Relation Between Parameters Of Electrical Impedance Spectroscopy And Those Of Physiology In Pinus Bungeana Shoots And Needles Of Different Provenances

Pinus bungeana Zucc. is an evergreen arbor and the only kind of three needles pine in Eastern Aria. It is a tree originally produced in China, and is a precious tree species for its beauty and white bark. It has high cold-resistance and the main ornamental tree species in Northern China. During dehardening (from March 2007 to May 2007), we studied the parameters of electrical impedance spectroscopy (EIS), frost hardiness (FH) and the physiological parameters of one-year-old shoots and needles of P. bungeana in an 9-year provenance field trial at Shisanling Nursery in Beijing with provenances of Mangshan of Beijing, Xiaoyi of Shanxi and Liangdang of Gansu. FH of shoots was measured by means of EIS and electrolyte leakage (EL); FH of needles was measured by means of EL, visual scoring of damage (VSD) and chlorophyll fluorescence (CF), respectively. The activities of Superoxide Dismutase (SOD), the activities of Peroxidase (POD), the content of Malondialdehyde (MDA), the content of Soluble Protein, the content of Proline, the chlorophyll concentration, the dry weight/fresh weight ratio (DW/FW) as well as the maximum photochemical efficiency of photosystem II (F_v/F_m) of needles wer_e measured. During frost hardening (from September 2007 to January 2008), we studied the parameters of EIS, and the content of soluble sugar and starch. The aim of the study was to find the change pattens of EIS parameters, FH and the physiological parameters, and to verify the relation between these parameters of EIS and FH, and between parameters of EIS and those of physiology.The main results ar_e as follows:1. With the enhancement of the FH, some changes had taken place for the EIS parameters and electrical impedance spectra of shoots and needles during dehardening.2. During dehardening, EIS parametersβand the specific extracellular resistance r_e in non-frost-exposed needles correlated negatively with the content of proline; and ther_e was a positive relation between the membrane time constantÏ„_m and the content of soluble protein. Similar change patterns were found between the specific intracellular resistance ri and the content of MDA; between theÏ„_m and the DW/FW. In the early stage of dehardening, parameters r_e andβvaried similily with soluble protein.3. During dehardening, DW/FW and EIS parameters had no significant correlation. 4. Relations between the F_v/F_m and the EIS parameters r_e as well asβof the non-frost-exposed needles were found during dehardening. The FH of the needles measured by r_e and other methods after artificial freezing tests correlated to F_v/F_m of non-frost-exposed needles.5. During dehardening, the FH assessed by r_e andÏ„_m after artificial freezing treatment correlated to the content of chlorophyll and the content of Proline.6. During dehardening, the FH of each provenance decreased sharply. The FH of shoots and needles which were measured by means of EIS, EL, VSD and CF methods presented similar tendency. However, in the beginning of dehardening, the FH was under estimated by the EIS than by the other methods.7. During dehardening, for non-frost-exposed needles, the changes in the re,β, andÏ„_m of needles had opposite trend with the FH, and also displayed a high correlation with FH assessed by EL, CF, VSD and EIS.8. During frost hardening, there wer_e significantly negative relations between soluble sugar content of needle andβ, starch content of needle andÏ„_m as well as r_e, starch content of shoots and r_i, relaxation timeÏ„₁ as well as re; ther_e wer_e significantly positive relations between soluble sugar content of shoots andÏ„₁, and soluble sugar content of needle andÏ„_m.