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^-1 NaCl 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RS_K+,Na+和RSC_a2+,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RS_K+,Na+和RS_Ca2+,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⁺, Ca²⁺,Mg²⁺ and Cl^-) in different organs of cutting seedlings of two lines were researched under NaCl stress with different concentrations (0, 75 and 150 mmol·L^-1 ). The results show that with rising of NaCl 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 Mg²⁺, and contents of Na+ and Cl^- and ratio values of Na⁺ / K⁺ and Na⁺ / Ca²⁺ are gradually increasing but their increasing ranges are the highest in root and the lowest in leaf. Under stress of 150 mmol·L^-1NaCl, dry weight per plant and root-shoot ratio, contents of N, P, K⁺, Ca²⁺ and Mg²⁺ in root, new branch and leaf of two lines all are the lowest, and contents of Na⁺ and Cl^- and ratio values of Na⁺ / K⁺和Na⁺ / Ca²⁺ all are the highest with the significant difference compared to the control. Under NaCl stress, the relative selectivity ratio RS_K+,Na+ and RS_Ca2+,_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, RS_K+,_Na+ and RS_Ca2+,Na⁺ from root to new branch all are bigger than those from new branch to leaf. Generally, under NaCl stress, dry weight per plant, root-shoot ratio, N and P contents, and RS_K+,Na+ and RS_Ca2+,_Na+ among different organs of “Nanyang No. 2”all are higher than those of “Nanyang No. 1”, while increasing ranges of Na⁺ and Cl^- contents, ratio values of Na⁺ / K⁺ and Na⁺ / Ca²⁺ in different organs of  “Nanyang No. 2”all are lower than those of “Nanyang No. 1”. Comprehensive analysis result indicates that NaCl 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”.