Effect of Hormonal Priming and Osmopriming on Germination of Winter Savory (Satureja montana L.) Natural Population under Drought Stress

Abstract

Winter savory (Satureja montana L.) is an important medicinal, aromatic, and honey plant. In Croatia, it is widely distributed along the Adriatic coast, where it is frequently exposed to droughts. First, the winter savory natural population with the highest germination across different drought treatments after hydropriming was selected. Nine hundred seeds from each of the three natural populations (P1, P2, and P3) were hydroprimed (dH2O) for 48 h. The seeds were then germinated in drought treatments with different concentrations of polyethylene glycol (PEG 6000) (−0, −0.2, −0.4, −0.8, −1.2, −1.6, −2, −2.5, −3.0 MPa). Since P1 showed the best results in germination parameters, it was used for the second phase of the experiment, where the effect of hormonal priming (100 and 400 ppm GA3, 48 h in the dark) and osmopriming (0.2% and 0.6% w/v KNO3, 72 h in the dark) on seed germination and seedling morphological parameters of the selected winter savory population under drought stress conditions (−0.8 and −2.5 MPa) was evaluated. Although winter savory grows in dry areas, this study showed that extremely dry conditions (−3.0 and −2.5 MPa) negatively affected seed germination, but this effect can be mitigated by priming treatments, especially with the hormonal priming (GA3 400 ppm).