Frost hardiness accuracy assessment by electrical impedance spectroscopy in Catalpa spp. during frost hardeningAuthor(s): Bao Di, Ji Qian, Yu Meng, Gang Zhang, Di-Ying Xiang, Ming Guo
Three species of Catalpa spp. were used to measure soluble sugar content and membrane permeability as well as electrical impedance spectroscopy (EIS) of stems during frost hardening. The relations between parameters of the EIS and corresponding soluble sugar content and membrane permeability were analyzed respectively. The comparatively satisfying correlated EIS parameters were selected for estimating frost hardiness of stems. Also the conventional conductivity method was applied to estimate frost hardiness of stem in three species of Catalpa spp.. The most outstanding parameter of the EIS was chosen by comparison of these two estimation frost hardiness methods, for the purpose of testing the accuracy of frost hardiness assessed by means of the EIS method. Those study results reveal: 1) During frost hardening, soluble sugar content and membrane permeability increased; 2) Shapes of impedance spectra were changed in different species of Catalpa spp. stem; 3) The EIS parameters of specific low-frequency resistance r1 and specific extracellular resistance re had significant positive correlations with soluble sugar content as well as membrane permeability. Among them r1 rank on the top for frost hardiness of stem with estimation accuracy of 81.83%. In conclusion, the EIS data can be used to assess frost hardiness of stem in three species of Catalpa spp. with greater reliability.