基于Super-GBS技术的高粱籽粒酿造相关性状QTL定位

QTL Mapping of Grain Traits Related to Brewing in Sorghum Based on Super-GBS Technology

为探究酒用高粱籽粒酿造性状的遗传基础,本研究利用超级基因分型技术(Supper-GBS)技术对BTx623×红缨子的205个家系的重组自交系(RIL)群体开展基因分型,构建了包含1910个单核苷酸多态性标记(SNP),标记平均间距为0.47 cM的连锁图谱。结合两年4个环境的表型数据,利用完备区间作图法(ICIM)对籽粒总淀粉含量、支链淀粉含量、单宁含量、硬度和颜色等5个酿造性状进行了数量性状位点(QTL)定位。结果表明,在高粱的1~9号染色体上检测到9、7、11、5和3个QTL分别与总淀粉含量、支链淀粉含量、单宁含量、籽粒硬度和籽粒颜色相关,一共涉及到35个不同的QTL,其中15个QTL与前人定位结果一致。在多个性状和环境中检测到3个重要遗传区段,分别位于1号染色体(66.30~71.55 Mb)、4号染色体(54.00~62.3 Mb)以及6号染色体(54.59~57.57 Mb),其中包括已知的Tan1和Y1基因,以及6个与淀粉和类黄酮合成途径相关的候选基因,如编码β-淀粉酶、黄烷酮3-羟化酶和bHLH转录因子等。本研究结果为酿造性状相关基因的进一步克隆奠定了基础,也为利用标记辅助育种加快酒用高粱的新品种选育提供了理论依据。

In order to explore the genetic basis of grain brewing traits of liquor-making sorghum,in this study,205 recombinant inbred lines(BTx623×HYZ)were genotyped using super genotyping based on sequencing(Super GBS)technology,and a genetic map including 1910 single nucleotide polymorphism(SNP)with a marker interval of 0.47 cM were constructed.Based on the phenotype data in four environments and inclusive composite interval mapping(ICIM)method,9,7,11,5 and 3 quantitative trait locus(QTLs)related to total starch content,amylopectin content,tannin content,grain hardness and grain color respectively were detected on chromosome 1 to 9.Totally,35 unique QTLs were identified,of which 15 were consistent with the previous studies.Three important genetic regions on chromosome 1(66.30-71.55 Mb),chromosome 4(54.00-62.3 Mb)and chromosome 6(54.59-57.57 Mb)were detected in multiple traits and environments.Among which including Tan1 and Y1 genes,as well as 6 candidate genes involving in starch and flavonoid biosynthesis pathway,such as β-amylase,flavanone 3-hydroxylase and bHLH transcription factors.Our results not only lay the foundation for further cloning genes related to brewing traits,but also provide a basis for accelerating the breeding of new varieties for liquor-sorghum using marker-assisted breeding.