中文摘要：

为了解喜树对涝渍土壤条件的适应性，通过温室土培盆栽试验，从形态和生理两方面探讨了涝渍胁迫对1年生喜树（Camptotheca acuminata）实生苗的影响，试验分对照、轻度渍水、渍水和淹水等4个处理，处理时间为21d。结果表明，喜树根系生长以轻度渍水最好，其次为对照，而渍水和淹水的处理初生根系逐渐腐烂、死亡，与之相对应。轻度渍水处理的根系活力与对照无显著差异，但渍水和淹水处理随着处理时间的延长逐渐下降，同时观察到渍水和淹水的喜树茎在水面以下部位出现较多的皮孔。随着处理时间的延长，轻度渍水处理喜树叶片内POD和SOD活性一直保持较高水平，渍水和淹水处理则表现出先升高后下降的趋势，各个处理叶片中O2、H2O2和MDA含量有逐渐升高的趋势，且各处理之间均表现为淹水〉渍水〉轻度淹水〉对照。各处理根系LDH活性在处理前期较对照低，而在处理的中后期，LDH活性均比对照高，以渍水和淹水处理最高。因此，喜树在轻度渍水条件下，一方面由于皮孔和不定根的增多，根系能够获得更多的氧气，另一方面由于POD和SOD抗氧化酶活性的增强，降低了O2和H2O2对细胞的伤害，喜树能够在轻度渍水的立地上正常生长。关键词喜树涝渍胁迫形态生理

英文摘要：

Aims Camptotheca acuminate is a common tree species in southern and eastern China. It is planted widely as a virescence species and is cultivated as an officinal species, because its seed, leaf and stem can be used to distill camptothecin, which is used to treat cancer. Our objective was to examine C. acuminate＇s resistance to wateflogging. Methods One-year seedlings of C. acuminata were grown in pots in a greenhouse in January, and we implemented four treatments in May： CK （common soil water content）, A （water level 10 cm under soil surface）, B （water level equal with soil surface） and C （water level 4 cm above soil surface）. Treatments lasted 21 days, and indexes of lenticels, root growth, root vigor, POD, SOD, MDA and LDH were determined at different times after treatment. Important findings Root growth was better in A and CK treatments, and roots gradually died in B and C treatments. Comparatively, root vigor was higher in A and decreased gradually under B and C with treatment time. Many lenticels were observed on the stem under B and C, but not under CK and A. The POD and SOD activity of leaves of A treatment were higher during treatment, but increased and then decreased under B and C treatments. The production rate of O2, H2O2 content and MDA content of leaves of A, B and C treatments increased gradually with treatment time, but was higher under C and B treatments. The LDH activity of roots in A, B and C treatments was lower early in treatment, but increased significantly late in treatment. We conclude that C. acuminata grows well in lightly waterlogged sites, but not in waterlogged and flooded sites.