Effects of altitude and ice nucleating active bacteria on the super-cooling point of Evergestis extimalis Scopli (Lepidoptera: Pyralidida)
Author of the article:LAI You-Peng;LI Qiu-Rong;ZHANG Gui
Author's Workplace:Key Laboratory of Plateau Ecology and Agriculture, Key Laboratory of Agricultural Integrated Pest Management of Qinghai Province, Qinghai Academy of Agricultural and Forestry Sciences, Xining 810016, China;Key Laboratory of Plateau Ecology and Agriculture, Key Laboratory of Agricultural Integrated Pest Management of Qinghai Province, Qinghai Academy of Agricultural and Forestry Sciences, Xining 810016, China;Key Laboratory of Plateau Ecology and Agriculture, Key Laboratory of Agricultural Integrated Pest Management of Qinghai Province, Qinghai Academy of Agricultural and Forestry Sciences, Xining 810016, China
Key Words:altitude; ice nucleating bacteria; Evergestis extimalis Scopli; super-cooling point
Abstract:
[Objectives] To understand how cold tolerance is influenced by altitude and ice nucleating active bacteria (INA) in high altitude environments. 【Methods】 Field conditions were simulated in a laboratory to study the effects of varying the super-cooling point (SCP) and freezing point (FP) of Evergestis extimalis.【Results】 Super cooling point declined gradually with altitude. For example, the SCP of E. extimalis from Le Du (1 900 m ASL), Xing Ning (2 300 m ASL) and Huang Yuang (3 010 m ASL) were ﹣12.30,﹣13.39 and﹣14.56 ℃, respectively. Variation of SCP and freezing point were correlated with local temperature. The SCP of E. extimalis increased after INA treatment. E. extimalis in the following treatment groups; INA1-1 (Pseudomonas syringae), INA2-1 (P. syringae), INA3-1 (Erwinia pyrifoliae) and the control, had SCPs of -10.72, -13.73, -14.04 and -14.39 ℃, respectively in Feb. 2014. Mortality in the INA1-1, INA2-1, INA3-1 treatment groups and the control were 29.09%、36.17%、33.16% and 27.44%, respectively on Nov. 2013.【Conclusion】 The SCP of E. extimalis decreased with increasing altitude. INA treatment dramatically reduced mortality and increased the SCP of E. extimalis.