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.