Stadlmeier Melanie, Hartl Lorenz, Mohler Volker
Bavarian State Research Center for Agriculture, Institute for Crop Science and Plant Breeding, Freising, Germany.
TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.
Front Plant Sci. 2018 Dec 6;9:1825. doi: 10.3389/fpls.2018.01825. eCollection 2018.
Multiparent advanced generation intercross (MAGIC) populations were recently developed to allow the high-resolution mapping of quantitative traits. We present a genetic linkage map of an elite but highly diverse eight-founder MAGIC population in common wheat ( L.). Our MAGIC population is composed of 394 F recombinant inbred lines lacking significant signatures of population structure. The linkage map included 5435 SNP markers distributed over 2804 loci and spanning 5230 cM. The analysis of population parameters, including genetic structure, kinship, founder probabilities, and linkage disequilibrium and congruency to other maps indicated appropriate construction of both the population and the genetic map. It was shown that eight-founder MAGIC populations exhibit a greater number of loci and higher recombination rates, especially in the pericentromeric regions, compared to four-founder MAGIC, and biparental populations. In addition, our greatly simplified eight-parental MAGIC mating design with an additional eight-way intercross step was found to be equivalent to a MAGIC design with all 210 possible four-way crosses regarding the levels of missing founder assignments and the number of recombination events. Furthermore, the MAGIC population captured 71.7% of the allelic diversity available in the German wheat breeding gene pool. As a proof of principle, we demonstrated the application of the resource for quantitative trait loci mapping analyzing seedling resistance to powdery mildew. As wheat is a crop with many breeding objectives, this resource will allow scientists and breeders to carry out genetic studies for a wide range of breeder-relevant parameters in a single genetic background and reveal possible interactions between traits of economic importance.
多亲本高级世代杂交（MAGIC）群体最近被开发出来，用于对数量性状进行高分辨率定位。我们展示了一个由八个优良但高度多样化的亲本构建的普通小麦（L.）MAGIC群体的遗传连锁图谱。我们的MAGIC群体由394个F重组自交系组成，没有明显的群体结构特征。该连锁图谱包含5435个单核苷酸多态性（SNP）标记，分布在2804个位点上，跨度为5230厘摩（cM）。对群体参数的分析，包括遗传结构、亲缘关系、亲本概率、连锁不平衡以及与其他图谱的一致性，表明该群体和遗传图谱构建得当。结果表明，与由四个亲本构建的MAGIC群体以及双亲群体相比，由八个亲本构建的MAGIC群体具有更多的位点和更高的重组率，尤其是在着丝粒周围区域。此外，我们大大简化的八亲本MAGIC交配设计，增加了一个八向杂交步骤，发现在缺失亲本分配水平和重组事件数量方面，等同于一个包含所有210种可能的四向杂交的MAGIC设计。此外，该MAGIC群体捕获了德国小麦育种基因库中71.7%的等位基因多样性。作为原理验证，我们展示了该资源在分析白粉病幼苗抗性的数量性状位点定位中的应用。由于小麦是一种具有众多育种目标的作物，该资源将使科学家和育种者能够在单一遗传背景下对广泛的与育种相关的参数进行遗传研究，并揭示具有经济重要性的性状之间可能的相互作用。
