NaCl胁迫下沙枣幼苗的离子代谢特性

Study on Ion Metabolism Characteristics of Elaeagnus angustifolia Seedlings under NaC l Stress

沙枣（Elaeagnus angustifolia L.）是胡颓子科（Elaeagnaceae）胡颓子属（Elaeagnus Lnn.）的落叶小乔木,主要分布于我国西北五省,在新疆塔里木河、玛纳斯河、甘肃疏勒河、内蒙古的额济纳河两岸有天然的沙枣林分布,在北京、天津和山东等地也开展了引种栽培[1-2]。沙枣的果实、叶片、花和种子等在食品加工、药物提炼和饲用开发等领域具有较高的价值,沙枣木材也是高级家具和工艺品制作的良材[1];同时,沙枣具有耐旱、耐盐碱和抗风沙的特性,并且沙枣根系上有固氮根瘤菌,能提高土壤肥力,改善土壤环境,因此,

[Objective]To further understand the ion metabolism characteristics of Elaeagnus angustifolia L. under Na Cl stress. [Method]The seedlings of two E. angustifolia L. provenances,which were Alaer（ salt tolerance provenance） and Yinchuan（ salt sensitive provenance）,were treated by three Na Cl concentrations（ 0,150,300 mmol·L- 1） and sampled at the 7th day and the 30 th day to measure the Na＋,K＋,Ca2 ＋,and Mg2 ＋contents,K＋/ Na＋ratio and selective absorption and transportation of K＋in tissues（ roots,stems and leaves）. [Result]The results showed that the Na＋content in the organizations of E. angustifolia L. sharply increased with the increase of Na Cl concentration. With prolonging of stress time,the Na＋content increased in roots,and decreased in stems and leaves. After seedlings of the two provenances were treated with 150 mmol·L- 1Na Cl for 7 days,the Na＋content was2. 10 times and 2. 23 times in leaves,respectively,compared with the control groups,and was 1. 79 times and 1. 57 times in root. Meanwhile,the difference between two provenances showed a expanding trend with the increase of Na Cl concentration and stress time. With the increase of Na Cl concentration and extension of stress time,the K＋content,Ca2 ＋content and K＋/ Na＋ratio in organizations decreased gradually. Meanwhile,the Alaer provenance seedlings accumulated more Na＋in roots and less Na＋in leaves than that of Yinchuan provenance,and the K＋content,Ca2 ＋content and K＋/ Na＋ratio decreased less in the Alaer provenance seedlings than those of Yinchuan provenance. With the increase of Na Cl concentration,the Mg2 ＋content in leaf gradually decrease,but the Mg2 ＋content in root increased 22. 8 64. 4% after salt stress for 7 days,and Alaer provenance seedlings increased more than Yinchuan provenance. After 30 days,there was non- significant difference with the control group on the Mg2 ＋content of root. K＋selective absorption of E. angustifolia L. seedlings significantly increased with increasing salt concentration of the media at the 7th days,whereas not obvious at the 30 th days. When the concentration of Na Cl in the media increased,the change of K＋selective transportation was not significant. [Conclusion]E. angustifolia L.seedlings increase Mg2 ＋content and K＋selective absorption in the roots at the early stage of salt stress to adapt saline environment. The salt-tolerance E. angustifolia L. provenance can cut off more Na＋in roots and reduce Na＋content in leaves,which cause less K＋,Ca2 ＋and Mg2 ＋contents loss,especially the roots and leaves,so as to ensure that all kinds of metabolisms can go well.