The Role of Priming on Seed Reserve Utilization and Germination of Mountain Rye (Secale montanum) Seeds Under Salinity Stress

Low seed germination and seedling emergence is one of the main problems in saline areas. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stress. The objective of this research was to evaluate the effect of seed priming with gibberellin، NaCl and water on seed germination and seed reserve utilization and germination of Mountain Rye (Secale montanum) seeds under salinity stress in the Seed Laboratory of Department of Agronomy and Plant Breeding، the University of Tehran، Karaj، Iran. Treatments were combinations of 5 levels of salinity stress (0، -4، -8، -12 and -16 bar) and 4 levels of seed priming and control with 3 replications. Results indicated that with increase in salinity stress، germination components such as germination percentage، germination index، mean time to germination، seedling dry weight of utilized (mobilized) seed، seed reserve utilization efficiency and seed reserve depletion percentage decreased، but seed priming showed lower reduction. The highest germination percentage (85. 3%) was obtained by hydro-priming and halo-priming in control conditions. The highest germination index (42. 2) and the minimum mean germination time (1. 02) were obtained from hydro-priming in control conditions. But in higher levels of osmotic pressures، the highest germination percentage، germination index and the minimum means germination time were obtained from priming with gibberellin. In all of the drought levels، primed seeds possessed more germination rate and seedling dry weight than control. Across salinity osmotic pressures، halo-priming had a greater weight of utilized (mobilized) seed reserve. The highest seed reserve depletion percentage and seedling dry weight were achieved from halo-priming and minimum osmotic pressure. Also، seed priming increased antioxidant enzyme activity during seed germination process. It is concluded that priming results in improvement in germination components of Mountain Rye in salinity stress conditions and increases the resistance of Mountain Rye to salinity stress in germination phase.