Use of gibberelins and fertilizer sprays during the acclimatization of pineapple Smooth Cayenne c.v. ‘Serrana’ vitroplants

Abstract

In the last few years the productions levels of pineapple have decreased. The lack of planting material is one of the factors responsible for such a decrement. Two protocols for pineapple micropropagation have been recently developed: that described by Daquinta (1998), and the one of Escalona (1999). The first one uses conventional micropropagation methods, while the second one employs temporary immersion biorreactors. The critical step of these procedures is the acclimatization stage, because of the low survival and growth rates reaching the plants in this phase. The aim of this work was to evaluate the effect of gibberelins and fertilizer sprays on vitroplants growth. Doses of 0, 5, 100, 150 and 200 mg.l-1 of GA3 (BDH) were tested. Also three frequencies were evaluated: each 5, 10 and 15 days respectively. In a second experiment, four doses of the fertilizer Combi II were spayed on the plants: 0 (distilled water), 5,10 and 15 ml.l-1. Later, the combined application of GA3 and Combi II was measured compared to a control treatment (distilled water). Finally, the effects of GA3 (BDH) and the gibberelins produced by ICIDCA were compared. The sprays of GA3 (BDH) at 100 mg.l-1 twice a month, increased vitroplants growth; however, they caused undesirable morphological abnormalities of the plants. The sprays with the fertilizer Combi II at 5 mg.l-1 also improved plant growth. Its combined application with gibberelins (ICIDCA) at 100 mg.l-1 provoked an homogeneous and significant increment of plant growth. Key words: biotechnology, gibberelic acid, plant growth regulators