ROUTINE TRANSFORMATION OF RAPID-CYCLING CABBAGE (BRASSICA-OLERACEA) -MOLECULAR EVIDENCE FOR REGENERATION OF CHIMERAS

We have developed a transformation procedure using both disarmed and w ild-type Agrobacterium tumefaciens strains for a rapid-cycling cabbage genotype (Brassica oleracea var. capitata). This method is based on t he fact that the wild-type A. tumefaciens strain (82.139) can induce s hooty tumors in rapid-cycling cabbage. No special regeneration medium was required and no selection pressure was exerted at any stage of the transformation procedure; the transformants were identified by screen ing for beta-glucuronidase (GUS) activity with a histological assay. S outhern analyses ascertained that the GUS-expressing plants contained the T-DNA carried by the disarmed strain but not the T-DNA of the wild -type A. tumefaciens strain. One transgenic plant was obtained for an average of 25 plants inoculated. Southern analysis showed that most of the transgenic plants, under these non-selective conditions, proved t o be chimeric. Regeneration was established to be of pluricellular ori gin. The transgenic plants transmitted their T-DNA inserts to the prog eny.