GENETIC-TRANSFORMATION AND REGENERATION OF TRANSGENIC PLANTS IN GRAPEVINE (VITIS-RUPESTRIS S)

Isolated somatic embryos from petiole-derived callus cultures of Vitis rupestris Scheele have been employed in experiments on genetic transformation. Co-cultivation of somatic embryos during embryogenesis induction with Agrobacterium tumefaciens strain LBA4404, which contains the plasmid pBI121 carrying the neomycin -phosphotranspherase and the beta-glucuronidase genes, produced transformed cellular lines capable of recurrent somatic embryogenesis. Precocious selection for high levels of kanamycin (100 mgl(-1)) was an important part of our transformation protocol. Transformed lines still have strong beta-glucuronidase expression as well as stable insertion of the marker genes after 3 years of in-vitro culture, during which they have maintained their capacity to organize secondary embryos and to regenerate transgenic plants with an agreeable efficiency (13%).