This study was carried out in the Seed Research Laboratory of the Department of Crop Science, Ferdowsi University of Mashhad, Iran in summer 2011. Rice (cv. Khazar) seeds were soaked in 0, 20, 50 and 100 mg l-1 SA (salicylic acid) aerated solutions for 24 h and then dried back to original moisture content and were sown in three temperature (28° C as normal and 12°C and 8°C as chilling temperature conditions). At first step, both treated and untreated seeds were sown at optimum temperature (28°C). Then to apply chilling temperature, 15 days after sowing, one set of the seeds were exposed to12°C and 8°C under controlled conditions. Results showed that all seedlings raised from seeds primed with SA solutions produced a higher root and shoot length, final emergence percentage (FEP), relative water content (RWC) and also lower mean emergence time (MET) and time to 50 % emergence (E50) in comparison with untreated seeds. Antioxidant enzyme system efficiently responded to the stress conditions and the priming treatment. Also seedling raised from primed seeds showed higher antioxidant activity at each temperature compared with control.

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