Effects of cold hardening on physiological indices related to cold tolerance in Ectropis obliqua pupaes
Author of the article:DUAN Xiao-Feng1, 3** WANG Xiao-Qing3 LI Pin-Wu2*** TIAN Jing-Tao1 PENG Ping3*** CHEN Shi-Chun3
Author's Workplace：1. Tongren Polytechnic College, Tongren 554300, China; 2. College of Horticulture, Sichuan Agricultural University, Ya’an 625014, China; 3. Tea Research Institute, Chongqing Academy of Agricultural Sciences, Yongchuan 402160, China
Key Words： Ectropis obliqua Prout, cold hardening, supercooling point, cold hardiness, physiological mechanisms, stress-tolerance enzymatic activities
Abstract：[Objectives] To explore the physiological mechanisms by which Ectropis obliqua (Prout) responds to cold hardening. [Methods] E. obliqua pupae were exposed to 0℃ and 5℃ for 2 h (rapid cold hardening), or 5℃ for 24 h and 48 h (cold acclimation). A thermocouple was used to measure supercooling points, and physiological indices related to cold tolerance were measured. [Results] The supercooling points and water content of E. obliqua pupae were significantly depressed, lipid and glycogen content significantly increased, protein content slightly increased, the activity of three protective enzymes (POD,CAT and SOD) significantly increased, and ATP activity was significantly depressed, by cold acclimation. The supercooling points of E. obliqua pupae were significantly depressed, water content slightly depressed, lipid, glycogen and protein content significantly increased, POD,CAT and SOD activity were significantly increased, and ATP activity significantly depressed, by rapid cold hardening. [Conclusion] The observed changes in water, lipid, glycogen, protein content and enzymatic activity suggest that cold acclimation and rapid cold hardening can make E. obliqua more cold tolerant. These results can improve understanding of the overwintering strategies of E. oblique, estimating the distribution of this species based on climatic conditions, and provide an important basis for predicting mortality and forecasting abundance in the field, all of which are important for improving prevention and control measures for this pest.