Higgins R H, Thurber C S, Assaranurak I, Brown P J
Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801 Energy Biosciences Institute, University of Illinois, Urbana, Illinois 61801.
Energy Biosciences Institute, University of Illinois, Urbana, Illinois 61801.
G3 (Bethesda). 2014 Sep 18;4(9):1593-602. doi: 10.1534/g3.114.013318.
Sorghum varieties suitable for grain production at temperate latitudes show dwarfism and photoperiod insensitivity, both of which are controlled by a small number of loci with large effects. We studied the genetic control of plant height and flowering time in five sorghum families (A-E), each derived from a cross between a tropical line and a partially isogenic line carrying introgressions derived from a common, temperate-adapted donor. A total of 724 F2:3 lines were phenotyped in temperate and tropical environments for plant height and flowering time and scored at 9139 SNPs using genotyping-by-sequencing. Biparental mapping was compared with multiparental mapping in different subsets of families (AB, ABC, ABCD, and ABCDE) using both a GWAS approach, which fit each QTL as a single effect across all families, and using a joint linkage approach, which fit QTL effects as nested within families. GWAS using all families (ABCDE) performed best at the cloned Dw3 locus, whereas joint linkage using all families performed best at the cloned Ma1 locus. Both multiparental approaches yielded apparently synthetic associations due to genetic heterogeneity and were highly dependent on the subset of families used. Comparison of all mapping approaches suggests that a GA2-oxidase underlies Dw1, and that a mir172a gene underlies a Dw1-linked flowering time QTL.
适合在温带地区进行籽粒生产的高粱品种表现出矮化和光周期不敏感的特性，这两种特性均由少数具有较大效应的基因座控制。我们研究了五个高粱家系（A - E）中株高和开花时间的遗传控制，每个家系都源自一个热带品系与一个部分同基因系的杂交，该部分同基因系携带了来自一个常见的温带适应供体的渐渗片段。总共724个F2:3株系在温带和热带环境中对株高和开花时间进行了表型分析，并使用测序基因分型技术在9139个单核苷酸多态性（SNP）位点上进行了评分。使用全基因组关联研究（GWAS）方法（将每个数量性状基因座（QTL）作为所有家系中的单一效应进行拟合）和联合连锁方法（将QTL效应拟合为在家系内嵌套），在不同的家系子集（AB、ABC、ABCD和ABCDE）中比较双亲图谱与多亲图谱。使用所有家系（ABCDE）的GWAS在已克隆的Dw3基因座上表现最佳，而使用所有家系的联合连锁在已克隆的Ma1基因座上表现最佳。由于遗传异质性，两种多亲方法均产生了明显的综合关联，并且高度依赖于所使用的家系子集。所有图谱绘制方法的比较表明，一种GA2 - 氧化酶是Dw1的基础，并且一个mir172a基因是与Dw1连锁的开花时间QTL的基础。
