The objectives of this study were to evaluate the role of hydro and osmopriming on improvement of germination parameters of Tall Wheatgrass (Agropyron elongatum) under simulated drought stress by PEG. Germination was delayed by drought stress in primed and nonprimed seeds. With increasing the osmotic potential, all of the investigated traits began to decrease. Seeds were able to germinate at 0, −0.4 and −0.8 MPa concentrations of PEG but dearth seed germination was observed at −1.2 MPa. Osmopriming increased germination parameters under drought stress rather than hydropriming treatment. Finally, Tall Wheatgrass did have positive reaction in both priming treatments on germination parameters especially at lowest osmotic potentials (-1.2 MPa).
