In vitro rooting improvement of globe artichoke (cv. Camus de Bretagne) by GA3

Microrosettes of globe artichoke (Cynara scolymus L.) were subcultured in a medium with naphthalene acetic acid and kinetin. For rooting, shoots were placed on an auxinic rooting medium (2.68 mu M naphthalene acetic acid) supplemented with or without gibberellic acid (GA(3)). Treatments with 2.9 and 14.4 mu M GA(3) resulted in 80.5 and 92.3% root formation, respectively, whereas 28.8 mu M GA(3) did not significantly change the rooting rate produced by auxin alone (50%). Moreover, the number of roots per shoot significantly increased for plants grown on rooting media containing 2.9 and 14.4 mu M GA3. Stimulation by GA(3) of rhizogenesis was accompanied with a large increase of leaf growth. (C) 1997 Elsevier Science B.V.