EFFECTS OF SOME PLANT-GROWTH REGULATORS ON THE GROWTH OF THE SEAGRASSCYMODOCEA-NODOSA (UCRIA) ASCHERSON

The effect of three auxins (indole-3-acetic acid, alpha-naphthaleneace tic acid, 2,4-dichlorophenoxyacetic acid), three cytokinins (6-furfury laminopurine, 6-benzylaminopurine, 6-(gamma-gamma-dimethylallylamino)p urine) and one gibberellin (gibberellic acid) at external concentratio ns from 0.01 to 10 mg l(-1) on the leaf and rhizome growth of fragment s of the seagrass Cymodoceanadosa (Ucria) Ascherson was assessed in th e laboratory. Only the treatment with gibberellic acid showed a dose-d ependent positive effect on leaf growth at external concentrations bet ween 0.01 and 10 mg l(-1). Rhizome growth, however, was higher (P < 0. 05) at 0.01-0.1 mg l(-1) and decreased with increasing external concen trations of gibberellic acid.