Effect of NaCl and CaCl<sub>2</sub> on growth and contents of minerals, chlorophyll, proline and sugars in the apple rootstock M 4 cultured in vitro

Abstract

The apple (Malus domestica Borkh) rootstock M 4 shoots were grown in vitro for 4 weeks on Murashige and Skoog (MS) medium containing three NaCl concentrations (35, 100 and 200 mM) in combination with two CaCl2 concentrations (5 and 10 mM). Inclusion of 10 mM CaCl2 in the medium, in the presence of 35 mM NaCl, significantly increased the number of shoots and the fresh mass compared to 5 mM CaCl2. The number of shoots, length of shoots, and the fresh mass of cultures were very low in the presence of 100 and 200 mM NaCl, independently of CaCl2 concentration of the medium. By increasing NaCl and CaCl2 concentrations in the culture medium, contents of N, Na, Cl, proline and soluble sugars in plantlets increased, whereas K, Mg, B, Zn and chlorophyll content decreased in comparison to the control.