摘要:研究了等渗透势(-0.79、-1.83 MPa)盐分胁迫(NaCl)和水分胁迫(PEG)对西伯利亚白刺(Nitraria sibirica)幼苗生长及不同组织离子吸收分配的差异，探讨白刺抗旱和耐盐的相互关系。结果表明，与对照相比，-1.83 MPa NaCl和PEG处理后白刺幼苗的株高、茎粗、主根长和干物重均极显著(P＜0.01)降低，可溶性糖、脯氨酸和丙 二醛含量均显著(P＜0.05)或极显著(P＜0.01)升高，其中NaCl对幼苗生长的抑制作用显著(P＜0.05)大于PEG处理。不同器官离子含量，NaCl各处理的白刺幼苗Na⁺含量均上升，K⁺含量均先升后降，Ca²⁺、Mg²⁺含量及K⁺/Na⁺、Ca²⁺/Na⁺和Mg²⁺/Na⁺值均下降；PEG各处理的白刺幼苗Na⁺含量均先降后升，K⁺、Ca²⁺、Mg²⁺含量均下降，K⁺/Na⁺、Ca²⁺/Na⁺和Mg²⁺/Na⁺值均先升后降。不同器官离子的变化幅度以根中最大，茎次之，叶中最小。白刺幼苗主要是通过盐离子的区域化分布和调节幼苗体内的离子平衡来抵抗盐害的，通过积累大量有机小分子物质来抵抗旱害的。

关键词:盐分胁迫  水分胁迫  白刺  渗透调节  离子的吸收和分配

AbstractThe effects of iso-osmotic conditions (-0.79 MPa and -1.83 MPa) of salt stress (NaCl) and water stress (PEG) on seedling growth, and ionic absorption and distribution in different organs of Nitraria sibirica were studied, and the relationship between drought resistance and salt tolerance was analyzed. The results showed that, compared to the control, the plant height, stem diameter, taproot length and dry weight of seedlings decreased significantly (P＜0.05), while the contents of soluble sugar, proline and MDA increased significantly (P＜0.05) under the treatments of -1.83 MPa salt and PEG., in which the growth inhibition effect of salt treatment exceeded significantly (P＜0.05) that of PEG treatment. Under NaCl stress, the Na⁺ content in different organs of Nitraria sibirica seedlings showed an upward trend, the K⁺ content rose firstly and then went down, and the contents of Ca²⁺ and Mg²⁺ as well as the ratios of K⁺/Na⁺, Ca²⁺/Na⁺ and Mg²⁺/Na⁺ showed a downward trend. Under PEG stress, the Na⁺ content in different organs of Nitraria sibirica seedlings went down firstly and then rose, the contents of K⁺, Ca²⁺ and Mg²⁺ decreased, and the ratios of K⁺/Na⁺, Ca²⁺/Na⁺ and Mg²⁺/Na⁺ rose firstly and then went down. Among different organs, the change magnitude of ions was the largest in roots, followed by stems, and the smallest in leaves. Nitraria sibirica seedlings could resist salt stress by changing the distribution of salt ions and regulating their balance in the plants, and could resist drought stress by accumulating a large amount of small organic molecules.

Key wordssalt stress  water stress  Nitraria sibirica   osmotic adjustment  ionic absorption and distribution

文章编号： 0258_7106 (2016) 01_0018_15 中图分类号： P618.41 文献标志码：A

改回日期：2015_07_11

基金项目

**通讯作者耿新霞， 女， 1979年生， 助理研究员， 成矿规律研究方向。 Email： gen gxinxia@cags.ac.cn