qFT-D3-2，一个棉花开花期相关QTL的精细定位与候选基因鉴定

早熟性是棉花品种培育的重要目标之一。开花期是棉花早熟性的重要标志，对棉花开花期相关基因的定位研究是进行早熟性状分子改良的必要途径。在前期研究中，本实验室利用陆地棉早熟品种中棉所36和晚熟品系G2005杂交构建了一个包含137个家系的重组自交系群体，通过RAD简化测序技术构建了一张高密度遗传图谱，在D3染色体上检测到了一个在4个年份中稳定表达的开花期QTL位点qFT-D3-2，说明该区段包含与棉花开花期相关的基因。因此本研究旨在根据目标区段构建近等基因系群体，对qFT-D3-2位点进行精细定位和候选基因鉴定；利用候选基因结合355份不同熟性陆地棉品种进行棉花熟性相关性状的关联分析，最终鉴定出目标候选基因，同时对候选基因进行遗传进化分析，为解析棉花早熟性状形成的分子机理和早熟棉花品种的分子改良奠定基础。

Earliness is a major goal of cotton breeding. Flowering time is an important early-maturing trait and the research about genetic mapping of cotton flowering time related genes is a necessary way to improve the early-maturing cotton molecular breeding. In the previous study, a population of 137 recombinant inbred lines (RILs) was developed from a cross between early-maturing Gossypium. hirsutum. cv CCRI36 and late-maturing G. hirsutum. acc G2005 and a high-density genetic map was constructed by RAD sequencing technology. A QTL qFT-D3-2 related with flowering time was detected on D3 chromosome in four years, which indicated that there is a gene related with flowering time located on this target chromosome fragment. Therefore, this study will mainly focus on constructing the near-isogenic line (NIL) of target chromosome fragment to fine mapping and identify the candidate genes. And the candidate genes were detected by candidate gene correlation analysis using 355 upland cotton varieties with different maturity, and analyzing the genetic evolution of candidate genes. This research lays the foundation for analyzing the molecular mechanism of early-maturing trait of cotton and improving the molecular breeding of early maturity cotton.