中文摘要：

【目的】弄清不同发育时期杏花、幼果过冷却点和结冰点变化，不同花器官过冷却点和结冰点的差异，为杏花期霜冻害机理的研究提供基础数据。【方法】以3个杏品种为试材，利用能准确模拟自然界霜夜降温过程的人工霜箱，测定不同发育时期花器官、幼果的过冷却点、结冰点，统计杏花器官受冻情况。【结果】随杏花发育进程的推移，3个杏品种自大蕾期至幼果期过冷却点、结冰点呈现明显上升趋势，表明抗寒力下降；不同品种、不同花器官过冷却点、结冰点存在差异，品种间表现为花器官过冷却点、结冰点越低，抗性越强，从过冷却点到结冰点的平均温度“跃升”值越大；过冷却点并不表示一个确定值，而是一个范围。花瓣过冷却点频率分布较雄蕊、雌蕊分散；杏花器官通过保持过冷却状态回避低温伤害，但对结冰十分敏感，一旦结冰，升温后花器官均受害而褐变。【结论】不同发育时期、不同品种不同花器官过冷却点和结冰点存在差异。

英文摘要：

[ Objective ] The aim of this study is to provide basic data for study on the mechanism of frost by making clear the changes of supercooling poin （SCP） and freezing point （FP） in flower and young fruit at different developmental stages of apricot, and the differences among floral organs. [Method] Using an artificial climate chamber, SCP and FP in flower and young fruit at different developmental stage and the degree of freezing damage of floral organs in three apricot cultivars were studied.[ Result ]With the development of flower buds, SCP and FP increased, which indicated that cold resistance decreased. SCP and FP varied with different floral organs. For different apricot cultivars, the lower SCP or FP of floral organs was, the more resistance the cultivar had, and the lager the interval between SCP and FP was. SCP was not a constant value, but a range. The frequency of SCP in petals was more dispersing than that in stamens and pistils. Floral organs could maintain a supercooling state to avoid ice formation, but they were sensitive to freezing. Once floral organs froze, they turned brown after thawing. [ Conclusion ] SCP and FP varied with different developmental stages and different floral organs.