Klie Maik, Menz Ina, Linde Marcus, Debener Thomas
Department of Molecular Plant Breeding, Institute for Plant Genetics, Leibniz Universitaet Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany.
Kleinwanzlebener Saatzucht AG formerly Rabbethge and Giesecke, Grimsehlstraße 31, 37574, Einbeck, Germany.
Mol Genet Genomics. 2016 Apr;291(2):957-69. doi: 10.1007/s00438-015-1155-y. Epub 2016 Jan 19.
Chrysanthemums are important ornamental plants with abundant phenotypic diversity. Especially in cut-flower breeding, shoot branching is important for the success of new varieties. To assess the genetic regulation of shoot branching and other horticultural important traits, we phenotyped and genotyped two types of chrysanthemum populations: a genotype collection of 86 varieties and a biparental F1-population (MK11/3) of 160 individuals. Using two different statistical approaches, a genome-wide association analysis and a single marker ANOVA, with AFLP marker data and candidate gene markers for shoot branching, we tried to identify markers correlated to the traits of interest. As expected for the outcrossing hexasomic chrysanthemums most of the phenotypic traits showed a continuous variation in both populations. With the candidate gene approach we identified 11 significantly associated marker alleles for all 4 strigolactone pathway genes BRC1, CCD7, CCD8 and MAX2 regulating shoot branching in the genotype collection. In the MK11/3 we detected seven markers for all candidate genes except MAX2 explaining a large proportion of the variation. Using anonymous AFLP markers in the GWA with the 86 genotypes and the single locus analysis with the F1-population we could detect 15 and 17 additional marker-trait associations, respectively. Our analyses indicate a polygenic inheritance of the shoot branching in the chrysanthemum, with a fundamental role of the strigolactone pathway genes BRC1, CCD7, CCD8 and MAX2 and we identified 50 associated markers to all traits under study. These markers could be used in the selection of the parental plants for breeding chrysanthemums to enrich them for positive alleles influencing plant architecture traits.
菊花是具有丰富表型多样性的重要观赏植物。特别是在切花育种中，枝条分枝对新品种的成功培育很重要。为了评估枝条分枝和其他园艺重要性状的遗传调控，我们对两种菊花群体进行了表型和基因分型：一个包含86个品种的基因型收集群体和一个由160个个体组成的双亲F1群体（MK11/3）。我们使用两种不同的统计方法，即全基因组关联分析和单标记方差分析，结合AFLP标记数据和枝条分枝的候选基因标记，试图鉴定与感兴趣性状相关的标记。正如对异交六倍体菊花所预期的那样，大多数表型性状在两个群体中都呈现连续变异。通过候选基因方法，我们在基因型收集群体中为调控枝条分枝的所有4个独脚金内酯途径基因BRC1、CCD7、CCD8和MAX2鉴定出11个显著相关的标记等位基因。在MK11/3群体中，我们除了MAX2外，为所有候选基因检测到7个标记，这些标记解释了很大一部分变异。在86个基因型的全基因组关联分析中使用匿名AFLP标记，以及在F1群体中进行单基因座分析，我们分别检测到另外15个和17个标记-性状关联。我们的分析表明菊花中枝条分枝的多基因遗传，独脚金内酯途径基因BRC1、CCD7、CCD8和MAX2起基本作用，并且我们鉴定出50个与所有研究性状相关的标记。这些标记可用于选择菊花育种的亲本植物，以富集影响植株结构性状的正等位基因。
