Temporal dynamics of ectomycorrhizal community composition on root systems of oak seedlings infected with Burgundy truffle.

Truffles, the hypogeous ascocarps of the ectomycorrhizal genus Tuber, are currently cultivated in orchards to partially offset declining wild production in Europe. Truffle cultivation begins with inoculation of seedling root systems in the greenhouse. Once the mycorrhizal relationship is well established, colonized seedlings are transplanted to a suitable field site. In the USA, little is known about the effect of indigenous ectomycorrhizal species on colonization of host trees by the European Burgundy truffle fungus (T. aestivum). Here we identify the ectomycorrhizal community composition on inoculated seedlings grown in the greenhouse in three types of potting media. We subsequently monitored the ectomycorrhizal community composition for two years after seedlings were transplanted into a field site that had been prepared for truffle cultivation by lime applications. We found that the infection rates of contaminant ectomycorrhizal species present in the greenhouse declined to low levels in this field site. We also found that after two years in the field, both T. aestivum colonization levels and indigenous ectomycorrhizal species richness and abundance increased, indicating that indigenous species, in the short term, did not displace T. aestivum.