NaCl胁迫对2个杨树品系扦插苗生长及体内离子含量和运输的影响

Effect of NaCl stress on growth and ion content and transport in cutting seedling of two lines of Populus spp.

以杨树(Populus spp.)品系"南杨1号"(Nanyang No.1)和"南杨2号"(Nanyang No.2)为实验材料,研究了不同浓度(0、75和150 mmol.L-1)NaCl胁迫条件下2个杨树品系扦插苗生长及不同器官中离子(N、P、K+、Na+、Ca2+、Mg2+和Cl-)含量与运输的差异。结果表明:随NaCl浓度的提高,2个杨树品系的单株干质量以及"南杨1号"的根冠比均逐渐降低,但"南杨2号"的根冠比呈现先增大后减小的趋势;除P和Mg2+含量外,2个品系根、新生枝条和叶片中营养元素的含量均逐渐降低,Na+和Cl-含量以及Na+/K+和Na+/Ca2+比值均逐渐增加,但Na+和Cl-含量以及Na+/K+和Na+/Ca2+比值的增幅在根中均最高、在叶片中均最小。在150 mmol.L-1NaCl胁迫条件下,2个品系的单株干质量和根冠比以及根、新生枝条和叶片中N、P、K+、Ca2+和Mg2+含量均最低,Na+和Cl-含量以及Na+/K+和Na+/Ca2+比值均最高,且与对照有显著差异。在NaCl胁迫条件下,2个品系从根到新生枝条、从新生枝条到叶片的离子运输相对选择性比率RSK+,Na+和RSCa2+,Na+基本上均小于对照,其中,从根到新生枝条的RSK+,Na+和RSCa2+,Na+均大于从新生枝条到叶片。总体上看,在NaCl胁迫条件下"南杨2号"的单株干质量和根冠比、各器官的N和P含量、不同器官间的RSK+,Na+和RSCa2+,Na+均高于"南杨1号","南杨2号"各器官的Na+和Cl-含量以及Na+/K+和Na+/Ca2+比值的增幅均低于"南杨1号"。综合分析结果表明:NaCl胁迫对2个杨树品系扦插苗的生长及体内离子的分布及运输均有一定的影响,但总体上看,"南杨2号"对NaCl胁迫的耐性优于"南杨1号"。

Taking two new lines of ＂Nanyang No. 1＂ and ＂Nanyang No. 2＂ of Populus spp. as the experimental materials, differences of growth and content and transport of ions （ N、P、K^＋、Na^＋、Ca^2＋、Mg^2＋ and Cl^-） in different organs of cutting seedlings of two lines were researched under NaC1 stress with different concentrations （0, 75 and 150 mmol·L^-1）. The results show that with rising of NaC1 concentrations, dry weight per plant of two lines and root-shoot ratio of ＂Nanyang No. 1＂ are gradually reducing, but root-shoot ratio of ＂ Nanyang No. 2＂ appears the trend of firstly increasing and then reducing; in root, new branch and leaf of two lines, contents of nutrient elements all are gradually decreasing except P and Mg^2＋, and contents of Na^＋ and C1^- and ratio values of Na^＋/K^＋ and Na^＋/Ca^2＋ are gradually increasing but their increasing ranges are the highest in root and the lowest in leaf. Under stress of 150 mmol·L^-1 NaC1, dry weight per plant and root-shoot ratio, contents of N, P, K^＋, Ca^2＋ and Mg^2＋ in root, new branch and leaf of two lines all are the lowest, and contents of Na^＋ and C1^- and ratio values of Na^＋/K^＋和 Na^＋/Ca^2＋ all are the highest with the significant difference compared to the control. Under NaC1 stress, the relative selectivity ratio RSK^＋,Na^＋ and RSCa^2＋,Na^＋ of ion transporting from root to new branch and from new branch to leaf of two lines almost are lower than those of the control, in which, RSK^＋,Na^＋ and RSCa^2＋,Na^＋ from root to new branch all are bigger than those from new branch to leaf. Generally, under NaC1 stress, dry weight per plant, root-shoot ratio, N and P contents, and RSK^＋,Na^＋ and RSCa^2＋,Na^＋ among different organs of ＂Nanyang No. 2＂ all are higher than those of ＂Nanyang No. 1 ＂, while increasing ranges of Na~ and C1- contents, ratio values of Na^＋/K^＋ and Na^＋/Ca^2＋ in different organs of ＂Nanyang No. 2＂ all are lower than those of ＂ Nanyang No. 1 ＂. Comprehensive analysis result indicates that NaC1 stress has a certain effect on growth and ion distribution and transport in cutting seedlings of two lines of Populus spp., but generally, the resistance of ＂Nanyang No. 2＂ to NaCl stress is superior to that of ＂Nanyang No. 1＂