以17年生北京7号桃树枝条为试材，采用水培法，利用能准确模拟自然界霜夜降温过程的人工霜箱，测定桃盛花期花器、幼果的过冷却点、结冰点；同时对桃花器及幼果进行不同低温(15、0、-1、-2、-3 ℃)处理，测定桃花器渗透调节物质可溶性蛋白、脯氨酸、丙二醛(MDA)含量。结果表明，盛花期的花器过冷却点和结冰点均低于幼果，低温胁迫下渗透调节MDA含量随温度下降而增加，温度越低，MDA 含量上升趋势越明显，表现出一种应激反应；可溶性蛋白和脯氨酸含量均呈先升后降的趋势，表现为适应状。

Using 17-year old Beijing 7 peach tree branches as test material. The artificial frost box， which can accurately simulate the natural frost night cooling process and hydroponics was used to determine the over-cooling point and freezing point of the organs and young fruit in the flowering period. At the same time， peach blossom organ and young fruit were treated at different low temperatures(15 ℃， 0 ℃， -1 ℃， -2 ℃， -3 ℃) to determine the contents of soluble protein， proline and malondialdehyde(MDA) content. The results showed that the overcooling point and freezing point of flower tube were lower than young fruit in flowering stage， and the MDA content in osmotic regulation increased with the decrease of temperature under low temperature stress， the lower the temperature， the more obvious the rising trend of MDA content， which shows a stress response； The contents of soluble protein and proline increased first and then decreased， which was adaptive.

S662.1

国家现代农业桃产业技术体系建设专项资金资助(CARS-30-Z-17)；公益性行业(气象)科研专项“中国北方果树霜冻灾害防御关键技术研究”(GYHY201206023)。