中文摘要：

研究不同程度土壤干旱胁迫及胁迫解除后侧柏叶片中抗氧化酶活性的动态变化,对侧柏的抗旱性及旱后复水的补偿效应机理进行初步探讨。以1年生的侧柏苗木为材料,采用盆栽试验,以土壤相对含水率（SRW）100.00%的处理为对照,测定不同水分胁迫强度（土壤相对含水率87.84%,70.00%,52.16%,40.00%）不同胁迫历时（胁迫历时0、30、45、60d）以及复水2、24、48h和72h侧柏叶片中超氧化物歧化酶（SOD）、过氧化物酶（POD）活性的变化。结果表明,侧柏叶片中SOD和POD活性均高于对照,且随着干旱胁迫强度的增大呈上升趋势。相同的干旱胁迫强度下,侧柏叶片中SOD活性随着胁迫历时的延长呈先上升后下降的趋势,而POD活性则一直呈上升趋势。不同水分胁迫历时下各处理在复水后2h,侧柏叶片中POD和SOD活性都急剧上升,且复水后较长一段时间内还保持较高的活性。较短时间的胁迫历时下,SOD和POD活性大体都呈上升-下降-略高于对照的趋势。适度水分胁迫使侧柏幼苗的抗氧化能力得到加强,长时间的水分胁迫会对侧柏抗氧化能力造成伤害。

英文摘要：

Dynamic changes of antioxidant enzymes during different water stress levels and after rewatering in P.orientalis leaves were studied to investigate the drought resistance and compensation effect mechanism after drought.One-year-old P.orientalis seedlings were selected as test materials.A potted experiment was conducted with 5 different soil relative water（SRW）levels,i.e.,100.00%,87.84%,70.00%,52.16%,and 40.00%,lasted for 15,30,45 dand 60d.The activities of superoxide dismutase（SOD）and peroxidase（POD）in the leaves were measured 2,24,48,72h after rewatering.With the aggravation of soil water stress,both activities of SOD and POD in the leaves were higher than the control.Under the same soil water stress level,SOD activity increased at the beginning and then went down as water stress lasting.The POD activity however,increased all the time.For different soil water stress levels and different drought durations,the activities of SOD and POD increased steeply 2h after rewatering,and also maintain a high activity for a long period after rewatering.After short drought stress,the activities of SOD and POD presented the trends of rising-dropping-higher than the control.The antioxidation ability could be strengthened by properly water stress but it could be damaged by severe drought stress.