基于QTL-Seq的水稻籽粒蛋白含量性状的QTL定位

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Abstract：Grain protein content （GPC）represents one of the critical factors aecting rice eating quality. It is of great significance for improving this trait through analyzing its geneticregulation mechanism.This study deployed arecombinant inbred line （RIL） population derived from two japonica rice cultivars，Zhengeng 2400 and Jiahe 218，showing significant diffrenceon grain protein content.A quantitative trait loci（QTL）-Seq was used to locate the QTLs controlling grain protein content in rice. QTL mapping and fine mapping was performed usingIci Mapping4.1 software.Through deploying ΔsNP indexanalysis of the F8：9 RIL population，four QTLs on chromosomes 1，2，and 12 were identified.Eight QTLs on chromosomes 1，2，6，7，8，9，and1l in the F9：10 RIL population were detected by the Euclidean distance（ED）method analysis.A major QTL，designated qGPCI ，accounting for 13.20% of the phenotypic variation with a LOD score of 3.91，was consistently detected both in F8：9 and F9：10 RIL.Fine mapping delimited qGPC1 to a 516kb interval between markers 1-3782 and

1-3834.Sequenceanalysis of a reported GPC regulatory gene OsAAP6 revealed no polymorphisms between parents，suggesting the presence of a novel regulatory gene controling GPC.A low-GPC line with superior eating quality from the RIL population was selected as a parental donor for developing the new cultivar strain Zhendao 1818.This advanced line exhibited significantly improved palatability scores to commercial cultivars Wuyunjing 23and Nanjing 5055，along with increased plant height，seed setingrate，and thousand-grain weigh.Collctively，this study lays the foundation for further cloning of grain protein content genes and analyzing genetic regulatory mechanisms，and provides excelent germplasm resources for improving rice eating quality.

Key words： rice;eating quality;grain protein content;QTL mapping

水稻是我国重要的粮食作物之一，随着人民生活水平的提高，人们对优质食味稻米的需求越来越大。（剩余17443字）