Genetic transformation of major wine grape cultivars of Vitis vinifera L.

We have developed an Agrobacterium-mediated transformation system for a number of important grapevine cultivars used in wine production. Transgenic plants were obtained for the seven cultivars: Cabernet Sauvignon, Shiraz, Chardonnay, Riesling, Sauvignon Blanc, Chenin Blanc and Muscat Gordo Blanco. Embryogenic callus was initiated from anther filaments and genotypic differences were observed for initiation and subsequent proliferation with Chardonnay responding most favourably to culture conditions. The transformation system allowed the recovery of germinating transgenic embryos 10-12 weeks after Agrobacterium inoculation and plants within 18 weeks. Examination of the expression patterns of the green fluorescent protein gene under the control of the CAMV35S promoter in leaf tissue of transgenic plants showed that for up to 35% of plants the pattern was not uniform. The successful transformation of a genetically diverse group of wine grape cultivars indicates that the transformation system may have general application to an even wider range of Vitis vinifera cultivars.