古侧柏种子活力与树龄的关系研究

Relationship Between Vigour of Seeds and Age of Old Platycladus orientalis

以陕西黄帝陵、河南嵩阳书院、山东岱庙、山西晋祠、北京中山公园、北京卧佛寺不同树龄侧柏(20～3 000年)种子为试材,测定其千粒重、发芽指数、活性氧(ROS)、丙二醛(MDA)、ROS清除酶(SOD、POD、CAT、GR、APX)活性,分析各指标与树龄的变化关系,探讨通过古侧柏种子活力判断古树衰老程度的可能性。结果表明:所选6个地点侧柏种子千粒重和树龄无相关关系;6个地点20年侧柏种子的发芽率和各ROS清除酶活性均高于其他树龄侧柏种子,古侧柏种子ROS和MDA含量并没有随树龄增加而增大;6个地点侧柏种子发芽指数、ROS(O2.-、H2O2、.OH)、MDA、各ROS清除酶活性与树龄无显著相关关系;3 000年古侧柏与20年侧柏相比,种子发芽指数和ROS清除酶活性仍较高,而ROS和MDA含量相对较低。可见,高龄古侧柏的种子生理机能没有明显衰退迹象。

To understand the relationships in seed germination and judge the aging of Platycladus oriental- is ,we determined and analyzed the dynamic changes of 1 000-grain weight,germination index, reactive oxy- gen species （ROS） and malonyldialdehyde （MDA） contents,activities of anti-oxidation enzymes by using the seeds of different ages of P. orientalis collected from Yellow Emperor mausoleum,Songyang Academy, Dai Temple,Jinci Temple,Zhongshan Park and Sleeping Buddha Temple. The results showed that 1 000- grain weight had no significant correlation with the ages of P. orientalis collected from six regions. Germi- nation index and the active of anti-oxidative enzyme of 20-year-old P. orientalis were higher than that of old P. orientalis. However,the content of ROS did not go up with tree age of old P. orientalis. Above all,the seeds of old P. orientalis which taken from different ages and locations had no significant correlation be- tween germination index,ROS （O2 , H202, · OH）,MDA contents and activities of anti-oxidation enzymes （SOD,POD,CAT,GR,APX）. Compared to the seeds of 20-year-old and 3000-years-old P. orientalis,there were higher germination index and activities of anti-oxidation enzymes and lower contents of ROS and MDA contents. The research discovered that seed vitality of 20-year-old P. orientalis was relatively strong,but there were no clear decline in physiological functions of old P. orientalis seeds in different locations.