植物花开放时间（Flower Opening Time，FOT）由生物钟调控，与植物适应性、繁殖力和生存力密切相关。FOT遗传变异研究对揭示物种进化和提高作物产量具有重要意义。萱草属FOT受生物钟的精确调控，可分为昼夜开放两种类型且无生殖隔离，是研究FOT遗传规律和生物钟调控机制的新模式植物。在已获得萱草群体昼夜FOT遗传规律的基础上，项目采用大数据分析建立FOT遗传模式；对相同遗传背景不同FOT个体的各发育阶段进行转录组测序分析，筛选调控FOT的生物钟关键候选基因，并通过荧光定量验证表达模式；设计光暗周期信号重置试验，分析关键基因的震荡规律，在不同光暗条件下对FOT不同的植株进行mRNA和miRNA转录组测序，联合分析关键基因响应光信号变化的机制；CRISPR/Cas9及免疫共沉淀验证关键基因在萱草中的表达和功能，探索蛋白互作关系，揭示关键基因表达网络，以期实现对植物FOT精准高效调控。

Flower opening time which is closely related to fitness, fertility and viability of plants is regulated by circadian clock. Knowledge about its genetic variation is important to reveal the evolution of species and increase crop yields. Flower opening in Hemerocallis is accurately modulated by circadian clock and is categorized into diurnal and nocturnal opening types. And there is no complete reproductive isolation between the two types. Considering these properties, Hemerocallis would become new model plants to study the genetic rules and circadian clock regulation mechanism of flower opening time. Based on the genetic rules of flower opening time in hybrids between diurnal-opening and nocturnal-opening Hemerocallis, this project attend to establish genetic model of flower opening time with big data analysis. The key candidate clock genes regulating flower opening time are screened through RNA-sequencing with samples from individuals which have the same genetic backgrounds but different flower opening time, and the samples are collected at different development stage. Then expression patterns of these key genes will be verified by fluorescence quantitative PCR. Through light signal resetting experiments, the analysis of the oscillatory expression of key clock genes in different photoperiods are combined with mRNA and miRNA sequencing of individuals which have different flower opening time in different photoperiods to analyze the mechanism of key clock genes responding to the change of environmental light signal. The expression and function of the key genes are verified and the interaction between proteins is explored, thus the gene expression network that accurately regulates flower opening time of Hemerocallis can be revealed. This project is expected to realize precise and efficient regulation of flower opening time in the future, lay a foundation for revealing the adaptive evolution law of plants to the environment, and provide guidance for improving plant survival technology.