NaCl胁迫下小胡系杨树的离子吸收规律与分配特征研究

Regularities of the Ion Uptake and Allocation Characteristics for Populus simonii×P.euphratica Varieties under NaCl Stress

采用不同浓度的NaCl溶液胁迫处理‘小胡杨’(XHu)和‘辽胡杨1号’(LHu-1)当年生扦插苗,测量植株根、茎、叶中Na+、K+、Cl-含量,研究其不同部位的离子选择性吸收规律及离子分配特征,为进一步评价和筛选优良耐盐小胡系杨树品种提供理论依据。结果表明:随着盐浓度的升高,2个小胡系杨树品种苗木受害程度逐渐增加,根、茎和叶部Na+含量以及根向茎选择性运输系数(茎SK,Na)升高,全株K+/Na+比值以及茎向叶选择性运输系数(叶SK,Na)下降;XHu在盐胁迫条件下叶片厚度增加,最大为291.45μm,是对照的1.27倍;NaCl胁迫使小胡系杨树根和叶中Na+含量高于茎,叶中K+含量高于根和茎;盐胁迫下,LHu-1茎、叶中K+含量以及XHu根中K+含量均升高,而LHu-1根中K+含量降低;盐胁迫只对XHu茎、叶部Cl-含量有显著性影响,低盐浓度下其茎中Cl-含量升高,而高盐浓度下其叶中Cl-升高。综合分析表明,NaCl胁迫下小胡系杨树主要是将Na+区隔在根中,并把K+运输至茎和叶中,从而缓解地上部分的盐害;XHu的耐盐能力总体上高于LHu-1。

In order to provide a theoretical foundation for evaluating and selecting excellent salt-tolerance varieties of Populus simonii × P. euphratica, we studied the regularities of ion selective uptake and ion allocation characteristics of P. simonii × P. eulhratica （XHu） and P. simonii × P. euphratica ＇Liaohu 1 ＇ （LHu-1） under different NaCl concentrations. The results indicated that,with the increase of salt concentration, the injurious degree of seedlings gradually increased, Na^＋ contents of root, stem,leaf and coefficient of selective transportation from root to stem （stem SK,Na） increased, the whole plant K^＋/Na^＋ and coefficient of selective transportation from stem to leaf （leaf SK,Na） descended. Leaf thickness of XHu gradually increased with the the increase of salt concentration, and the biggest leaf thickness was 291.45 μm for XHu,which was 1.27 times of the control. Na^＋ content of the root and leaf was higher than that of the stem, and K^＋ content of the leaf was higher than that of the root and stem under NaCI stress. Under salt stress,K^＋ content of the root for XHu and that of the stem and leaf for LHu-1 increased,but K^＋ content of root for LHu-1 decreased. Salt stress only had a significant effect on Cl^- content of the stem and leaf for XHu,and Cl^- content of the root incrased under low NaCl concentration,while decreased under high NaCl concentration. Comprehensive analysis showed under NaCl stress,the seedling mainly compartmented Na^＋ in root,and transported K^＋ to stem and leaf for P. simonii×P, euphratica,thus to remit the salt symptom of overground part,and the results indicated that XHu generally had stronger ability than LHu-1 in salt tolerance.