调控番茄开花时间关键基因的克隆与功能分析

The transition from vegetative growth to reproductive growth in tomato depends on flowering time which is an important trait affecting growth period. Dissecting the molecular mechanism of flowering time regulation in tomato has a great value on regulating growth period and improving the adaptability of tomato to the environment. In this study, we constructed recombinant inbred lines (RILs) using a tomato cultivar Solanum lycopersicum 'Moneymaker' and a wild species Solanum pimpinellifolium (PI 365967) as parents and evaluated their flowering time by counting the nodes before the first inflorescence. We plan to identify the major QTLs regulating flowering time in tomato by genome-wide association study (GWAS). We are going to construct the F2 mapping population and develop SNP or InDel markers for fine mapping and cloning of the major candidate genes. We will also verify the biological function of candidate genes by gene editing system and complementary assay to study their roles in regulating flowering time of tomato. Our study will not only improve the regulating network of flowering time in tomato, but also provide the theoretic guidance and available molecular markers for breeding early flowering and harvesting tomatoes.

番茄的开花时间决定了其从营养生长向生殖生长的转变，是影响番茄生育期的一个重要性状。解析调控番茄开花时间的分子机理对调节生育期，提高番茄对环境的适应性有着重要意义。本研究利用栽培番茄品种“Moneymaker”和野生醋栗番茄（PI 365967）为亲本构建了重组自交系群体，对其始花节位进行了系统评价。本项目计划利用全基因组关联分析鉴定调控番茄开花时间的重要QTLs, 并通过构建F2代定位群体，在主效QTL区间内开发SNP或InDel标记，精细定位和克隆候选主效基因。同时通过基因编辑系统及互补实验对候选基因的功能进行验证，从而解析其在调控番茄开花时间中的作用。本研究不仅能够完善番茄开花时间的调控网络，也将为选育早花早熟的番茄品种提供理论依据和可用的分子标记。

番茄的开花时间决定了其从营养生长向生殖生长的转变，是影响番茄生育期的一个重要性状。本研究利用栽培番茄品种“Moneymaker”和野生醋栗番茄（PI 365967）为亲本构建了重组自交系群体，对其长短日照下的始花节位分别进行了系统评价。通过全基因组关联分析及图位克隆等方法，我们定位到了一个只在短日照条件下调控开花的基因FLOWERING LOCUS T-LIKE 1 (FTL1)。FTL1编码一个拟南芥中FLOWERING LOCUS T (FT)的同源蛋白,其在短日照下特异表达，并通过激活SINGLE FLOWER TRUSS (SFT)的表达来促进番茄开花。FTL1在栽培番茄中发生突变导致栽培番茄在短日照下开花变晚。进一步研究表明，FTL1与SELF PRUNING 5G (SP5G)在番茄驯化过程中被人工选择，使番茄由短日照植物变为日中性植物。本研究不仅解析了栽培番茄开花时间对日照长度不敏感的分子机理，完善了番茄开花时间的调控网络，也为选育早花早熟的番茄品种提供了理论依据和可用的分子标记。