RECOVERY OF TRANSGENIC CHRYSANTHEMUM (DENDRANTHEMA-GRANDIFLORA TZVELEV) AFTER HYGROMYCIN RESISTANCE SELECTION

We have recovered transgenic chrysanthemum plants on a medium containing hygromycin after Agrobacterium-mediated transformation. We used the disarmed hypervirulent strain EHA101 containing a binary vector carrying the neomycine phosphotransferase II, the glucuronidase (GUS) and the hygromycin phosphotransferase genes. Different protocols of transformation are discussed. Optimal conditions were inoculations of nodes (dropping 20 min in the bacterial suspension) which were immediately transferred on a regeneration medium containing cefotaxime (500 mug/ml) and hygromycin (10 mug/ml). Neoformation of buds occurred on selective medium within two months on almost 40% of the inoculated explants. DNA analysis of plants showing GUS expression confirmed the T-DNA integration in the plant genome.