模拟滨海盐渍土离子组分，研究了不同浓度（3、5和8 g·kg^-1）混合盐胁迫条件下3个乔木树种台湾含笑〔Michelia compressa （Maxim.） Sarg.〕、‘中山杉406’（Taxodium hybrid ‘Zhongshanshan 406’）和女贞（Ligustrum lucidum Ait.）叶片相对电导率、丙二醛（MDA）含量、抗氧化酶活性以及不同器官中Na+和K+的吸收与分布。结果表明：除8 g·kg^-1混合盐处理组的女贞外，各处理组3个乔木树种全部存活。3个乔木树种叶片的相对电导率和MDA含量均随着混合盐浓度的提高而增大。各处理组3个乔木树种叶片的相对电导率从高到低依次为台湾含笑、女贞、‘中山杉406’，MDA含量则基本上与之相反。随着混合盐浓度的提高，台湾含笑叶片中过氧化物酶（POD）活性显著升高，5和8 g·kg^-1混合盐处理组的过氧化氢酶（CAT）活性显著高于3 g·kg^-1混合盐处理组及对照组（0 g·kg^-1混合盐），不同处理组间超氧化物歧化酶（SOD）活性差异不显著。8 g·kg^-1混合盐处理组‘中山杉406’叶片中SOD和CAT活性显著高于3和5 g·kg^-1混合盐处理组及对照组；3、5和8 g·kg^-1混合盐处理组间的POD活性则差异不显著，但显著高于对照组。混合盐胁迫下女贞叶片中SOD、POD和CAT活性均无显著变化。随着混合盐浓度的提高，3个乔木树种根、茎和叶片中Na+含量总体上呈升高的趋势，3个乔木树种不同器官中K+含量的变化趋势各异，K+／Na+比则总体上呈下降的趋势。各处理组‘中山杉406’根、茎和叶片的K+／Na+比总体上高于台湾含笑和女贞。综合而言，供试3个乔木树种中‘中山杉406’的耐盐性最强，是沿海地区盐碱地改良以及造林绿化的优选树种。

By simulating ion components of coastal saline soil， relative electric conductivity， malondialdehyde （MDA） content， and antioxidant enzyme activities in leaves， and absorption and distribution of Na+ and K+ in different organs of three arbor species of Michelia compressa （Maxim.） Sarg.， Taxodium hybrid ‘Zhongshanshan 406’， and Ligustrum lucidum Ait. under different concentrations （3， 5， and 8 g·kg^-1） of mixed salt stresses were investigated. The results show that three arbor species in each treatment group all survive except for L. lucidum treated with 8 g·kg^-1 of mixed salt stress. Both relative electric conductivity and MDA content in leaves of three arbor species increase with enhancing of mixed salt stress concentration. Relative electric conductivity in leaves of three arbor species in each treatment group from high to low is M. compressa， L. lucidum， T. hybrid ‘Zhongshanshan 406’， while their MDA content is on the contrary basically. With enhancing of mixed salt concentration， peroxidase （POD） activity in leaves of M. compressa increases significantly， and its catalase （CAT） activity in 5 and 8 g·kg^-1 mixed salt stress treatment groups are significantly higher than that in 3 g·kg^-1 mixed salt stress treatment group and the control group （0 g·kg^-1 mixed salt）， while there is no significant difference in superoxide dismutase （SOD） activity among different treatment groups. SOD and CAT activities in leaves of T. hybrid ‘Zhongshanshan 406’ in 8 g·kg^-1 mixed salt stress treatment group are significantly higher than those in 3 and 5 g·kg^-1 mixed salt stress treatment groups and the control group； while there is no significant difference in POD activity among 3， 5， and 8 g·kg^-1 mixed salt stress treatment groups， but their POD activity is higher than that in the control group. There is no significant change in SOD， POD， and CAT activities in leaves of L. lucidum under mixed salt stress. With enhancing of mixed salt stress concentration， Na+ content in roots， stems， and leaves of three arbor species shows an upward trend in general， K+ content in different organs of three arbor species shows different changing trends， and K+／Na+ ratio shows a downward trend in general. K+／Na+ ratio in roots， stems， and leaves of T. hybrid ‘Zhongshanshan 406’ in each treatment group is generally higher than that in M. compressa and L. lucidum. In general， T. hybrid ‘Zhongshanshan 406’ has the best salt tolerance among three arbor species tested， indicating that it is the optimal tree species for saline land improvement， and afforestation and greening in coastal areas.