果糖作为可溶性糖中影响甜度和口感的主要成分，对番茄果实风味品质的形成具有重要的作用。国内外学者已经挖掘了多个调控番茄果糖含量的QTL，仍缺乏可应用于育种的功能性分子标记。本项目前期以低果糖栽培番茄和高果糖野生醋栗番茄为亲本构建包含201个株系的重组自交系群体。利用全基因组关联分析的方法，在2号染色体上获得了一个调控果实果糖含量的主效QTL Qfru2.3，其表型贡献率达14.71%。本项目拟通过构建定位群体对Qfru2.3进行精细定位，结合定位区间内基因注释信息，对基因的序列多态性和表达模式进行分析，筛选候选基因FRU2.3；通过基因编辑及互补遗传转化验证候选基因的功能，并进一步对主效候选基因FRU2.3的生物学功能和遗传效应进行分析；并在调控果糖含量关键基因FRU2.3上开发功能性分子标记，用于高果糖番茄种质的筛选。本项目将为番茄果实品质改良提供新的解决思路，加快高品质番茄的选育。

As the main component of soluble sugar directly affecting fruit sweetness and taste, fructose plays an important role in tomato fruit flavor quality formation. A number of quantitative trait loci (QTLs), regulating fructose content, have been excavated in tomato fruit at home and abroad. Molecular markers are still in need, which could be applied to molecular breeding. In this project, we constructed recombinant inbred lines with 201 individual lines, by using cultivated tomato Solanum lycopersicum with low fructose content and wild species Solanum pimpinellifolium with high fructose content as parents. A dominant QTL Qfru2.3, regulating fruit fructose content with phenotypic contribution up to 14.71%, was obtained on chromosome 2 in tomato fruit, using genome-wide association study. We intend to fine map Qfru2.3 by constructing targeting population. Through integrating gene annotation information in the QTL and analyzing its gene polymorphism and expression pattern, we aim to screen gene FRU2.3. Gene editing and complementary genetic transformation will be used to verify the functions of candidate gene. The biological function and genetic effects of main candidate gene FRU2.3 will be further analyzed. Meanwhile, functional molecular markers will be developed on key gene FRU2.3 for screening high-fructose tomato germplasm, which regulates fructose content. This project will provide a new solution for tomato fruit quality improvement to accelerate the breeding of high-quality tomato.