Mycorrhization of Quercus robur L., Quercus cerris L. and Corylus avellana L. seedlings with Tuber macrosporum Vittad.

Tuber macrosporum Vittad. is not a common truffle species, but with remarkable organoleptic qualities and much economic interest. After the addition of truffle spore slurry, 30 seedlings of Quercus robur L., Quercus cerris L. and Corylus avellana L. were grown inside a greenhouse for 11 months before evaluation of the mycorrhizal level. Two different potting mixes were used: a natural soil-based potting mix for Q. robur, Q. cerris and C. avellana and a peat-based potting mix for Q. robur. Quercus robur planted in soil potting mix was the most receptive towards the truffle spore inoculum, with a level of formation of T. macrosporum ectomycorrhizas (ECMs) of approximately 14 %, ranging from a minimum of similar to 4 % to a maximum of similar to 44 % in different seedlings. No T. macrosporum ECMs developed on Q. cerris (soil potting mix) or on Q. robur (peat potting mix), whereas a low percentage of ECMs was detected on only three C. avellana (soil potting mix) seedlings. The fungus Sphaerosporella brunnea (Alb. & Schwein.) Svrek & Kubika was also detected as a contaminant on almost half the truffle-inoculated seedlings. A new detailed description of the morphological and anatomical characteristics of T. macrosporum ECMs and their DNA-based verification with species-specific markers were also reported.