Wheat (Triticum aestivium L.) is an important crop globally which has a complex genome. To identify the parents with useful agronomic characteristics that could be used in the various breeding programs, it is very important to understand the genetic diversity among global wheat genotypes. Also, understanding the genetic diversity is useful in breeding studies such as marker-assisted selection (MAS), genome-wide association studies (GWAS), and genomic selection. To understand the genetic diversity in wheat, a set of 103 spring wheat genotypes which represented five different continents were used. These genotypes were genotyped using 36,720 genotyping-by-sequencing derived SNPs (GBS-SNPs) which were well distributed across wheat chromosomes. The tested 103-wheat genotypes contained three different subpopulations based on population structure, principle coordinate, and kinship analyses. A significant variation was found within and among the subpopulations based on the AMOVA. Subpopulation 1 was found to be the more diverse subpopulation based on the different allelic patterns (Na, Ne, I, h, and uh). No high linkage disequilibrium was found between the 36,720 SNPs. However, based on the genomic level, D genome was found to have the highest LD compared with the two other genomes A and B. The ratio between the number of significant LD/number of non-significant LD suggested that chromosomes 2D, 5A, and 7B are the highest LD chromosomes in their genomes with a value of 0.08, 0.07, and 0.05, respectively. Based on the LD decay, the D genome was found to be the lowest genome with the highest number of haplotype blocks on chromosome 2D. The recent study concluded that the 103-spring wheat genotypes and their GBS-SNP markers are very appropriate for GWAS studies and QTL-mapping. The core collection comprises three different subpopulations. Genotypes in subpopulation 1 are the most diverse genotypes and could be used in future breeding programs if they have desired traits. The distribution of LD hotspots across the genome was investigated which provides useful information on the genomic regions that includes interesting genes.

中文翻译：

---

利用遗传多样性，种群结构和连锁不平衡对春小麦核心种质进行分子遗传分析。

小麦（Triticum aestivium L.）是全球重要的农作物，具有复杂的基因组。为了确定具有可用于各种育种计划的有用农艺学特征的亲本，了解全球小麦基因型之间的遗传多样性非常重要。同样，了解遗传多样性在育种研究中很有用，例如标记辅助选择（MAS），全基因组关联研究（GWAS）和基因组选择。为了了解小麦的遗传多样性，使用了代表五个不同大陆的103种春小麦基因型。这些基因型是使用36,720个通过测序进行基因分型的SNP（GBS-SNP）进行基因分型的，这些SNP在小麦染色体中分布良好。根据种群结构，经过测试的103种小麦基因型包含三个不同的亚群，原理协调和亲属关系分析。在基于AMOVA的亚群内和亚群之间发现了显着差异。基于不同的等位基因模式（Na，Ne，I，h和uh），发现亚群1是更多样化的亚群。在36,720个SNP之间未发现高连锁不平衡。但是，根据基因组水平，发现D基因组的LD与其他两个基因组A和B相比具有最高的LD。有效LD数目/非有效LD数目之间的比率表明，染色体2D，5A和2D染色体之间存在显着差异。 7B是其基因组中最高的LD染色体，其值分别为0.08、0.07和0.05。基于LD衰变，发现D基因组是2D染色体上具有最低单倍型模块数目的最低基因组。最近的研究得出的结论是，103春小麦基因型及其GBS-SNP标记非常适合GWAS研究和QTL定位。核心集合包括三个不同的子群体。亚种群1中的基因型是最多样化的基因型，如果它们具有所需的性状，则可用于将来的育种程序。研究了LD热点在整个基因组中的分布，这提供了包括有趣基因在内的基因组区域的有用信息。