盐碱胁迫下金叶接骨木根系K含量模型构建﹡

摘要

Objective]Sambucus canadensis was used as experimental material in this study. To simply and fastly predict K content in roots of Sambucus canadensis under salinity and alkalinity stress,salinity and alkalinity resistance of this plant roots was measured by electrical impedance spectroscopy ( EIS ) and electrolyte permeability methods and the estimation model of K Content of their roots was establish. [Method]The electrical impedance spectroscopy, cell membrane permeability and the change of K content in roots during different concentrations of salinity-alkalinity stress were studied. The corrections between EIS parameters and K content were analyzed using linear and nonlinear regressions. The estimation model was constructed using the best EIS parameter and the model accuracy was tested.[Result]During the salinity and alkalinity stress,compared with control,the K content of Sambucus canadensis roots treated by different concentrations of salinity-alkalinity significantly decreased(P≤0. 05). As the extension of salinity-alkalinity stress time, the relative conductivity of the roots under different stress tended to rise and significantly increased compared with control ( P≤0. 05 ) . The spectra of electrical impedance changed in roots of Sambucus canadensis during salinity-alkalinity stress;The EIS parameter τ was the best for assessing K content of root. The best model was y =0. 005 5x3 -0. 232 8x2 +2. 638 8x + 15. 877 with the precision accuracy of 91. 73%.[Conclusion]The model y =0. 005 5x3 -0. 232 8x2 +2. 638 8 x+ 15. 877 with best precision accuracy constructed with EIS parameter τ can be used to fastly and accurately forecast K content in roots of Sambucus canadensis under salinity and alkalinity stress.%【目的】以金叶接骨木为试验材料，用电阻抗图谱( EIS)法和电解质渗透率法测定根系抗盐碱性并构建其根系 K含量模型，为简单快速地预测盐碱胁迫下金叶接骨木根系的 K 含量提供技术支持。【方法】研究不同浓度盐碱胁迫下金叶接骨木根系 EIS图谱、细胞膜透性以及 K 含量的变化，将根系 EIS 参数与相应的 K 含量进行线性和非线性回归分析，选取最佳的 EIS参数构建估测模型，并对模型进行精度检验。【结果】在胁迫处理期间，各浓度处理金叶接骨木根系 K含量均显著低于对照( P≤0.05)；随着盐碱胁迫时间延长，各浓度处理下金叶接骨木根系的相对电导率呈现上升趋势，且均显著高于对照(P≤0.05)；随着盐碱胁迫时间延长，各浓度处理下金叶接骨木根系的电阻抗图谱变化不同；弛豫时间τ为估测金叶接骨木根系 K 含量的最佳 EIS参数，最佳估测模型为 y =0.0055x3－0.2328x2+2.6388+15.877，预测精度达到91.73%。【结论】利用EIS参数构建的金叶接骨木根系K含量模型 y =0.0055x3－0.2328x2+2.6388x+15.877预测精度高，可以用于快速准确预测盐碱胁迫下金叶接骨木根系 K含量的变化。