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

We have recovered transgenic chrysanthemum plants on a medium containi ng hygromycin after Agrobacterium-mediated transformation. We used the disarmed hypervirulent strain EHA101 containing a binary vector carry ing the neomycine phosphotransferase II, the glucuronidase (GUS) and t he hygromycin phosphotransferase genes. Different protocols of transfo rmation are discussed. Optimal conditions were inoculations of nodes ( dropping 20 min in the bacterial suspension) which were immediately tr ansferred 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. DN A analysis of plants showing GUS expression confirmed the T-DNA integr ation in the plant genome.