Soybean (Glycine max (L.) Merrill) is one of the most important crop plants in the world as an important source of protein for both human consumption and livestock fodder. As flowering time contributes to yield, finding new QTLs and further identifying candidate genes associated with various flowering time are fundamental to enhancing soybean yield. In this study, a set of 120 recombinant inbred lines (RILs) which was developed from a cross of two soybean cultivars, Suinong4 (SN4) and ZK168, were genotyped by genotyping-by-sequencing (GBS) approach and phenotyped to expand the cognitive of flowering time by quantitative trait loci (QTL) analysis. Eventually, three stable QTLs related to flowering time which were detected separately located on chromosome 14, 18, and 19 under long-day (LD) conditions. We predicted candidate genes for each QTL and carried out association analyses between the putative causal alleles and flowering time. Moreover, a transient transfection assay was performed and showed that NUCLEAR FACTOR YA 1b (GmNF-YA1b) as a strong candidate for the QTL on chromosome 19 might affect flowering time by suppressing the expression of FLOWERING LOCUS T (GmFT) genes in soybean. QTLs detected in this study would provide fundamental resources for finding candidate genes and clarify the mechanisms of flowering which would be helpful for breeding novel high-yielding soybean cultivars.

大豆（Glycine max (L.) Merrill）是世界上最重要的农作物之一，是人类消费和牲畜饲料的重要蛋白质来源。由于开花时间有助于产量，因此寻找新的QTL并进一步鉴定与不同开花时间相关的候选基因对于提高大豆产量至关重要。在本研究中，通过测序基因分型（GBS）方法对由穗农 4 号（SN4）和 ZK168 两个大豆品种杂交开发的一组 120 个重组自交系（RIL）进行了基因分型和表型分析，以扩展认知能力。通过数量性状基因座（QTL）分析来确定开花时间。最终，在长日照（LD）条件下检测到3个与开花时间相关的稳定QTL，分别位于14、18和19号染色体上。我们预测了每个 QTL 的候选基因，并在假定的因果等位基因和开花时间之间进行了关联分析。此外，进行的瞬时转染测定表明，核因子 YA 1b ( GmNF-YA1b ) 作为 19 号染色体上 QTL 的有力候选者，可能通过抑制大豆中FLOWERING LOCUS T ( GmFT ) 基因的表达来影响开花时间。本研究检测到的QTL将为寻找候选基因、阐明开花机制提供基础资源，有助于选育大豆高产新品种。