Kurita et al. 2015 (Conference Paper) Alcantarea

Growth in vitro and ex vitro of bromeliad Alcantarea imperialis (Carrière) Harms in different concentration of ammonium

Author(s):—F.M.K. Kurita, S.G. Santos & V. Tamaki in Benko-Iseppon, A.M.; Alves, M. & Louzada, R. (2015) An overview and abstracts of the First World Congress on Bromeliaceae Evolution. Rodriguésia 66(2): A1-A66.

Publication:— (2015).

Abstract:—Alcantarea imperialis is a bromeliad used in landscaping and is endemic of Serra dos Orgãos/RJ/BR, making conservation measures are necessary, for which in vitro and ex vitro cultures could be tools. An important aspect of in vitro culture is the mineral supply of the culture medium. Nitrogen (N) is the main component of amino acids, nucleic acids, chlorophyll and coenzymes and one of its sources is ammonium (NH4+). Thereare no studies for this plant comparing in vitro and ex vitro culture with different NH4+ concentrations. This study aimed to compare the in vitro and ex vitro growth of plants of A. imperialis with four NH4+ concentrations. Plantlets germined in vitro and ex vitro were transferred to the culture conditions (culture medium or Pinus sp. bark substrate). The culture medium used was Murashige and Skoog (MS) modified with different concentrations of NH4+ (5, 15, 30 and 60 mM), supplemented with 3% sucrose, 0.1 mg L-1 of thiamine-HCl, 100mg L -1 of myo-inositol and 5 g L-1 of agar with pH adjusted to 5.8. Each in vitro treatment had five vessels of 10 seedlings each. In the ex vitro conditions, plants were fertilized weekly with of MS medium solution (50 ml) described above (but without sucrose and agar). Cultures were maintained in a growth chamber at 26±2°C and 30 µmol m-2 s-1 light photons provided by cold white lamps during 12 hours of light regime. After three months, length of the longest root, number of leaves and length of the shoots were determined, besides amounts of fresh and dry weight of both roots and shoots, as well as the quantity of photosynthetic pigments in both group of plants. The results showed that the in vitro cultivated plants grew more than the ex vitro ones, but at a concentration of 60 mM ammonium plants did not show favorable growth in vitro. In conclusion, ammonium at high concentrations proved to be toxic to this species under in vitro culture.

Keywords:—Bromeliaceae; Nitrogen; Threatened with Extinction.