| 摘要: |
| 【目的】探讨西伯利亚白刺根系生长特征及根系中K+/Na+平衡与NaCl胁迫的关系。【方法】以西伯利亚白刺水培幼苗为材料，研究0(对照)，100，200，300，400 mmol/L NaCl处理对其植株生物量积累、分配，根系形态特征及根系中K+、Na+、Cl-积累情况的影响。【结果】随着NaCl浓度的升高，西伯利亚白刺幼苗根、茎、叶、冠层生物量和根冠比均呈先升高后下降的趋势，其中最大值均出现在200 mmol/L NaCl处理下，而400 mmol/L NaCl处理明显降低了西伯利亚白刺幼苗根、茎、叶、冠层生物量。随着NaCl浓度的升高，西伯利亚白刺幼苗根长、平均直径、表面积及根尖数均呈先升高后下降的趋势，其中最大值均出现在200 mmol/L NaCl处理下，300 mmol/L NaCl处理下西伯利亚白刺根系平均直径和表面积较对照略有增加，但差异不显著，而400 mmol/L NaCl处理下根系生长受到显著抑制。不同浓度NaCl处理下，西伯利亚白刺幼苗根系对Na+、Cl-和K+的吸收增加，但K+/Na+随着NaCl浓度的升高逐渐降低。【结论】低浓度(≤200 mmol/L) NaCl处理下，西伯利亚白刺可以通过增加根系生物量、总长度、表面积、根尖数促进根系生长，并通过增加根系离子含量提高根系渗透势差来适应盐胁迫；高盐(400 mmol/L NaCl)处理下则通过提高根系对K+的选择性吸收来降低根系中K+/Na+，从而降低单盐毒害作用，提高其耐盐性。 |
| 关键词: NaCl胁迫 西伯利亚白刺 根系生长 K+/Na+平衡 |
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| 基金项目:国家林业局引进国际先进林业科学技术项目（2015-4-12）；中央级公益性科研院所基本科研业务费专项（CAFYBB-2016MB007） |
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| Effect of NaCl stress on root growth and K+/Na+ balance of Nitraria sibirica Pall. seedlings |
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TANG Xiaoqian,LI Huanyong,YANG Xiuyan,et al
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| Abstract: |
| 【Objective】This study investigated the role of salinity in root growth characteristics and K+/Na+ balance of Nitraria sibirica Pall.seedlings.【Method】The plant biomass accumulation and distribution,root morphology characteristics as well as K+,Na+ and Cl- accumulation in root of N. sibirica seedlings under different NaCl levels (0(CK),100,200,300 and 400 mmol/L) were investigated through hydroponic experiment in greenhouse.【Result】The biomass accumulations in root,stem and leaf,and root/sheet ratio of N. sibirica increased first and then decreased with the increase of NaCl concentration,and the maximum values were at 200 mmol/L NaCl treatment.The 400 mmol/L NaCl treatment significantly reduced the biomass accumulations in root,stem and leaf.With the increase of NaCl concentration,total length,surface area,average diameter and root tip number of N.sibirica roots increased first and then decreased,and the maximum values were at 200 mmol/L NaCl treatment.Compared with the control,the surface area and average diameter of roots were slightly increased in the 300 mmol/L NaCl treatment without significant difference.The growth of N.sibirica roots were significantly inhibited by 400 mmol/L NaCl treatment. With the increase of NaCl concentration,Na+,Cl- and K+ contents in roots of N. sibirica were increased compared with control,but K+/Na+ ratio decreased.【Conclusion】Low concentration (≤200 mmol/L) of NaCl significantly enhanced root growth of N. sibirica possibly via increasing biomass accumulation,total length,active absorbing area,tip number of roots and adapted salt stress by increasing ion content and osmotic potential difference.High concentration (400 mmol/L) of NaCl significantly inhibited root absorption unit via decreasing biomass accumulation,total length and tip number of roots,and decreasing K+/Na+ in roots.Thus,high concentration can reduce toxic effect of single salt and maintain relative balance of ions. |
| Key words: NaCl stress Nitraria sibirica Pall. root growth K+/Na+ homeostasis |
