IMPACT OF SALT STRESS ON CONCENTRATIONS OF Na+ , Cl- AND ORGANIC SOLUTES CONCENTRATION IN PEA CULTIVARS

Abstract

To study the salt tolerance potential in pea cultivars (Pisum sativum L.), an experiment was conducted with nine local pea cultivars: Samarina Zard (SZ), Olympia (OL), Early Green (EG), Climax (CL), 2001-20 (2001), Meteor (M), Euro (E), 9200-1 (9200) and 9800-5 (9800). The plants were exposed to two NaCl treatments: 0 and 75 mM NaCl. At the end of the experiment, growth parameters, Cl- and Na+ in leaves and roots, and proline, quaternarium ammonium compounds, total free amino acids and total soluble sugars in leaves were measured. Saline treatment reduced the total biomass in all the pea cultivars. Thus, salt tolerance, based on growth reduction relative to the control treatment, was similar in all nine pea cultivars. However, regardless of the salt treatments, the cultivars EG, SZ, 9200, 9800 and CL were more vigorous among the nine cultivars. The cultivar 2001 had the highest leaf Na+ and Cl- concentrations these were the lowest in 9200. In the nine cultivars studied, an increase was noted in the leaf proline, free amino acids, QAC compounds and total soluble sugars with increase in the root zone salinity. Leaf proline and amino acids concentrations were negatively correlated with the leaf Na+ concentration suggesting that the synthesis of this organic solute is linked with the osmotic process adjustment rather than Cl- and Na+ toxicity.