采用盆栽法,对NaCl 胁迫条件下(2. 0、4. 0、6. 0、8. 0 mg·g^-1 NaCl)1 年生海滨木槿(Hibiscus hamabo Sieb. etZucc.)扦插苗叶片中电解质渗出率,叶绿素、丙二醛(MDA)、脯氨酸和可溶性糖含量以及SOD 和POD 活性等生理指标的动态变化进行了比较和分析。结果显示,在质量浓度较低(2. 0 和4. 0 mg·g-1 )的NaCl 胁迫条件下,海滨木槿叶片的叶绿素含量高于对照组,而在质量浓度较高(6. 0 和8. 0 mg·g^-1 )的NaCl 胁迫条件下叶绿素含量则有所降低;随NaCl 胁迫时间的延长,各处理组海滨木槿叶片的叶绿素a 与b 的比值呈先减小后增大的趋势,但变化幅度较小。在2. 0 和4. 0 mg·g-1 NaCl 胁迫条件下,整个实验期间(70 d)叶片的电解质渗出率与对照组间几乎没有显著差异(P>0. 05);而在6. 0 和8. 0 mg·g^-1 NaCl 胁迫条件下叶片的电解质渗出率均极显著高于对照组(P<0. 01)。各处理组叶片的MDA 含量随NaCl 胁迫时间的延长先升高后降低,甚至低于对照组,且在处理的第20 和第70 天与对照组差异不显著。各处理组叶片的脯氨酸含量随NaCl 胁迫时间的延长总体上呈先急剧升高后逐渐下降的趋势,但均高于对照组;各处理组叶片的可溶性糖含量随NaCl 质量浓度的提高以及胁迫时间的延长没有表现出一定的变化规律。随NaCl 胁迫时间的延长,各处理组叶片的SOD 活性呈先升高后降低的趋势,而POD 活性呈先降低后升高的趋势,但总体上均高于对照组。研究结果表明,海滨木槿对一定浓度的NaCl 胁迫具有一定的耐性,且对胁迫伤害具有一定的修复能力。

The dynamic changes of physiological indexes including electrolyte permeability, contents of chlorophyll, MDA, proline and soluble sugar, and activities of SOD and POD in leaf of one-year-old cutting seedling of Hibiscus hamabo Sieb. et Zucc. were compared and analyzed under NaCl stress condition (2. 0, 4. 0, 6. 0 and 8. 0 mg·g-1 NaCl) by pot-culture method. The results show that chlorophyll content in leaf of H. hamabo under NaCl stress condition with low concentrations (2. 0 and 4. 0 mg·g^-1) is higher than that in the control, but decreases with high concentrations (6. 0 and 8. 0mg·g^-1). With prolonging of NaCl stress time, ratio of Chla to Chlb in leaf in all treatment groups (2. 0-8. 0 mg·g^-1 NaCl ) appears the trend of first decreasing and then increasing, but change range of ratio of Chla to Chlb is smaller. Under 2. 0 and 4. 0 mg · g^-1 NaCl stress condition, electrolyte permeability in leaf almost has no significant difference (P >0. 05) compared with that in the control during whole experiment period (70 d), but under 6. 0 and 8. 0 mg·g-1 NaCl stress condition, that is very significantly higher than that in the control (P<0. 01). MDA content in leaf in all treatment groups appears the trend of first increasing and then decreasing and even lower than that in the control with prolonging of NaCl stress time, and has no significant difference compared with the control at thetwentieth day and the seventieth day of NaCl stress. Generally, proline content in leaf in all treatment groups appears the trend of first increasing sharply and then decreasing gradually with prolonging of NaCl stress time, but all higher than that in the control. Changes of soluble sugar content in leaf in every treatment group all don’t have a certain regularity with NaCl stress concentration rising and NaCl stress time prolonging. With prolonging of NaCl stress time, SOD activity in leaf in all  treatment groups appears the trend of first increasing and then decreasing, while POD activity appears the trend of first decreasing and then increasing, but generally those are higher than in the control. It is suggested that H. hamabo possesses some tolerance to NaCl stress in a certain range of concentration and a certain repairing ability to damage of NaCl stress.