EN
Preliminary investigations were carried out on the transformation of high susceptibility tobacco cultivars. The plants were transformed by being infected with Agrobacterium tumefaciens with binary PROK2- derived plasmids carrying a PVY casette in the sense and antisense orientations and with a plasmid carrying the lettuce mosaic virus (LMV) coat protein gene. Kanamycin resistant plants were obtained following transformation. PCR testing of a selected group of regenerants revealed the presence of a transgene. Disease symptoms were absent from 52% of transgenic plants inoculated with PVYN. This was confirmed by ELISA values.In the T1 generation of transgenic plants, 510 (78%) showed no symptoms after inoculation and 155 (22%) showed typical PVYN symptoms. Among 510 symptomless plants 213 (36%) were selected as highly resistant, 207 (31%) as partially resistant and 89 (11%) as tolerant. Forty kanamycin resistant plants of T2 generation were tested with PVYN. Two plants showed vein necrosis, five - vein clearing and 33 plants showed no disease symptoms. ELISA tests allowed to identify 33 plants (84,6%) totally resistant to PVYN. The preliminary data reported here showed more resistant plants in T2 generations.