棉花是重要的经济作物，提高棉花产量是当前全世界亟待解决的问题。子指是棉花产量性状的重要组成部分，子指形成机制的研究能为棉花产量的提升提供理论支持和基因资源，但目前相关分子研究甚少。本项目组前期通过图位克隆获得了棉花子指主效QTL的候选基因GhSAPA07，并通过关联分析确定该基因内含子区域变异是子指表型变异的主要原因。本项目拟在此基础上，利用转基因棉花材料，结合转录组分析、亚细胞定位、细胞学观察、蛋白互作分析等技术，阐明GhSAPA07在棉花子指形成中的分子功能；利用全长转录组测序技术研究GhSAPA07转录产物及内含子区域非编码RNA等的变化，并利用含内含子区域系列片段驱动报告基因的遗传转化和活性检测，解析GhSAPA07内含子变异调控子指的分子机理。本研究结果不仅对阐明棉花子指形成的分子机制和内含子的生物学功能研究具有重要科学意义，也为棉花产量提高的分子育种奠定基础。

Cotton is the world’s leading economical crop. Currently, improving the yield of cotton is an urgent issue to be solved by the global cotton industry. Seed index is a significant component of cotton yield traits. Research on seed index would provide theoretical support and gene resources to the increase of cotton production, but little is known about the molecular mechanism of cotton seed index. In our previous study, we identified a candidate gene GhSAPA07 for the seed index QTL of upland cotton by map-based cloning, and detected that the variation in the intron region of GhSAPA07 is the major functional variation. In the present study, a combination of transcriptome analysis, subcellular localization analysis, cytological observation, and interacting proteins detection approaches will be used on transgenic cotton lines to illuminate the molecular mechanism of GhSAPA07 in seed index control; Full-length transcriptome sequencing will be used to identify the transcript and non-coding RNA that might be changed by the variation in GhSAPA07’s intron, genetic transformation and activity detection of reporter gene promoted by series of segment will be carried out to reveal the role of GhSAPA07’s intron. These results will not only be of great scientific significance on understanding the molecular mechanism of cotton seed index and the biological functions of intron, but will also establish foundation for cotton molecular breeding on high-yield varieties.