Micropropagação de Dyckia maritima Baker - Bromeliaceae

Abstract

The species Dyckia maritima Baker represents a safe alternative of ornamental bromeliad, cause it does not retain pluvial waters, in this way, it does not proliferate mosquitos transmitters of the malaria. The aim of this work was to develop a protocol to in vitro propagate D. maritima species. The specific objectives were to evaluate the effects of the ammonium nitrate (NH4NO3) in the multiplication and regeneration of adventicious buds, to develop a culture medium for the elongation phase of the sprout, to promote in vitro rooting and to develop a hidroponic system to promote acclimatization. Plântulas of 25 days were cultivated in the same concentrations of BAP and AIB (0; 0.5; 1.0 or 3.0mg L-1), and then with a reduction for 0,1mg L-1 of AIB to induce basal adventicious buds. Buds were multiplied on the influence of KIN or BAP (0; 0,1; 0,22 or 0,45mg L-1) and regenerated in sprouts, which were taken root in 0,1mg L-1 of AIB. In buds agrupamentos explants, concentrations of ammonium nitrate were tested (0; 0,1; 0,25; 0,5 or 1,0g L-1) with the presence or absense of 0,22mg L-1 of KIN. The elongation of the agrupamentos sprouts, concentrations of MS medium (25, 50 and 100%) and of GA3 (0; 0,1; 0,25; 0,5; 1,0; 2,0; 3,0; 4,0 or 5,0mg L-1) were tested. The acclimatization was made in a hydroponic system, the nutritious solution was the MS medium without sucrose. The equals concentrations of BAP and AIB didn't demonstrate significant differences. KIN was the cytokinin that provided larger multiplication and regeneration of the buds. The ammonium nitrate without the presence of 0,22mg L-1 of KIN demonstrated to produce effects similar of the citocinines. The medium for the elongationn phase that promotes sprouts with the largest lengths is the MS with 100% of the salts supplemented with 2,6mg L-1 of GA3. It was possible to acclimatize the D. maritima species after 30 days in this hydroponic technique, Substrate is necessary to reduce the percentage of mortality. The coconut fiber used as substrate allowed the survival of 80% of plantlets.