Abstract:

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 r_iand 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 r_iand high-frequency resistance r could characterize the resistant to salt of C. retusus leaves, and r_i and relaxation time τ could characterize the resistant to salt of the stems. According to a path coefficient of EIS parameters, r_iwas the best parameter for evaluating the NaCl stress of leaves and stems in C. retusus.

Key words: Chinese Fringetree (Chionanthus retusus), NaCl stress, electrical impedance spectroscopy, electrolyte leakage