorrhizal hair roots. However, the frequency of these links was extremely low (2-3 per pot). The linked ectomycorrhizae were formed by Cenococcum geophilum, but often hosted Meliniomyces bicolor as an endophyte. Presence of blueberry significantly increased mortality of spruce ectomycorrhizae. Mycorrhizal fungal guilds were well separated between spruce and blueberry with only a little overlap (Piloderma sphaerosporum). Ectomycorrhizae formed by Meliniomyces bicolor (i.e, the potentially shared fungus from the R. ericae aggregate) inhibited by blueberry. CONCLUSIONS: Direct mycelial links between spruce and blueberry extremely rare (C. geophilum EcMs!). Evident niche separation between EcM and ErM fungi (strong host preference). Blueberry inhibits the potentially shared Piceirhiza bicolorata ectomycorrhizae/the dual EcM/ErM fungus Meliniomyces bicolor. Blueberry negatively affects health status of spruce ectomycorrhizae.