Three seed priming techniques: hydropriming, halopriming and osmopriming, were compared for their effects on germination and vigour of pansy (Viola × wittrockiana Gams.) seeds at 20°C, 30°C and 35°C. Seeds were hydroprimed in the restricted volumes of water (600 and 700 µl H₂O·g seed^-1, 2, 3 or 4 days), haloprimed in KNO₃ solution (-1.5 MPa, 5 days), and osmoprimed in polyethylene glycol solutions (-1.0, -1.25 or -1.5 MPa PEG 8000, 7 days) at 15°C or 20°C. Seed germination and vigour tests were performed for untreated and primed seeds. Generally, hydropriming negatively affected the speed of germination, the percentage of germinating seeds and germination capacity. Halopriming accelerated seed germination at 20°C, 30°C and 35°C but did not influence the percentage of germinating seeds and germination capacity. Osmopriming of seeds in PEG solution of osmotic potential –1.0 MPa at 20°C not only improved germination rates at 20°C, 30°C, and 35°C to the highest extent, but also increased percentage of germinating seeds at 30°C and 35°C most effectively and positively affected seed germination capacity at 20°C and 30°C.

15-29