Abstract: Study the effects of temperature on the antioxidant physiology of seed imbibition has a positive significance in revealing the seed imbibition and germination mechanism. The experiment used Siberian wildrye (Elymus sibiricus) seeds as materials to explore the changes in seed germination characteristics and antioxidant indexes during the imbibition process under different temperature conditions (10℃,25℃ and 30℃). The results showed that compared to 25℃,the seed germination percentage,germination index and root length of Siberian wildrye seedlings under 10℃ and 30℃ stress were decreased significantly (P <0.05). 10℃ had a greater impact on seeds. The activities of peroxidase (POD),monodehydroascorbate reductase (MDHAR),glutathione reductase (GR) and the content of mitochondrial oxidized glutathione (GSSG) in Siberian wildrye seeds were decreased at 10℃,while the germination was inhibited and the germination time was delayed. The activities of catalase (CAT),POD,GR and the contents of mitochondrial ascorbic acid (AsA),glutathione (GSH) and GSSG were increased at 30℃treatment,which maintained the normal process of seed germination. The results of our experiment provide a basis for further understanding the changes of antioxidant physiology during seed imbibition,and have reference value.

Key words: Siberian wildrye, Temperature, Seed imbibition, Mitochondria, Antioxidant system

摘要： 研究温度影响种子吸胀过程中抗氧化生理的变化规律，对于揭示种子的萌发机制具有积极意义。本研究以老芒麦(Elymus sibiricus)种子为材料，探索在不同温度(10℃，25℃和30℃)下种子萌发特性和吸胀过程中抗氧化生理变化。结果表明，与25℃相比，在10℃和30℃胁迫下，老芒麦种子的萌发率、发芽指数以及幼苗根长均显著降低(P<0.05)。10℃对种子的影响更大，种子中过氧化物酶(Peroxidase，POD)、谷胱甘肽还原酶(Glutathione reductase，GR)、单脱氢抗坏血酸还原酶(Monodehydroascorbate reductase，MDHAR)活性和线粒体氧化型谷胱甘肽(Oxidized glutathione，GSSG)含量下降，发芽被抑制，萌发时间延迟。而30℃下种子中过氧化氢酶(Catalase，CAT)、POD，GR的活性和线粒体抗坏血酸(Ascorbic acid，AsA)、谷胱甘肽(Glutathione，GSH)、GSSG含量升高，继而保证了种子的正常萌发进程。试验结果为掌握种子吸胀过程中抗氧化生理的变化规律提供参考依据。

关键词: 老芒麦, 温度, 种子吸胀, 线粒体, 抗氧化系统