以流苏2年生苗木为材料,测定其叶片与茎在NaCl胁迫(0,0.4%,0.8%, 1.2%)下的电阻抗图谱参数和电导率的变化,分析电阻抗图谱参数与电导率间的相关性,以讨论在NaCl处理下用电阻抗图谱法研究流苏受胁迫程度的有效性。结果表明: 1)随着NaCl浓度的升高,叶片电导率显现逐渐升高或先升高后下降的趋势,茎的表现不明显; 随着胁迫时间的延长叶片和茎电导率,整体均显现逐渐升高或先升高后降低的趋势。流苏茎的耐盐性强于叶片。2)随着NaCl浓度的升高,流苏叶片和茎的高频电阻率 r 、胞内电阻率 ri和弛豫时间 τ 呈现先增大后减小或逐渐减小的特征; 随着胁迫时间的延长叶片和茎的各处理的电阻抗图谱参数均在胁迫15天时出现最低值。相关分析表明: 流苏对0.8%以上NaCl浓度胁迫敏感,用电阻抗图谱参数可以表征流苏受NaC1胁迫的程度,且用EIS参数胞内电阻率 ri、高频电阻率 r 来表征叶耐盐特性,用胞内电阻率 r i、弛豫时间 τ 来表征茎耐盐特性。 ri为评价流苏叶和茎NaC1胁迫的最佳参数。
The electrical impedance spectroscopy (EIS) parameters and relative electrolyte leakage leaves and stems of of Chinese Fringetree ( Chionanthus retusus ) leaves and stems under NaCl stress (0.4%, 0.8% and 1.2%) (water as the control) were measured. The validity of EIS parameters was testified by comparing the relation ship between these parameters and relative electrolyte leakage. The results showed that: 1) With the increasing in concentration of NaCl, the relative electrolyte leakage of the leaves increased gradually or increased firstly and then decreased. However the stems did not obvious responses of the leakage to salt stresses. With increasing duration of the stress, the relative electrolyte leakage of leaves and stems all increased gradually or increased firstly and then decreased. The salt resistance of stems was higher than that of leaves. 2) Specific high-frequency resistance r , intracellular resistance riand relaxation time τ of leaves and stems decreased gradually or increased firstly and then decreased with the increasing NaCl concentration. The EIS parameters in each treatment gradually decline with the treatment time and reached to the salt the lowest level in 15 days NaCl. The correlation analysis indicated that C. retusus was sensitive to the salt stress over 0.8% and EIS parameters could effectively reflect the extent of C. retusus stressed by NaCl. Specific intracellular resistance riand high-frequency resistance r could characterize the resistant to salt of C. retusus leaves, and ri and relaxation time τ could characterize the resistant to salt of the stems. According to a path coefficient of EIS parameters, riwas the best parameter for evaluating the NaCl stress of leaves and stems in C. retusus.