The combined effect of gibberellic acid and long time osmopriming on seed germination and subsequent seedling growth of <i>Klussia odoratissima</i> Mozaff.

Abstract

Kelussia odoratissima Mozaff. is one of the endogenous plant species of Iran which is exposed to extinction during the recent decades. Seeds of this plant have dormancy that causes reduction of seed germination. Experiment was performed as factorial with complete randomized design with 3 factors: polyethylene glycol (PEG) priming, gibberellic acid (GA₃) treatment, GA₃ application time. This research was performed to evaluate priming effect alone and in combination with GA₃, on seed germination and seedling growth parameters. Results show that seed priming with PEG alone had negative effect and GA₃ application solely did not have any significant effect on the seed germination percentage in comparison with the control. Seedling growth responses to PEG priming was similar (in -1 MPa) or lesser (in -1.5 MPa) than control, GA₃ significantly improved seedling growth as compared to the control. Application of GA₃ after PEG was better than using of GA₃ before PEG or co-application of GA₃ and PEG. These results suggest that probably, GA₃ compensated negative effect on long time priming.

Key words: Gibberellic acid (GA₃), germination percentage, Kelussia odoratissima Mozaff., priming, seedling growth.