中文摘要：

通过为期60 d的田间模拟试验,以1年生落羽杉、美国山核桃和乌桕实生苗为试材,对3树种在涝渍胁迫下的适应性和生理调节机制进行了初步研究。结果表明：（1）3树种具有不同程度的耐涝能力。在淹水和渍水胁迫的前30 d,3树种叶片内的超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（ASA-POD）活性,以及抗坏血酸（ASA）、还原性谷胱甘肽（GSH）、脯氨酸（Pro）含量和可溶性蛋白（SP）含量皆呈显著上升趋势。（2）3树种耐涝能力存在显著差异,其中落羽杉的耐涝性最强,美国山核桃的次之,乌桕的最弱。在50 d的淹水胁迫期内,落羽杉叶片或根系中的SOD等6个指标的平均增量显著超过美国山核桃和乌桕,而且前者可保持连续增长并维持在较高水平,而美国山核桃和乌桕在水分胁迫30 d后呈现大幅下降趋势。（3）3树种的耐水机制可能与形态建成、酶促和非酶促抗氧化、渗透调节等适应性环节的启动有关。

英文摘要：

Based on field simulation experiment of one-year-old seedlings during 60 days,the preliminary research,aimed to understand the waterlogging or flooding tolerance and adaptation mechanisms of three different three species（i.e.Taxodium distichum,Carya illinoensis,Sapium sebiferum）,was conducted.The results were as follows：（1） In differn level,the three tree species all showed perfect ability tolerant to waterlogging or flooding.Under the first 30 days of waterlogging and flooding stress,superoxide dismutase（SOD） activity,ascorbic acid peroxidase（POD） activity,ascorbic acid（ASA） content,reducing glutathione（GSH） content,proline（Pro） content and soluble protein（SP） content in the leaves or roots of the three tree species,both showed significant rise.（2）However,there was a remarkable different in their waterlogging or flooding resistant ability among the three tree species.T.distichum had the strongest tolerance to waterlogging or flooding,C.illinoensis the middle,and S.sebiferum the most weakest.During the first 50 days of waterlogging or flooding stress,the average increment of SOD,ASA-POD,ASA,GSH activeness and Pro and SP content in the leave or roots of T.distichum were not only greatly higher than the ones in other two tree species,but also kept the continuing growth tendency and maintained at high levels,while those indexes in other two tree species showed a trend of sharp decline in 30 days of waterlogging or flooding.（3） For the 3 trees,water resistant mechanism was probably related to their regulation ability of seedling structure,antioxidant enzymes and antioxidant synthesis,etc.