Seed preconditioning modulates growth, ionic relations, and photosynthetic capacity in adult plants of hexaploid wheat under salt stress

In order to assess whether seed priming could improve salt tolerance in spring wheat (Triticum aestivum L.) a study was carried out by soaking the seeds of two cultivars, MH-97 (salt sensitive) and Inqlab-91 (salt tolerant), for 12 h in distilled water or 100 mol m(-3) of calcium chloride (CaCl2), potassium chloride (KCl), or sodium chloride (NaCl). The primed seeds (P-seeds) of each treatment and non-primed seeds (NP-seeds) were sown in a field in which NaCl salinity of 15 dS m(-1) was developed. Calcium chloride followed by KCl and NaCl was found to be effective in alleviating the adverse effect of salt stress on both cultivars of wheat in terms of biomass production, grain yield, and net CO2 assimilation rate. Although all priming agents were found to be effective in reducing the shoot Na+ levels in both cultivars, the effect of KCl was very pronounced, because it significantly reduced shoot Na+ in both cultivars under saline conditions. In conclusion, although all three priming agents CaCl2, KCl, and NaCl, were effective in alleviating the adverse effect of salt stress on wheat plants, their effects on altering the levels of different ions and photosynthetic rate were different in the two cultivars.