Original Article Effects of Osmo-Hydropriming and Drought Stress on Seed Germination and Seedling Growth of Rye (Secale Montanum

Germination and seedling establishment are the major and critical steps in establishment of the crops in the arid and semi-arid environments. In this study an experiment was conducted to evaluate the effects of different time seed priming (osmo-hydropriming) on germination and seedling growth of Secale montanume seeds under drought conditions. Seeds were immersed in water with osmotic potentials of-0.5,-1 and-1.5 MPa. PEG600 was employed to induce the required levels of osmotic potentials. Induction of hydropriming was obtained by immersing the seeds in distilled water with aeration and no aeration conditions. Both two priming treatments were conducted at 3 time duration (6, 12 and 24 hours). These primed seeds were germinated and grew at osmotic potentials of 0 (distilled water),-0.5,-1, and-1.5 MPa by PEG6000. Results showed that the seed germination and seed growth were inhibited by increasing drought stress as the germination percentage of hydroprimed seeds with aeration was reduced from 74.02 % to 60.45%. Both shoot and root growths were inhibited by increasing osmotic potential. Hydroprimed seeds with aeration caused reduction shoot and root length, while root/shoot length ratio was increased by hydroprimng without aeration. The least priming time (6 hr) had more effects on germination percentage. Result also showed that seed treatment at difference levels of PEG significantly affected germination characteristics. The highest germination percentage was obtained from seed priming with PEG induced-0.5 MPa osmotic potential. The highest root/shoot length ratio was related to osmopriming with-0.5 MPa. The time of osmopriming didn’t show significant effect on germination characters and seedling growth. However 6 h osmopriming was more effective