全基因组关联定位籼稻种质资源外观和加工品质QTL

以400份籼稻变异丰富的种质资源材料在2个环境下考察外观与加工品质性状表型,利用404k高密度SNP基因型进行全基因组关联分析,挖掘影响外观与加工品质性状的重要位点。结果表明,粒形和籼米的外观和加工品质密切相关,垩白性状降低稻米的精米率和整精米率,除粒形外,籼稻的外观和加工品质明显受到环境影响。全基因组关联分析共鉴定到39个QTL,其中17个为新位点,6个新位点(q MRR9、q GL2、q GL10、q GW1、q GLWR1和q GLWR2.1)在2个环境下均被检测到,暗示这6个位点在水稻外观与加工品质上可能是不依赖于环境稳定表达的QTL。此外,21个控制稻米外观品质的位点很可能具一因多效。结合前人研究结果,我们推论q SW5、GSE5和GS3在籼稻外观和加工品质性状上扮演着关键性角色。研究结果为克隆新的外观与加工品质基因,以及通过分子手段加速培育优质高产籼稻新品种提供了指导信息。

Genome-wide Association Study of Grain Appearance and Milling Quality in a Worldwide Collection of Indica Rice Germplasm

Appearance and milling quality are two crucial properties of rice affecting their market acceptability. Understanding the genetic basis of rice grain quality could improve the efficiency of breeding for high quality. Here we carried out genome-wide association analysis using the 404K SNP genotype and data of grain appearance and milling quality for a diverse panel of 400 indica accessions selected from 3K Rice Genome Project collected in two environments. These were closely correlation between grain shape and quality (appearance and milling) of indica rice. The chalk trait reduced milled rice rate and high milled rice rate. In addition to grain shape, the phenotype value of appearance and milling quality traits was obviously affected by environments. Total of 39 QTL were detected which was significantly associated with grain appearance and milling quality in two environments and 17 of them were new QTL. Six new QTL (qMRR9, qGL2, qGL10, qGW1, qGLWR1, and qGLWR2.1) with minor or small effect were considered as stably expressed QTL because they were simultaneously identified in two environments. In addition, we found 21 QTL probably having multiple-effect in appearance and milling quality of indica rice. Combined with the results of previous studies, we concluded that qSW5, GSE5 and GS3 play important role in affecting appearance and milling quality. This research provides valuable information for cloning QTL controlling appearance and milling quality and breeding rice with high yield and good quality by molecular techniques.