澳洲坚果在果实发育初期约80%以上已完全受精的幼果发生脱落，导致产量较低，影响产业发展。前期研究表明，澳洲坚果早期果实发育期间发生碳水化合物饥饿胁迫，导致ABA含量增加，诱发严重落果。但碳水化合物饥饿对ABA的调控机理及其对落果的作用机制尚未明确。本研究拟在果实发育早期，对比树体遮荫及结果枝环剥+摘叶所引起的饥饿胁迫处理与主枝环剥及喷施保果叶面肥以增强果实碳素营养处理，并结合ABA抑制剂与糖信号受体阻断剂处理果实，研究果实不同组织及果柄离区内ABA与糖组份的含量变化，着重分析参与糖响应的酶基因(HXK、TPS、TPP和SnRK1)及ABA合成的关键调控酶基因(NCED、AAO和BG)的时空表达特性，以期明确早期落果与糖组份、糖响应酶及ABA合成之间的联系，探明诱导果实脱落的糖信号及其对ABA的调控机理，揭示碳水化合物饥饿诱导澳洲坚果早期落果的分子生理机制，为澳洲坚果保果增产提供理论基础。

More than 80% the fertilized fruitlets abscise during the early fruit development of macadamia , which results in the low yield and affects the development of macadamia industry. Our early researches showed that carbohydrate starvation occured in the early fruit and caused a increased ABA level and a serious fruit abscission. However, this possible mechanism of carbohydrate starvation regulating ABA and the early fruit abscission are not yet clear. This study will analyse the changes of ABA levels and sugar component contents in the different tissues of fruit and the abscission zone of carpopodium, and focus on the analysis of the time and space expression features of the genes (HXK, TPS, TPP and SnRK1) related to sugar response and the key genes (NCED, AAO and BG) regulating ABA biosynthesis, through comparing the fruit starvation stress induced by tree shading and the bearing branch girdling plus defoliation treatments with the improving fruit carbon nutrition by girdling the main branch and spraying the foliage fertilizer treatments and combining with ABA synthesis inhibitors and sugar signal receptor blockers treating fruitlets during the early fruit development of macadamia. It might contribute to understanding the relationship of sugar component, sugar response enzymes, ABA biosynthesis and the early fruit drop of macadamia, ascertaining the sugar signal inducing fruit abscission and the mechanism of sugar signal regulating ABA, revealing the molecular and physiological mechanism of carbohydrate starvation inducing the early fruit abscission in macadamia, and providing theoretical basis for alleviating fruit drop in macadamia production.