人工老化处理对芝麻种子生理生化特性的影响

以郑芝4号黑芝麻种子为材料，研究了人工加速老化处理对种子发芽指标﹑丙二醛(MDA)含量﹑过氧化物酶(POD)活性和超氧化物歧化酶(SOD)活性的影响。试验结果表明：随着种子老化加深，发芽势、发芽率、发芽指数﹑活力指数逐渐降低, 丙二醛含量逐渐升高。另外,老化种子内POD活性和SOD活性变化的总趋势是随老化时间延长而降低。由此认为芝麻种子人工老化及劣变的主要机制与抗氧化酶活性降低与和膜脂过氧化作用加剧有关。人工老化种子生活力出现快速下降的发芽势拐点是80%，其下降的趋势又与POD活性下降非常一致，POD可作为一个检测指标显示种子活力高低及丧失的特征。

Effects of artificial aging on physiological and biochemical characteristics of sesame seed

The germination index,malondialdehyde(MDA) content,and the activity of peroxidase(POD) and superoxide dismutase(SOD) were studied with black sesame(zhengzhi.4)seeds treated with high artificial aging.The results showed that germination potential,germination rate,germination index and vigor index were reduced gradually and the MDA content was raised with the aging seeds.The activity of POD and SOD decreased in aged seeds with extended treating time.The main mechanism for deterioration of sesame seeds during artificial aging was closely related to an increase of lipid peroxidation and a decrease in activity of antioxidant enzymes.The threshold for sesame seed viability was 80% artificial aging sesame seed germination potential whose decreasing tendency was consistent with POD activity,so POD activity may be an index to indicate the characteristic of height and loses of vigor in the seeds.