绝大多数柑橘的成熟期集中于十月至十二月，市场销售、贮运和加工压力较大。生产中发现，雨旱季分明的地区，柠檬和葡萄柚在旱季之后可以大量开花，金柑和四季桔等花期也受控水调节，因此干旱可以影响部分柑橘的成花从而影响成熟期。为解析干旱调控成花的分子机理，课题组前期分析了干旱处理柠檬促进成花过程中的基因表达，结果显示FT/TFL1基因家族在这个过程中充当极其重要的角色。所以本项目拟对干旱调控柠檬等柑橘成花进行形态解剖，测定成花过程中的激素含量等生理指标，以探明其生理机制；利用不同程度的干旱和激素处理，调查FT/TFL1家族的时空表达；通过酵母单双杂交等分离上下游的调控基因，揭示基因与环境、基因与基因网络调控的机理；同时以超表达FT:GFP和干涉TFL1的转基因枳嫁接柠檬，研究其形态和生理变化。本项目的顺利开展不但可将柑橘成花机理的研究引向深入，还可为砧穗互作以及利用转基因材料生产非转基因果实探索新路。

The majority of citrus ripening periods are concentrated from October to December, resulting to greater pressure on market sales, storage and processing. In the area of rainy season and dry season, lemon and grapefruit can be blossomed after the dry season, and the flowering time of kumquat and calamondin is also controlled by water stress during citrus cultivation and production process. Therefore, the drought can affect the flowering of some citrus trees and the ripening period. In order to analyze the molecular mechanism of drought regulation and flowering, the gene expression of lemons was studied by drought treatment during flower induction process, the results showed that FT/TFL1 gene family played an extremely important role in the process of drought-treated lemon to promote the process of flower formation. To analyze its physiological mechanism, this project plans to the determination of morphological and anatomical, hormonal content and other indicators during lemon flowering process; The temporal and spatial expression pattern of FT/TFL1 gene family will be also investigated by real-time PCR under different degrees of drought and hormone treatments; Meanwhile, this study attempt to identify some proteins and transcription factors which have interaction with the member of FT/TFL1 gene family and to get further functions for the study of flowering signal pathway by yeast two-hybrid assays and yeast one-hybrid assays. In addition, lemon will be grafted up/down to transgenic trifoliate orange carried fusion gene of FT:GFP driven by CaMV 35S promoter and TFL1 RNAi, respectively, and investigated its morphological and physiological changes. The results will reveal whether flowering signals are transmissible between shoot apical meristem and leaves, as well as their forms, transmission route and distribution rule, so as to enhance our knowledge about plant phase development and flowering transition. Also, the fulfill of this project will do helpful as reference for study of the interaction between rootstock and scion, and provide theoretical foundation for accelerating fruit breeding and utilization of transgenic plants to produce un-transgenic fruit.