高温胁迫对菊花电阻抗图谱参数的影响

以菊花(Chrysanthemum morifolium)‘神马’扦插苗茎段和叶片为材料,测定其高温胁迫(25~50℃)下电阻抗图谱参数的变化,通过膜透性(相对电导率)与电阻抗图谱参数间的相关性,来证明电阻抗图谱法研究菊花耐热性的有效性。结果表明:随着温度升高,茎叶的胞外电阻、胞内电阻、弛豫时间呈现先增加,后急剧下降的趋势,而弛豫时间分布系数变化趋势为不规则下降。茎叶相对电导率是随着温度的升高先增加后降低再急剧增加。经过菊花茎叶电阻抗图谱参数拟合菊花的耐热性与相对电导率表示的耐热性温度极为接近。相关分析表明,高温胁迫下菊花茎叶相对电导率与胞外电阻(茎p<0.01,叶p<0.05)、弛豫时间(p<0.05)之间有显著的相关。由此可见,胞外电阻和弛豫时间是测定菊花耐热性的适合参数。

Effect of High Temperature Stress on Electrical Impedance Spectroscopy Parameters of Chrysanthemum

To study the heat tolerance of chrysanthemum(Chrysanthemum morifolium),the electrical impedance spectroscopy(EIS) parameters of chrysanthemum’Jinba’stems and leaves under high temperature stress(25℃ to 50℃) were measured,and the relationship between electrolyte leakage(relative conductivity) and EIS parameters was analyzed.The results showed that extracellular resistance,intracellular resistance,and relaxation time of stems and leaves first increased and then decreased significantly with increasing temperature.However,the trends of distribution coefficient of relaxation time of stems and leaves showed irregular decrease under high temperature stress.The relative conductivity of chrysanthmum increased,then decreased,and finally increased significantly.Heat tolerance of chrysanthemum estimated by EIS parameters was close to that assessed by the EL method.Significant correlation between relative conductivity and extracellular resistance(stem: p<0.01,leaf p<0.05) and relaxation time(p<0.05) of stem and leaf were found.In conclusion,extracellular resistance and relaxation time could be suitable parameters for determining heat tolerance of chrysanthemum.