基于全长转录组的GWAS和eQTL解析牡丹心皮数目变异机制

牡丹是我国特有的民族资源植物，集观赏、药用和油用于一体。新品种改良和培育是牡丹产业的关键，利用雄蕊和心皮瓣化特征已培育出了很多新奇品种。心皮数不仅与牡丹花型相关，也与果实（籽粒）产量密切相关，但关于其内在变异机制却知之甚少。本项目旨在完成三代全长转录组测序和部分性状调查的基础上，根据已有600份代表性种质表型和SSR数据，筛选出200份核心种质用于关联分析；利用二代转录组分析，结合表型性状、心皮发育相关基因SNP和基因差异表达信息进行GWAS和表达量eQTL分析，获得与心皮数目相关的候选基因和等位变异；进一步利用表达模式分析和分离群体分析验证候选SNP标记，揭示心皮数目变异机制。本项目兼顾观赏和油用特性，心皮数目变异机制的明晰不仅可以丰富牡丹花型育种和高产育种理论，也可为其分子标记辅助育种奠定基础。油用牡丹发展有利于国家的粮油安全，本项目的研究符合国家战略需求。

Tree peony (Paeonia suffruticosa Andrew) is one of the unique resources of China, with excellent ornamental, medicinal and edible values. Germplasm innovation and breeding are critical for tree peony industry, it has long history in making use of stamen and carpel characteristics for breeding novel cultivars. Carpel is not only important for flower shape but also vital for fruit (seed) yield. However, the intrinsic mechanism on carpel development and number variation of tree peony remains unknown. In this project, based on our primarily obtained full length transcriptome data and phenotype traits of important germplasm, using the obtained 600 representative germplasm and SSR data, we plan to screen 200 core germplasm for association analysis, meantime, carry out GWAS and eQTL analysis based on transcriptome data including carpel related gene expression levels, SNPs and phenotype traits, therefore, identify candidate carpel related genes and allelic variation, and the SNP marker would be testified through expression pattern and segregation group, finally, the mechanism of carpel number variation would be dissected and functional SNPs would be developed and utilized for molecular marker assisted breeding. Our project would combine the ornamental and edible traits, underlying the carpel number variation would not only illuminate knowledge of target breeding new cultivars with novel flower shape or high yield, but also provide theoretical base for MAS breeding. The target of this project fit for the great demands of our country, development of oil tree peony industry will serve for our national strategy on 'Food and Oil safety’.