Effect of Salinity on Shoot Concentration of Trace Elements in Different Citrus Species

The Effect of various NaCl levels on the shoot content of trace elements, in the seedlings of five citrus species namely: Bakraei (Citrus reteculata X C. limetta), Volkamer lemon(C. volkameriana), Sour orange(C. aurantium), Sweet lime (C. limetta) and Mexican lime(C. aurantifolia), were studied in a glasshouse, by a randomized complete block design with factorial arrangement and four replications. One-year old seedlings of each species were grown in the 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, the amount of Fe, Zn, Mn, Cu, Cl and B in shoots were determined. The amount of trace elements varied among the species even in the control plants (no salt). Salinity had different effects on the shoot content of trace elements. Salinity reduced Fe content in the shoot of all species except in Bakraii and sweet lime and increased the amount of Zn in the shoot of all species except in Bakraii. The Mn content was reduced in the all species but increased in sour orange. Salinity reduced the amount of Cu in the shoot of volkamerina but had no effect in the other species. The amount of Cl increased in the shoot of all species with salinity. Boron content in the shoot of all species except in sour orange, increased with low salinity level but decreased with increased salinity levels. However in sour orange, salinity in the all levels decreased the amount of B in the shoot of seedlings.