开花时间是作物的重要农艺性状。植物开花时间近年节律（开花期）的研究已经十分深入，而近日节律（每日开花的时间）的研究囿于实验材料的限制，报道较少。有棱丝瓜和普通丝瓜的每日开花时间相差近12小时，为研究植物开花近日节律提供了良好的实验材料。为了探明这一现象的分子遗传机制，项目组前期完成了丝瓜高密度遗传图谱的构建、种间染色体渐渗系的建立、基因组BAC文库的建立等工作；同时利用近等基因系群体将丝瓜每日开花时间主效QTL位点QFT1定位于0.32cM的范围内。本项目拟通过构建更大的定位群体，克隆QFT1基因；利用转基因功能互补、超量表达和基因编辑实验验证基因功能；进一步通过基因结构分析、表达模式分析、代谢通路分析，研究QFT1调控丝瓜开花时间的机理。以期揭示有棱丝瓜和普通丝瓜每日开花时间不同的分子机制，为植物每日开花时间调控建立理论模型；同时为下一步打破丝瓜种间花期隔离、利用种间杂种优势奠定基础。

Flowering time is an important agronomic trait of the crop. In-depth studies of the annual flowering rhythms of plants has been conducted, while the research related to the daily flowering rhythms of plants is seldom reported due to limited experimental material. The difference of daily flowering time between L.acutangula Roxb. and L.cylindrica Roem. is nearly 12 hours, which provides a satisfactory experimental material for the study of daily flowering rhythm of plants. In order to understand the genetic mechanism of this phenomenon, we have successfully provided a high-density genetic map, established interspecific introgression lines and constructed the genomic BAC libraries for sponge gourd. Meanwhile, the major QTL locus of daily flowering time of sponge gourd, QFT1, has been located within 0.32 cM of the No. 1 linkage group using near-isogenic lines. Base on that, we are about to clone the QFT1 gene by constructing a larger mapping population, and verify gene function through transgenic complementary experiments, over-expression experiments and gene-editing experiments. Furthermore, by means of gene structure analysis, expression pattern analysis and metabolic pathway analysis of QFT1 gene, we can explore the mechanism of how QFT1 can govern flowering time. This research is supposed to reveal the molecular mechanism of different daily flowering times between L.acutangula Roxb. and L.cylindrica Roem., and establish a reference model to regulate plant daily flowering times. Meanwhile, we can form the basis of eliminating the difference in flowering phase and utilizing interspecific heterosis in sponge gourd.