先期抽薹是春白菜生产中的重要问题。植株遭遇低温提前通过春化是造成先期抽薹的主要原因。研究白菜春化反应的分子机理对白菜耐先期抽薹的遗传改良具有重要意义。春化路径是植物4条开花控制路径之一。FLC基因是春化路径中的关键基因，在白菜中存在4个拷贝。根据BrFLC1和BrFLC2位点对开花调控的效应差异，我们提出了BrFLC2对BrFLC1存在上位性效应的假设。本项目拟构建白菜BrFLC1和BrFLC2位点的有功能和无功能基因型的近等基因系以及相互组合产生的复合近等基因系，研究相同遗传背景下BrFLC1和BrFLC2位点对控制开花的遗传效应；并且利用转录组测序技术，对BrFLC1和BrFLC2下游开花路径的基因表达和可变剪切进行分析。本研究将对阐明白菜BrFLC1和BrFLC2位点互作对开花调控的分子机理提供重要依据，有助于白菜耐抽薹性的遗传改良。

Premature bolting is one of the important problems in production of Brassica rapa vegetables. The main reason for premature bolting is that plants suffer low temperature leading to achieving of vernalized state before product maturing. Understanding the molecular basis of vernalization response is very important for improvement of bolting resistance in B. rapa crops. Vernalization pathway is one of the four pathways involved in the plant flowering time control. FLC, of which B. rapa has four copies, is the key regulator in vernalization pathway. This project aims to dissect the influence of interactions between BrFLC1 and BrFLC2 on flowering time.Based on their different effect on flowering, we hypothesized that BrFLC2 has epistatic effect on BrFLC1. We propose to use near isogenic lines (NILs) carrying on functional allele or non-functional allele of BrFLC1,or those of BrFLC2, and the combinations of them to analyze their genetic effect on flowering time control; then we will use RNA-seq to analyze the differential expression and alternative splicing patterns of genes which function in downstream of FLC. The results from above studies will contribute to the clarification of molecular mechanisms of interactions between BrFLC1 and BrFLC2 on flowering time, and to be helpful to genetic improvement of bolting resistance in B. rapa vegetables.