基于高密度遗传图谱对高粱穗部性状的QTL定位

QTL Identifying for Panicle Architecture-Related Traits in Sorghum Based on High-Density Genetic Map

利用高密度遗传图谱进行高粱穗部相关性状的QTL分析,为酒用高粱标记辅助育种和重要基因遗传机制解析提供理论依据。以美国籽粒高粱品种BTx623和酱香型白酒用高粱品种红缨子构建的包含205个家系的RIL群体为试验材料,2020-2021年在贵州贵阳、安顺和海南乐东的5个环境下,开展了5个穗型性状(穗长、穗柄长、穗轴节数、一级枝梗数和最长一级枝梗长)的调查。利用高密度连锁图谱,采用完备区间作图法(ICIM)开展QTL定位。在高粱的基因组上一共检测到61个QTL涉及45个不同QTL遗传位点,其中与穗长、穗柄长、穗轴节数、一级枝梗数和最长一级枝梗长相关QTL分别为14、10、8、11和18个。在多个性状或多个环境中被重复检测到的19个重要QTL位点分别位于1(3个)、3(4个)、4(2个)、5(1个)、6(4个)、7(1个)、8(3个)和9(1个)号染色体上,并在其中12个QTL位点置信区间内或附近确定了13个候选基因,它们与控制水稻穗型的基因同源(DEP1、RGN1、OsPID、OsSPL7和WTG1等),为进一步克隆和功能验证这些候选基因提供依据。

The aim of this study was to use a high-density genetic map to identify QTL for panicle architecture-related traits in sorghum,which would enable marker-assisted selection and the exploration of the genetic mechanisms of key genes underlying these traits.205 recombinant inbred lines(RILs)from a cross between BTx623,an American cultivar,and Hongyingzi,a cultivar for brewing liquor,were used to investigate five panicle traits in five environments(Guiyang,Anshun and Ledong)from 2020 to 2021.These traits include panicle length(PL),panicle handle length(PHL),number of cob nodes(NCN),number of primary branches(NPB),and length of the longest primary branch length(LLPB).The inclusive composite interval mapping(ICIM)method was used to identify QTL,enabling the identification of 61 QTL at 45 unique loci.Of these,14、10、8、11 and 18 QTL were related to PL,PHL,NCN,NPB,and LLPB,respectively.Nineteen important QTL were identified across multiple traits or environments and were distributed on chromosome 1(3),3(4),4(2),5(1),6(4),7(1),8(3),and 9(1).In addition,13 orthologous genes for rice panicle architecture were found in or near 12 of the 19 QTL,including DEP1,RGN1,OsPID,OsSPL7 and WTG1.These findings provided a basis for gene cloning and function verification in future.