BERTINI, LUANA1, DEBORAH AGOSTINI1, LUCIA POTENZA1, ISMAELA ROSSI1, SABRINA ZEPPA1, ALESSANDRA ZAMBONELLI2 & VILBERTO STOCCHI1.
1Istituto di Chimica Biologica "Giorgio Fornaini", Università di Urbino, via Saffi, 2 - 61029 Urbino (PS) - ITALY. 2Dipartimento di Protezione e Valorizzazione Agroalimentare, Università di Bologna, via Filippo Re, 8 - 40126 Bologna - ITALY.
Five species of white truffle, Tuber magnatum, T. borchii, T. maculatum, T. dryophilum, T. puberulum, were studied in order to identify species-specific markers. PCR-based techniques allowed the identification of two SCAR (Sequenced Characterized Amplified Region) markers specific for T.borchii. The first pair of SCAR primers, TBI/TBII, was designed from the sequence of one RAPD (Random Amplified Polymorphic DNA) fragment, T438, which was common to Tuber borchii and absent in the other species. Among the species under study, this SCAR marker amplified an internal fragment of 363 bp in length only from genomic DNA of T. borchii. The other pair was derived from regions flanking the 5'-3' ends of tb 11.9, a gene overexpressed in T. borchii fruitbody and cloned from the mycelium of this species. These designed primers, EST1/EST2 amplified a region of 699 bp which was present in T. borchii samples. The use of SCAR strategy allowed the identification of Tuber borchii species in a single PCR reaction during all the phases of its life cycle: fruitbody, mycelium, mycorrhiza. Moreover it also represents a powerful tool to evaluate the presence of the selected symbiontic fungus in mycorrhized seedlings.
Key words: RAPD/PCR fingerprint - SCAR marker - Tuber borchii (white truffle) - mycelium ectomycorrhiza.