花期气温变化下库尔勒香梨脱萼果与宿萼果形成机理研究

The Korla fragrant pear fruit is characterized with fascinating flavor, thin pericarp, crispness, juicy and sweet, and extremely long-storage.Korla pear is one of the most characteristc fruits in Xinjiang with Turpan grapes and Kumul melon. However, abscising or persisting of calyx occurred in different order and the same inflorescence on tree impact the quality of the fruit. This research, based on the recent studies about relationship between calyx abscission and different air temperature during flowering stage, aim to explore the scientific issues 'why the abscising and persisting of Korla fragrant pear calyx have been impacted under different temperature conditions during the flowering stage by focusing on the dynamic changes of endogenous hormones in fruits such as gibberellin, ethylene during fruit formation, and finding the correlation between distribution of boron, calcium and and the formation of abscission, and studying the activity changes of enzymes that related to abscission such as cellulase, pectinase.This research has an important theoretical significance on revealing the abscising and persisting mechanism of Korla fragrant Pear calyx.

库尔勒香梨果实具有特殊香味，皮极薄，肉酥脆，汁多甜美，极耐贮藏，与吐鲁番葡萄、哈密瓜齐名成为新疆三大名优瓜果特产。然而，库尔勒香梨同一棵树上同一花序不同序位的花的萼片有的自动脱落，有的则宿存，产生宿萼﹑脱萼等果形。本项目在库尔勒香梨花期气温变化与萼片脱落、宿存的相关性研究的基础上，以库尔勒香梨花期气温变化为环境条件，通过对库尔勒香梨幼果形成中赤霉素、乙烯等内源激素动态变化；幼果和萼片内的硼、钙等营养元素和蔗糖等同化物的分配与萼片离层形成的关系；纤维素酶、果胶酶等与离层相关酶活性变化进行研究，探讨花期不同气温条件下，为何库尔勒香梨萼片脱落与宿存受到影响等科学问题，进一步揭示库尔勒香梨萼片脱落与宿存的机理具有重要的理论意义。

香梨的果实分为宿萼果和脱萼果，宿萼果一般表皮粗糙，石细胞多，果核大，味淡，而脱萼果一般是果形端正，果面光洁，石细胞少，果核小，风味好，很受消费者欢迎。实际生产中发现香梨花期日平均气温较低的年份，同比以往温度较高的年份脱萼果率有所上升，针对花期气温变化下库尔勒香梨脱萼果与宿萼果形成机理研究几乎没有报道。本研究通过选择气温变化相差大的果园以及在果园建造设施人为设定温度，研究初花期和盛花期不同气温下，坐果始期幼果、离层形成期的离层形成及未形成幼果、萼片脱落期的脱萼、宿萼幼果的内源激素动态变化；氮、磷、钾、钙、镁、铁、锌等无机营养元素和蔗糖等同化物的分配与萼片离层形成的关系；纤维素酶、果胶酶等与离层相关酶活性变化进行了详细研究， 该项目的研究为揭示花期气温变化对库尔勒香梨果实萼片的脱落与宿存的影响机理提供重要的理论依据，并为植物器官脱落研究提供了一条新的思路。同时在花期低温下出现的偏斜果进行了初步研究。