Salt Resistance Detection Of Chinese Frigetree (Chionanthus Retusus) Based On Electrical Impedance Spectroscopy

Chinese Fringetree (Chionanthus retusus), a species of deciduous shrub or small tree, belongs to Oleaceae, and genus Chionanthus. Due to its high application value in landscaping, study of salt resistance has a positive guide for landscaping in saline-alkali area. In this paper, the effects of NaCl stress on parameters of electrical impedance spectroscopy (EIS), the growth indexes and the physiological indicators of Chinese Fringetree were investigated. The aim of the study was to verify the relation between the parameters of EIS and salt tolerance, and between parameters of EIS and those of physiological indicators of Chinese Fringetree under NaCl stress.The main results are as follows:1. With the increasing in concentration of NaCl and increasing in stress time, change of electrical impedance spectroscopy and EIS parameters of Chinese Fringetree occurred.2. Under different NaC1 tress, intracellular resistance (r) had high correlation with the relative conductivity (R2>0.50). There were high correlations between specific resistance (r, r1), intracellular resistance (r1), extracellular resistance (re) and water content of leaf, under NaCl stress (R2>0.50). There were high correlations between intracellular resistance (r1) and chlorophyll content, under NaCl stress (R2>0.50). There were high correlations between relaxation time (r) and SOD activity, under NaCl stress (R>0.50). Under different NaCl stress, specific resistance (r), intracellular resistance (ri), relaxation time (t), distribution coefficient of r (ψ) had high correlation with POD activity (R2>0.50). Under different NaCl stress, specific resistance (r1), extracellular resistance (re) had high correlation with MDA content (R2>0.50). Under different NaCl stress, specific resistance (r), intracellular resistance (ri)had high correlation with protein content and proline content (R2>0.50).3. According to correlation analysis, between parameters of EIS and those of physiological indicators, ri as the best parameter for evaluating the NaCl stress of Chinese Fringetree.4. Under different NaCl stress, the results showed that treatment of 0.8% was the critical value of salt resistance in two-year old Chinese Fringetree.5. Under NaCl stress, different organs (leaf and stem) had different reaction between electrical impedance parameters and relative electrolyte leakage of Chinese Fringetree. 6. Most of the EIS parameters showed the minimum values appeared in the first 15 days of the treatments, indicating that the first 15 days of the treatments is the shreshold days of salt resistance.