Journal of Plant Process and Function

In the present study, response of Pistachio (Pistacia vera L.) on nitrate reductase activity, some biochemical characters and ions accumulation to salinity were evaluated. Salinity treatments (0, 75, 150 mM NaCl) and potassium nitrate (0, 10, 15 mM) were imposed and sampling were done 100 days after treatments. Results indicated that sodium chloride at 75 mM plus 10 mM potassium nitrate resulted in the greatest nitrate reductase activity in leaf of salt-stressed plants and sodium chloride at 150 mM plus 10 mM potassium nitrate or sodium chloride at 150 mM resulted in the least nitrate reductase activity, and nitrate reductase activity did not differ in other treatments. Salt-stressed plants treating potassium nitrate (10 or 15 mM) had higher leaf nitrate content than those not treated with potassium nitrate. Potassium nitrate significantly increased root nitrate content in salt stressed plants. Total amino acids in leaf decreased with NaCl treatments, but this was not the case for the plants treated with 75mM NaCl without potassium nitare. At each salinity treatment, addition of 10 or 15 mM potassium nitrate reduced total amino acids in roots of pistachio seedlings. The contents of sodium (Na⁺), potassium (K⁺) and chloride (Cl^-) were significantly affected by sodium chloride treatments as well as the potassium nitrate treatments. The results suggested that the nitrate uptake and assimilation in leaf or root of pistachio seedlings were significantly affected by continuous applied of potassium nitrate via irrigation.