The effect of seed priming on germination parameters of annual medic (Medicago scutellata L.) seed under chilling stress conditions

The chilling stress during seed germination of most plants cause disorder in many phisiological processes, prevention of radicle exit and decrease germination percentage. So, the effect of different seed priming treatments on seed germination parameters changes of annual medic plant under chilling stress was evaluated as a factorial experiment in completely randomized design with four replications. Treatments were consisted of different primings (hydropriming, halopriming, osmopriming and no priming) and five levels of temperature (3, 6, 9, 12 and 15 ˚C). Results showed that reduction of temperature caused linearly reduction of germination rate in seeds treated with hydroprime and osmoprime, but halopriming treatment was improvement germination percentage under chilling stress. The maximum radicle weight was observed in hydropriming treatment. Reducing of temperature increased amount of proline in all priming treatments. Moreover, osmopriming treatment caused increase activity of catalase and guaiacol peroxidase enzymes at temperature of 3˚C. In conclusion, hydropriming treatment is suitable for germination rate and percentage improvement and better establishment of annual medic plant under chilling stress conditions that this can appropriate for increase the exposure potential of this plant as green manure in cold and mild regions of the country.