采用盆栽试验方法,对 0(CK)、2、4、6、8 和 10 g· kg^-1 NaCl 胁迫条件下木槿( Hibiscus syriacus L.)和海滨木槿(H. hamabo Sieb. et Zucc.)扦插苗及木槿嫁接苗(以海滨木槿为砧木)叶片的叶绿素、脯氨酸和可溶性糖含量,超氧化物歧化酶(SOD)活性,相对电导率和丙二醛(MDA)含量以及根、茎、叶中的 K⁺和 Na⁺含量,K⁺ / Na⁺值等生理指标的差异进行了比较分析。 结果表明:在不同质量浓度 NaCl 胁迫条件下,木槿嫁接苗、木槿和海滨木槿扦插苗的各项生理指标均有明显差异。 各处理组木槿嫁接苗叶片的叶绿素、脯氨酸和可溶性糖含量不但高于对照也均高于木槿和海滨木槿扦插苗;总体上,尽管各处理组 3 种苗木的叶片相对电导率和 MDA 含量均高于对照,但木槿扦插苗的叶片相对电导率最高、MDA 含量最低;随 NaCl 质量浓度的提高,各处理组 3 种苗木叶片的 SOD 活性均呈现波动的变化趋势,且波动幅度较小。 在 NaCl 胁迫条件下,3 种苗木根、茎和叶中的 K⁺含量呈现波动的变化趋势,其中叶中的 K⁺含量均最高;随 NaCl 胁迫浓度的提高,3 种苗木不同器官的 Na⁺含量均不同程度提高且均显著高于对照,而K⁺ / Na⁺值均呈下降趋势;总体上看,不同处理组海滨木槿扦插苗根和木槿嫁接苗地上部分的 K⁺ / Na⁺值均最大。 另外,在 10 g· kg^-1 NaCl 胁迫条件下木槿扦插苗植株均未成活。 研究结果显示:以海滨木槿为砧木能提高木槿的耐盐性,使木槿嫁接苗的多项生理指标优于其扦插苗。

Difference of physiological indexes including contents of chlorophyll, proline and soluble sugar, SOD activity, relative conductivity and MDA content in leaf and contents of K⁺ and Na⁺, K⁺ / Na⁺ value in root, stem and leaf of cutting seedlings of Hibiscus syriacus L. and H. hamabo Sieb. et Zucc.  and grafted seedling of H. syriacus (taken H. hamabo as rootstock) under 0 (CK), 2, 4, 6, 8 and 10 g· kg^-1 NaCl stress were comparatively analyzed by pot experiment method. The results show that there are obvious differences in every physiological index among grafted seedling of H. syriacus and cutting seedlings of H. syriacus and H. hamabo under NaCl stress with different concentrations. Not only contents of chlorophyll, proline and soluble sugar in leaf of grafted seedling of H. syriacus in all treatment groups are higher than those of the control, but also are higher than those of cutting seedlings of H. syriacus and H. hamabo. Generally, in spite of relative conductivity and MDA content in leaf of three plant seedlings in all treatment groups all are higher than those of the control, relative conductivity in leaf of cutting seedlings of H. syriacus is the highest and its MDA content is the lowest. With rising of NaCl concentration, SOD activity in leaf of three plant seedlings in all treatment groups appears a fluctuant trend but the fluctuant range is small. Under NaCl stress, K⁺ content in root, stem and leaf of three plant seedlings appears a fluctuant trend, in which that is the highest in leaf. With rising of NaCl concentration, Na⁺ content in different organs of three plant seedlings all increase at different degrees and all are higher than that of the control, but K⁺ / Na⁺ value all appears a downward trend. Generally, in different treatment groups, K⁺ / Na⁺ values in root of cutting seedling of H. hamabo and in above-ground part of grafted seedling of H. syriacus are the biggest. In addition, cutting seedlings of H. syriacus all are not survival under 10 g· kg^-1 NaCl stress. It is suggested that taking H. hamabo as rootstock is able to improve salt tolerance of H. syriacus and to lead to physiological indexes of grafted seedling of H. syriacus better than those of its cutting seedling.