大豆长童期性状是低纬度地区栽培大豆中控制生育期和产量最重要的性状。本研究将在申请者前期生育期基因功能基因组方面的良好研究基础上，结合新一代全基因组测序技术，图位克隆大豆经典长童期基因J并鉴定基因功能，解析J基因与已克隆的生育期基因E1、E2、E3、E4、CO和FT之间的调控作用关系，阐明阐明J基因调控大豆短日照开花的分子机理，为在国际上率先开展在生育期基因型精细鉴定基础上，研究产量相关基因功能基因组学奠定理论基础；同时通过对已有大豆品种资源生育期基因型鉴定，筛选出适宜的大豆资源，为大豆分子育种提供新材料和新途径。

Soybean long juvenile (LJ) trait not only controls flowering time and maturity but also soybean yield under the low latitude environment. Understanding the molecular mechanism underlying LJ trait regulation is critical for soybean molecular breeding under the low latitude environment. Therefore, in this study, we will identify and characterize the classical LJ trait controlling gene J by combining map-based cloning and next generation resequencing. The genetically regulative relationships of J with known maturity genes, E1, E2, E3, E4, CO and FT will be genetically determined using these maturity gene isolines and transgenic lines. After this study, we will be able to understand the molecular mechanism of photoperiod regulated flowering and maturity under the short-day conditions and facilitate the study of soybean yield more accurately. The gene-specific markers of mutation allele for maturity gene will add the value for molecular breeding.