Abstract: Foreign genes were introduced into the hypocotyl protoplasts of Brassica oleracea L. by means of PEG treatment. With hygromycin and kanamycin resistance as selection markers, resistant calli were successfully recovered. For hygromycin resistant calli, the absolute and relative transformation frequencies were 4.1 x 10-4 and 1% ~ 3% respectively. Then, the resistant calli were transferred onto differentiation medium for shoot induction. After the regenerated shoots were rooted on rooting medium, they were transplanted in pots. Most of the transplants grew well. Southern blotting analysis showed that foreign genes have been integrated into plant genomes. Some factors influencing the transformation frequencies were discussed.Foreign genes were introduced into the hypocotyl protoplasts of Brassica oleracea L. by means of PEG treatment. With hygromycin and kanamycin resistance as selection markers, resistant calli were successfully recovered. For hygromycin resistant calli, the absolute and relative transformation frequencies were 4.1 x 10-4 and 1% ~ 3% respectively. Then, the resistant calli were transferred onto differentiation medium for shoot induction. After the regenerated shoots were rooted on rooting medium, they were transplanted in pots. Most of the transplants grew well. Southern blotting analysis showed that foreign genes have been integrated into plant genomes. Some factors influencing the transformation frequencies were discussed.

Key words: Brassica oleracea, Protoplasts, PEG-mediated gene transfer, Transgenic plant