Starch content is an important trait in barley. To evaluate the genetic diversity and identify molecular markers of starch content in barley, 40 cultivated barley genotypes collected from different regions, including genotypes whose starch content is at either the high or low end of the spectrum (15), were used in this study. All the genotypes were re-sequenced by the double-digest-restriction associated DNA sequencing method, and a total of 299,103 single-nucleotide polymorphism (SNP) markers were obtained. The genotypes were divided into four sub-populations based on FASTSTRUCTURE, principal component analysis and neighbour-joining tree analysis. All four sub-populations had a high linkage disequilibrium, especially group 3, whose members were recently bred for malting in the Jiangsu coastal area. The starch content of the barley lines was evaluated during three growing seasons (2014–2017), and the average values of starch content across the three growing seasons at the low and high ends were 51.5 and 55.0%, respectively. The starch content was affected by population structure, the barley in group 2 had a low starch content, while the barley in group 4 had a high starch content. Twenty-six SNP markers were identified as being significantly associated with starch content (P ⩽ 0.001) based on the average values across the three growing seasons using the mixed linear model method. These SNP markers were located on chromosomes 1H and 4H, and were considered loci of qSC1-1 and qSC4-1, respectively. The major identified QTLs for starch content are helpful for further research on carbohydrates and for barley breeding.

中文翻译：

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基于散装样本的全基因组关联研究鉴定大麦（Hordeum vulgare L.）中淀粉含量的分子标记

淀粉含量是大麦的一个重要特性。为了评估大麦的遗传多样性和鉴定淀粉含量的分子标记，本研究使用了从不同地区收集的 40 种栽培大麦基因型，包括淀粉含量处于光谱高端或低端的基因型 (15)。所有基因型均采用双酶切限制相关DNA测序法重新测序，共获得299,103个单核苷酸多态性（SNP）标记。基于FASTSTRUCTURE、主成分分析和邻接树分析将基因型分为四个亚群。所有四个亚群都存在高度连锁不平衡，特别是第3组，其成员最近在江苏沿海地区培育麦芽。在三个生长季节（2014-2017年）评估大麦系的淀粉含量，低端和高端三个生长季节的淀粉含量平均值分别为51.5和55.0%。淀粉含量受种群结构影响，第2组大麦淀粉含量低，而第4组大麦淀粉含量高。26 个 SNP 标记被确定为与淀粉含量显着相关（磷⩽ 0.001）基于三个生长季节的平均值，使用混合线性模型方法。这些 SNP 标记位于染色体 1H 和 4H，被认为是qSC1-1和qSC4-1， 分别。主要鉴定的淀粉含量QTL有助于进一步研究碳水化合物和大麦育种。