西瓜果肉质地相关基因精细定位与功能预测

Due to the continuous improvement of modern life and fruit market globalization, the quality requirements for watermelon people and increasing attention as the texture of fruit quality of watermelon and an important component of the evaluation index, directly affects the fruit taste, storage and transport, so by the fruit industry attention. Watermelon fruit flesh is a quantitative trait controlled by multiple genes, which is the result of the interaction of genotype and environment. In this study, 300 different types of watermelon as the research object, carries on the preliminary positioning related to watermelon texture gene by GWAS method, the difference of cultivated watermelon fruit texture significantly and sticky watermelon preparation of F2 populations (>3000 strain), and re sequencing of two parent materials, combined with high-throughput SNP genotyping means to complete the fine mapping of the target gene; at the same time 10 servings of fruit texture of watermelon materials of different developmental stages of the cell structure, chemical composition and transcriptome analysis, through correlation analysis, gene mining and watermelon fruit texture formation and control network; and the key gene function identification. The study aimed to provide the basis for further study on the formation mechanism of watermelon flesh texture and the improvement of watermelon quality.

由于现代生活水平的不断提高和果品市场全球化进程的加快，人们对西瓜的品质要求和关注度不断提高，其中质地作为西瓜果实品质的重要组成部分和评价指标，直接影响果实的口感、贮藏与运输。.西瓜果肉质地是多基因调节的数量性状，其变化是基因型和环境共同作用的结果，受众多基因和代谢网络的共同调控。.本研究以300份不同类型西瓜为研究对象，通过GWAS方法对与西瓜质地相关基因进行初步定位，将果肉质地差异极显著的栽培西瓜和黏籽西瓜配制F2分离群体（>3000株），并对两亲本材料进行重测序，结合高通量SNP基因分型手段完成目标基因的精细定位；同时进行10份果肉质地有代表性的西瓜材料不同发育阶段的细胞组织结构、理化成分和转录组分析，通过相关性分析，挖掘与西瓜果肉质地形成的基因及调控网络；并进行关键基因功能鉴定。为进一步探明西瓜果肉质地形成机理以及改良西瓜品质提供依据。

本研究利用软果肉栽培西瓜品系“W1-1”和硬果肉黏籽西瓜品系“PI186490”开展西瓜中心果肉硬度主效基因精细定位及候选基因分析等研究，以“W1-1”为母本，“PI186490”为父本，构建六世代群体，分析中心果肉硬度遗传规律，通过BSA-seq和构建遗传连锁图谱，定位控制西瓜中心果肉硬度的主效基因。同时测量6份不同果肉质地西瓜品种不同发育时期中心果肉质地参数、细胞壁物质含量、激素含量、细胞大小及排列和基因表达水平，并结合定位结果，鉴定目标区段内候选基因，对候选基因进行克隆，以期为西瓜中心果肉硬度分子标记辅助选择育种和西瓜果肉质地种质改良奠定理论基础，加快育种进程。