Regeneration and transformation of some cultivars of headed cabbage

The efficiency of adventitious shoot organogenesis in some widely used cult ivars of headed cabbage (Brassica oleracea var. capitata L.) was investigat ed at various culture media. The optimal conditions for production of trans genic plants of these cultivars were determined. The regeneration frequency depended on the composition of the medium and gel-forming substances. Silv er nitrate and gibberellic acid had no appreciable effect on the frequency of shoot regeneration. In four cultivars, a regeneration frequency of nearl y 100% was obtained. The transformation of plants was accomplished using tw o different strains of Agrobacterium tumefaciens bearing the DK335 construc t. The DNA of this construct was composed of binary vector pBIN19, the mark er gene nptII, and the gene coding for capsid protein of potato virus Y (PV Y-cr), which was cloned between the 35S promoter and the polyadenylation si te. Transgenic plants of the cultivars Erdeno, Kalorama, and Krautman were obtained with a transformation frequency of 2-3%. The integration of the in troduced genes nptII and PVY-cr into regenerated plants was revealed by pol ymerase chain reaction and Southern blot hybridization. Factors affecting t he transformation frequency are discussed.