[1] Univ Naples Federico II, Dipartimento Arboricoltura Bot & Patol Vegetale A, I-80138 Naples, Italy
[2] Cornell Univ, New York State Agr Expt Stn, Dept Hort Sci, Geneva, NY 14456 USA
[3] Univ Salamanca, Dept Genet & Microbiol, Ctr Hispano Luso Invest Agr CIALE, E-37008 Salamanca, Spain