EFFECTS OF WATER SALINITY ON GROWTH INDICES AND PHYSIOLOGICAL PARAMETERS IN SOME PISTACHIO ROOTSTOCKS

Abstract

Pistachio is one of the most important horticultural crops in Iran. The majority of the pistachio producing regions is located in arid and semi-arid areas with saline conditions. Therefore, selection of suitable rootstocks is important for increasing yield efficiency of this important nut crop. In this study, the effect of four water salinity levels (0.75, 5, 10 and 15 ds m−1) on growth indices and physiological parameters of four Pistacia vera L. rootstocks (Badami-e-Zarand A, Badami-e-Zarand B, Qazvini, and Sarakhs) were investigated under greenhouse conditions. After treatment for three months, leaf dry weight was reduced by about 30-50% at an irrigation water electrical conductivity (ECw) of 10 ds m−1. Badami-e-Zarand B was the most vigorous rootstock at the highest EC. Decreases in root and stem dry weight (average of all rootstocks combined) occurred at water salinity of 10 ds m−1. Chemical analysis of shoot and root indicated that the salinity affected the concentration and distribution of sodium (Na+), potassium (K+), and calcium (Ca2+) in pistachio rootstocks. The concentrations of Na+ and K+ increased with a rise in water salinity levels. Comparison between Na+ concentration of shoot and root showed that all examined rootstocks limited the Na+ transportation to shoot tissue up-to 15 ds m-1, and retained it in the roots. However, this ability was less in the Sarakhs rootstock. Based on measured parameters, Badami-e-Zarand B and Sarakhs could be considered as tolerant and sensitive pistachio rootstocks to water salinity, respectively.