梅花花期性状的全基因组关联分析和遗传机制解析

Prunus mume is an early flowering plant unique to China, and it is a valued asset for landscape use and Chinese culture. Prunus mume is a subtropical species, thus it is not cold-resistant. For now, only a few varieties of Apricot Mei and Meiren Mei can be planted outside in the northern regions of China, and their flowering time is much later than that of other varieties. Therefore, it is of great significance to enrich the flowering time diversity of current varieties for landscape use in China. However, the knowledge of molecular mechanism underlying flowering time in Prunus mume is still limited, which restricts molecular breeding for new varieties. Based on previous re-sequencing data of Prunus mume cultivars, our study aims to first observe the flowering related traits of re-sequenced varieties, re-analyze the sequencing data to identify SNP variants, and perform genome-wide association analysis to detect SNPs and candidate genes significantly associated with flowering time. We will further validate the functional role of candidate genes by examining their expression pattern during flower opening process to screen for key regulatory genes. To sum up, our study will reveal the genetic architecture of flowering time and provide potential markers for molecular breeding in Prunus mume.

梅花是我国特有的早春观花植物，在中国园林及花文化中有着举足轻重的位置。梅花属亚热带树种，抗寒性较差。目前仅有杏梅和美人梅种系品种能在北方地区露地栽植，但其花期远晚于真梅品种。因此，梅花花期改良育种对于丰富品种花期多样性，满足冬春季节园林应用具有重要意义。至今，梅花花期调控分子机制仍缺乏系统研究，严重制约着花期分子育种的开展。本研究基于前期已完梅花栽培品种全基因组重测序工作，拟通过观测花期相关性状，构建花期表型数据库；利用群体遗传突变分析流程鉴定群体基因型；结合表型数据与基因型数据，利用全基因组关联分析鉴定与花期性状显著关联的分子标记和候选基因。最后，结合候选基因在开花过程中的表达模式进一步鉴定关键基因，解析梅花花期遗传机制，为花期改良分子育种提供优异功能标记。

梅花（Prunus mume Sieb.et Zucc.）是我国重要的木本观赏植物，也是我国十大传统名花之一。梅花品种资源丰富，不同品种间花期表型变化大，但花期性状变异的遗传调控机制尚不清楚。本研究以235份梅花种质材料为研究对象，综合多年花期表型观测，利用群体重测序与全基因组关联分析，鉴定了一系列与梅花花期性状紧密关联的分子标记和候选基因。在此基础上，结合梅花早花、晚花品种开花过程的比较转录组分析，进一步筛选了191个参与调控梅花花芽发育与开花时间的关键候选基因，并验证了候选基因表达模式与不同品种开花进程的一致性。本项目初步解析了梅花品种间花期性状遗传机制，确定了控制花芽发育与开花时间的关键基因，为加速梅花花期分子育种与遗传改良提供了理论依据。