Drought is one of the complex abiotic phenomena that limit wheat production. Improving drought tolerance at the seedling stage is very important as it is a critical stage affecting the subsequent growth stages. In this study, a population consisted of 138 diverse spring wheat genotypes was used to identify the most drought tolerant genotypes and genomic regions controlling drought tolerance at the seedling stage. Three morphological traits were scored: seedling length, days to wilting, and leaf wilting. All genotypes had a high genetic variation in all the seedling traits scored in this study. Moreover, high significant phenotypic and genotypic correlations were found among these traits. Heritability estimates for these morphological traits ranged from 0.59 to 0.86. Nine genotypes from different countries were identified as drought-tolerant genotypes. The genome-wide association study (GWAS) was performed on the population using 407 Diversity Arrays Technology (DArT) markers which were distributed across 21 wheat chromosomes. The results of GWAS revealed 104 significant QTL controlling drought tolerance and susceptibility in wheat. A set of 12 markers was found to be associated with more than one trait. Out of the 12 markers, the WPT-2356 was found to be associated with drought susceptibility in all traits scored in this study. The gene annotation analysis revealed that this marker fell within TraesCS7B02G438200 gene model which encodes to UBA-like superfamily protein (a negative drought regulator). Moreover, four significant DArT markers WPT-6668, WPT-8460, WPT-8124, and WPT-4196 found in this study were previously reported with their association with drought tolerance and susceptibly at wheat seedling stage. The nine genotypes can be used as candidate parents to improve drought tolerance in spring wheat. Moreover, promising validated markers can be used for marker-assisted selection to genetically improve drought tolerance through a breeding program.

干旱是限制小麦产量的复杂非生物现象之一。在苗期提高抗旱性非常重要，因为它是影响后续生长期的关键阶段。在这项研究中，由138种不同春小麦基因型组成的种群被用来确定最耐旱的基因型和控制苗期耐旱性的基因组区域。对三个形态特征进行了评分：幼苗长度，萎to天数和叶片萎wil。在这项研究中，所有基因型在所有幼苗性状上都有很高的遗传变异。此外，在这些性状之间发现高度显着的表型和基因型相关性。这些形态性状的遗传力估计范围为0.59至0.86。来自不同国家的9个基因型被确定为耐旱基因型。使用407分集阵列技术（DArT）标记对种群进行了全基因组关联研究（GWAS），该标记分布在21个小麦染色体上。GWAS的结果显示104个重要的QTL控制小麦的耐旱性和敏感性。发现一组12个标记与一个以上的性状相关。在这12个标记中，WPT-2356与本研究中评分的所有性状均与干旱敏感性相关。基因注释分析表明，该标记属于TraesCS7B02G438200基因模型，该模型编码为UBA样超家族蛋白（负干旱调​​节剂）。此外，四个重要的DArT标记WPT-6668，WPT-8460，WPT-8124，该研究中发现的WPT-4196和WPT-4196与耐旱性相关，并且在小麦幼苗期易感。这九种基因型可以用作候选亲本，以提高春小麦的耐旱性。此外，有希望的经过验证的标记物可用于标记物辅助选择，以通过育种程序遗传改良耐旱性。