Interactive effects of salinity and magnesium on water and ionic relations of Zygophillum fabago L.

In order to investigate the interaction effects of salinity and magnesium on growth, physiological characteristics and content of some nutrients in Zygophyllum fabago plants, a factorial experiment designed and was carried out in perlite with Hoagland solution. The treatments consisted of two levels of salinity (0 and 300 mM) and three levels of 0, 2 and 6 mM magnesium over on magnesium content in Hoagland (2 mM). The application of magnesium in saline conditions led to an increase in the dry weight of the shoot over two times of control (55 g D.W.) and root over 30%. Salinity increased leaf water content. While the salinity and magnesium interaction led to a relative decrease in LWCA near the control amount about 400 g H2O2 m-2. Salinity and its interaction with magnesium led to a negative effect of osmotic potential of leaves, which was a more negative contribution of sodium in saline treatments than control, but the interaction effects decreased significantly contribution of potassium to osmotic potential. Salinity and magnesium reduced the amount of calcium, magnesium and potassium and increased the sodium content of the Zygophyllum organs. It seems that adding the appropriate amount of magnesium to the growth medium can improve plant growth under saline conditions by introducing appropriate changes in the absorption and accumulation of other elements. Also, high concentration of sodium in its leaves directly used for osmotic regulation, which reduces the leaf water potential, improves the leaf water condition and thus improves growth.