Effect of sodium chloride on the growth and gas exchange of young<i>Ziziphus</i>seedling rootstocks

Abstract

SummaryAn experiment was conducted to study the effect of saline water (EC 0, 5, 10, 15 and 20 as NaCl) on growth, gas exchange and ion uptake in Ziziphus rotundifolia and Z. nummularia seedlings. No plants of Z. nummularia survived EC > 15 dS m–1. Shoot dry weight, leaf area and relative water content decreased significantly with variable magnitude in both species with increasing salinity. Reduction in gas exchange and stomatal conductance on account of salinity was higher in Z. nummularia. Salinity decreased the soluble sugars content whereas proline content increased. Absorption of sodium did not vary in roots of either species but Z. rotundifolia restricted the translocation of sodium to the shoot at the cost of potassium which is reflected in the Na/K ratio of roots and shoots. Present investigation suggest that rootstocks of Z. rotundifolia are comparatively salt tolerant due to a high rate of CO2 accumulation, osmotic adjustment, chlorophyll retention and restricted translocation of sodium from root to shoot. However, the results need to be tested under field conditions.