Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, Madrid, Spain.
National Plant Genetic Resources Centre, National Institute for Agricultural and Food Research and Technology, Alcalá de Henares, Spain.
BMC Genomics. 2020 Feb 4;21(1):122. doi: 10.1186/s12864-020-6536-x.
One of the main goals of the plant breeding in the twenty-first century is the development of crop cultivars that can maintain current yields in unfavorable environments. Landraces that have been grown under varying local conditions include genetic diversity that will be essential to achieve this objective. The Center of Plant Genetic Resources of the Spanish Institute for Agriculture Research maintains a broad collection of wheat landraces. These accessions, which are locally adapted to diverse eco-climatic conditions, represent highly valuable materials for breeding. However, their efficient use requires an exhaustive genetic characterization. The overall aim of this study was to assess the diversity and population structure of a selected set of 380 Spanish landraces and 52 reference varieties of bread and durum wheat by high-throughput genotyping.
The DArTseq GBS approach generated 10 K SNPs and 40 K high-quality DArT markers, which were located against the currently available bread and durum wheat reference genomes. The markers with known locations were distributed across all chromosomes with relatively well-balanced genome-wide coverage. The genetic analysis showed that the Spanish wheat landraces were clustered in different groups, thus representing genetic pools providing a range of allelic variation. The subspecies had a major impact on the population structure of the durum wheat landraces, with three distinct clusters that corresponded to subsp. durum, turgidum and dicoccon being identified. The population structure of bread wheat landraces was mainly biased by geographic origin.
The results showed broader genetic diversity in the landraces compared to a reference set that included commercial varieties, and higher divergence between the landraces and the reference set in durum wheat than in bread wheat. The analyses revealed genomic regions whose patterns of variation were markedly different in the landraces and reference varieties, indicating loci that have been under selection during crop improvement, which could help to target breeding efforts. The results obtained from this work will provide a basis for future genome-wide association studies.
二十一世纪作物育种的主要目标之一是开发能够在不利环境下保持当前产量的作物品种。在不同的当地条件下种植的地方品种包含了实现这一目标所必需的遗传多样性。西班牙农业研究所植物遗传资源中心保存了广泛的小麦地方品种收藏。这些适应不同生态气候条件的品种是非常有价值的育种材料。然而，要有效利用它们，就需要进行详尽的遗传特征描述。本研究的总体目标是通过高通量基因分型，评估一组 380 份西班牙地方品种和 52 份面包和硬粒小麦参考品种的多样性和群体结构。
DArTseq GBS 方法生成了 10 K SNPs 和 40 K 高质量 DArT 标记，这些标记与现有的面包和硬粒小麦参考基因组相对应。具有已知位置的标记分布在所有染色体上，具有相对平衡的全基因组覆盖度。遗传分析表明，西班牙小麦地方品种聚类在不同的群体中，从而代表了提供一系列等位基因变异的遗传库。亚种对硬粒小麦地方品种的群体结构有重大影响，鉴定出了三个不同的聚类，分别对应于亚种 durum、turgidum 和 dicoccon。面包小麦地方品种的群体结构主要受地理起源的影响。
结果表明，与包括商业品种在内的参考品种相比，地方品种具有更广泛的遗传多样性，硬粒小麦地方品种与参考品种的分化程度高于面包小麦。分析显示，地方品种和参考品种之间存在明显不同的变异模式的基因组区域，表明在作物改良过程中受到选择的位点，这有助于针对育种工作。从这项工作中获得的结果将为未来的全基因组关联研究提供基础。
Zotero 插件
