Effect of gibberellic acid and kinetin on nitrogen content and nitrate reductase activity in wheat under saline conditions

Increasing levels (0 to 12 dSm⁻¹) of chloride and sulphate salinity decreased the leaf area, straw and grain yield of wheat (Triticum aestivum L.); the magnitude of decrease being less in tolerant cultivar WH-533 as compared to the sensitive C-306. Pre-sowing seed soaking treatments with gibberellic acid (0.4 mM), kinetin (0.4 mM) and gibberellic acid (0.4 mM) + kinetin (0.4 mM) alleviated the deleterious effects of chloride as well as sulphate salinity in both the cultivars. The combined treatment of gibberellic acid (0.4 mM) + kinetin (0.4 mM) was most effective. It was further observed that the plant growth regulator induced salinity stress alleviation was due to a concomitant increase in the tissue N content and nitrate reductase activity.