Regeneration ability and Agrobacterium-mediated transformation of different cultivars in Brassica oleracea L. and B-rapa L. (syn. B-campestris L.)

Genetic transformation in Brassica vegetables, especially cabbage (B. olera cea L. var. capitata) and Chinese cabbage (B. rapa L. (syn. B. campestris L .) ssp. pekinensis), has been difficult, probably because of their low rege neration ability in tissue and cell culture. Varietal differences in the re generation ability were examined among 36 cultivars of B. oleracea and B. r apa in tissue culture. We found a wide varietal difference in the frequency of shoots regenerated from hypocotyls and cotyledonary petioles. Using 11 cultivars with high regeneration ability and 5 doubled haploid (DH) lines d erived from 2 cultivars, transgenic plants were obtained from 7 cultivars a nd 3 DH lines. The transformants were confirmed by histochemical beta -gluc uronidase gene activity and PCR analysis. From these results, we believe Ag robacterium-mediated transformation can be effectively applied for breeding of Brassica vegetables.