Sand priming improves alfalfa germination under high-salt concentration stress

Seeds of two alfalfa (Medicago sativa L.) varieties, cv. Victoria and Golden Empress, were used to investigate the effects of sand priming on germination and physiological and biochemical changes under high-level salt concentration (0.8% NaCl) stress. Seeds were mixed with sand containing 4% (v/w) water, sealed in plastic box, and then were primed at 15 degrees C for 48 h. The results showed that germination percentage was significantly higher than that of the unprimed seeds after sand priming. The priming treatment significantly enhanced the activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and soluble sugar content and reduced the malondialdehyde (MDA) accumulation under the salt stress condition. The results suggested that sand priming was an effective method to enhance the ability of salt tolerance and to improve seed germination and seedling growth of alfalfa under high-salt concentration stress condition. This priming method seems to be possible to apply in alfalfa production in high saline soils in the future.