Do primed seeds after drought stress have higher germination recovery efficiency compared to unprimed seeds?

From the ecological and economic point of view Agropyron elongatum, among perennial grasses, has a special place. This study was conducted to determine the most appropriate seed priming treatment and whether after a temporary stress removal, primed seeds have a higher recovery efficiency compared with unprimed seeds? In this research, seed was treated with different osmo and hydro priming and evaluated their effect by conducting germination test under drought stress (-1.2 and -1.4 MPa PEG) and recovery test. Hydro-primed seeds at 10 °C at all times (12, 24, 36 and 48 h) during priming; most indices of germination significantly improved compared to unprimed seeds. Also, seeds treated with osmopriming at both temperatures (10 & 15 °C) and all times of priming compared to unprimed seeds in the stress level of -1.2 MPa, the germination characteristics were improved. However, by increasing the potential of stress, few priming treatments have been able to maintain their superiority. It appears that priming can partially be effective on stress resistance and if the stress threshold is slightly higher than expected (this threshold for the Agropyron seeds in this study was -1.2 MPa) cannot have a noticeable effect on resistance to drought stress and can even be harmful too. All treatments which were placed in stressful situations and then moved to fresh water, showed a variety of recovery responses. As we viewed, primed seeds with a solution of -0.6 MPa urea for 12 h at 15 °C and followed by PEG solutions (-1.2 and -1.4 MPa) for 5 days and subsequently moved to fresh water conditions, had higher performance compared to unprimed seeds (P