Effect of nitrogen, phosphorus and calcium on in vitro growth and development of Aechmea blanchetiana

This study aimed at evaluating the effects of different levels of nitrogen (N), phosphorus (P) and calcium (Ca) in MS medium (Murashige and Skoog, 1962) on in vitro growth of Aechmea blanchetiana seedlings. Five different molar concentrations were used for each macroelement and attention was paid to maintain the ionic balance: (1) for N: 7.5, 15, 30, 60 or 120 mM; (2) for P: 0.15, 0.30, 0.60, 1.25 or 2.50 and (3) for Ca: 1.5, 3.0, 4.5, 6 or 12 mM. The different concentrations of N and Ca did not affect the dry weight of the A. blanchetiana microshoots while increased P levels enhanced the productivity. Microelement content in microshoot leaves could be affected by the macroelements supplied to the culture medium. Cu and Fe increased and B, Mn and Zn decreased in leaves of A. blanchetiana microshoots with increasing N levels in the medium. High levels of P reduced Zn, Cu and Fe concentrations in leaves (antagonism), whilst B remained constant with increasing levels of P in the modified MS medium. The concentrations of Mg, Fe and Zn decreased (antagonism), whilst the concentrations of B and Cu were constant with increasing levels of Ca in the modified MS medium. Our results show the dynamics of the synergism or antagonism of N, P and Ca elements in the MS liquid medium on micronutrients levels in leaves of A. blanchetiana.