RolC-transgenic carnation with improved horticultural traits: Quantitativeand qualitative analyses of greenhouse-grown plants

Expression of the rolC gene under the constitutive CaMV 35S promoter led to several advantageous alterations in transgenic carnation (Dianthus caryoph yllus L, 'White Sim'). The rolC transgenic carnation plants exhibited incre ased axillary budbreak and development when grown under standard commercial greenhouse conditions. Carnation with rolC generated up to 48% more stem c uttings per mother plant than nontransformed plants. Stem cuttings from rol C plants exhibited better rooting ability, with up to five times higher roo t dry weight than controls. The improved rooting of rolC-transgenic stem cu ttings was also apparent when the cuttings were treated with IBA, During th e flowering season, rolC-transgenic plants produced up to three times more flowering stems than control plants. It should be noted that the latter alt erations, namely increased flowering and rooting, are of major importance t o the carnation industry. Chemical name used: indole 3-butyric acid (IBA).