Effect of spermidine on ornamental bromeliad cultured in vitro
Plants of the ornamental bromeliad, Aechmea blanchetiana (Baker) L.B. Smith obtained from seeds germinated in vitro, were treated with spermidine (Spd) at various concentrations (0, 10, 50 and 250 μM) or in the presence of 1.07 mM α-naphthaleneacetic acid (NAA) + 22.20 mM 6-benzyladenine (BA) or 0 mM NAA + 0 mM 6-BA for shoot induction and 0, 1.07 and 5.37 mM of NAA for root induction. The number of shoots, fresh and dry weight of shoots on shoot induction and fresh and dry weight of shoots and roots on root induction, and activity of peroxidases were evaluated. Polyamine Spd was not effective on shooting induction, rooting, mass accumulation of fresh and dry weight and had no influence on the activity of the enzyme peroxidase, and had a deleterious effect on dry matter accumulation in the treatment for shooting induction. Spd improved the qualitative and quantitative responses of in vitro rhizogenesis of A. blanchetiana as compared to the free polyamine medium. Peroxidase activity was higher in leaves of plants subjected to shoot induction, with 6-BA+NAA. The exogenous spermidine did not have effect on peroxidase activity.
Keywords: Bromeliad, micropropagation, peroxidase activity, polyamine