Abstract: Deterioration of internal physiological functions often occurs in seeds during natural storage. As the main site of reactive oxide species (ROS) production,mitochondria are the first destroyed organelles during the process of seed aging. To investigate the effect of physiological function in embryonic mitochondria of Siberian wildrye (Elymus sibiricus L.) seeds during the different storage duration,seed samples were evaluated after stored at room temperature for 0～4 years. The results showed that the germination potential,germination percentage and seedling fresh weight gradually decreased,and the number of dead seeds increased with the prolongation of storage duration. The activities of embryonic mitochondria malate dehydrogenase (MDH),glutathione reductase (GR),monodehydroascorbate reductase (MDHAR) gradually decreased,but the activity of superoxide dismutase (SOD) in dead seeds increased significantly. In addition,the production rate of mitochondrial O₂^·- increased,while mitochondrial H₂O₂ content showed a gradually decreasing trend. It indicated that mitochondrial O₂^·- accumulation was closely related to the cell oxidative damage.

Key words: Elymus sibiricus, Storage, Embryonic mitochondria, Antioxidative function

摘要： 种子在自然贮藏过程中常常伴随着内部生理机能的恶化，线粒体作为种子内活性氧（reactive oxide species，ROS）产生的主要位点是最先遭到破坏的细胞器。为探讨不同贮藏年限对老芒麦种胚线粒体抗氧化功能的影响，本试验以室温贮藏0～4年的老芒麦种子为材料，分析比较其老化规律及种胚线粒体抗氧化特性的变化规律。结果表明：随着贮藏年限的延长，老芒麦种子发芽势、发芽率和种苗鲜重逐渐下降，死种子逐渐增多，种胚线粒体苹果酸脱氢酶（mitochondria malate dehydrogenase，MDH）、谷胱甘肽还原酶（glutathione reductase，GR）、单脱氢抗坏血酸还原酶（monodehydroascorbate reductase，MDHAR）活性逐渐下降，但在死种子中超氧化物歧化酶（superoxide dismutase，SOD）活性显著升高。此外，在贮藏过程中老芒麦种胚线粒体O₂^·-产生速率不断上升，而H₂O₂含量则呈现逐渐降低的趋势，表明线粒体中O₂^·-的积累与细胞氧化损伤密切相关。

关键词: 老芒麦, 贮藏, 种胚线粒体, 抗氧化功能