Micro Nutrients Concentrations Changes in Different Citrus Species Root Under Salinity Stress

Effects of four NaCl levels on root concentration of micro nutrients, in seedlings of five citrus species namely: Bakraei (Citrus reteculata × C. limetta), Volkamer lemon (C. volkameriana), Sour orange (C. aurantium), Sweet lime (C. limetta) and Mexican lime (C. aurantifolia), were studied in greenhouse, using a factorial experiment in randomized completely design with four replications. One-year old seedlings of each species were grown in pots, containing native soil (pH=8.2) and irrigated with water supplemented with 0(control), 20, 40 and 60 mM NaCl. At the end of experiment, concentration of Fe, Zn, Mn, Cu, Cl and B in roots were determined. The concentration of micro nutrient varied among species even in control plants(no salt). Salinity had different effects on root concentration of micro nutrient. Under salinity stress Fe concentration was reduced in all species roots except in Mexican lime and sour orange and increased the concentration of Zn in species roots except in Bakraei. Salinity increased the concentration of Mn in all species roots and reduced the concentration of Cu and B except in Bakraei. The concentration of Cl increased in all species roots with increased salinity level.