Trials were carried out in central Italy (Monsampolo del Tronto-AP) and in southern Italy (Pontecagnano-SA) (approval of the Italian Ministry of Health N° B/IT/97-29). The greenhouses were rather similar and made of galvanized steel and covered with plastic polyethylene (0.12 mm thick). An apparatus for drip-irrigation was used and the soil was completely mulched. A complete randomized block design with three replicate hybrid genotypes was adopted. Each experimental plot measured 3.12 m2 and contained eight plants in a double row. Transplanting was performed on March 3rd in southern Italy and on March 27th in central Italy. The P1, P2, P5, C1, C2 and the commercial Talina hybrids were employed. Transgenic parthenocarpic hybrids P1, P2 and P5 were obtained by crossing (as male parent) the primary transgenic plant DR2 iaaM #34-1 with the line Tal 1/1 (P1), the primary transgenic plant DR2 iaaM #28-1 with Tal 1/1 (P2) and the transgenic plant Tal 1/1 iaaM #1-1 with the line Tina (P5). The hybrids P1 and P2 are homologous to C1 (DR2 × Tal1/1), except for the presence of the DefH9-iaaM gene integrated in their genome. The transgenic hybrid P5 is homologous to its untransformed control C2 (Tal1/1 × Tina). DR2 and Tina are parental lines obtained through classical breeding, Tal1/1 is a double haploid line derived from anther culture of the F1 commercial cultivar Talina. The segregation of the marker gene nptII was checked by spraying the plants with kanamycin [14] and allowed for the conclusion that the transgenes segregate as a single locus in the backcrossed progenies of the three independent events analyzed (Tal iaaM 1-1: χ2 = 0.01065, P = 0.917; DR2 iaaM 34-1: χ2 = 0.0496 P = 0.824; DR2 iaaM 28-1 χ2 = 0.06467 P = 0.799). Southern blot analysis showed that DR2 iaaM 28-1 and 34-1 had a single copy of the transgene, while Tal iaaM 1-1 had three copies of the transgene (Fig 4). Since the interaction genotype/location was not significant for the yield, the data were computed as average of the two locations and subjected to analysis of variance according to a randomized complete block design. Duncan's Multiple Range Test (P = 0.05) was used for means separations.