IN-VITRO ROOTING IMPROVEMENT OF GLOBE ARTICHOKE (CV CAMUS-DE-BRETAGNE) BY GA(3)

Microrosettes of globe artichoke (Cynara scolymus L.) were subcultured in a medium with naphthalene acetic acid and kinetin. For rooting, sh oots were placed on an auxinic rooting medium (2.68 mu M naphthalene a cetic acid) supplemented with or without gibberellic acid (GA(3)). Tre atments with 2.9 and 14.4 mu M GA(3) resulted in 80.5 and 92.3% root f ormation, respectively, whereas 28.8 mu M GA(3) did not significantly change the rooting rate produced by auxin alone (50%). Moreover, the n umber of roots per shoot significantly increased for plants grown on r ooting 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.