Abstract Drought is one of the most important abiotic stresses limiting yield production in cereal crops which deleteriously affects food security worldwide. The study aimed to identify marker-trait associations (MTAs) and putative candidate genes underlying agronomic and seed related traits under post-anthesis drought stress in a set of 183 spring barley gene bank accessions from 23 countries that were genotyped with a 9 K SNP chip. Plants were grown in the field in two consecutive years and post-anthesis drought stress was simulated by spraying 1% KI ten days after anthesis. The treatment caused a significant reduction in total biomass by 10.7 %, in kernel number by 2.5 %, in kernel weight per spike by 21.4 % and in thousand kernel weight (TKW) by 16.7 %, whereby most tolerant accessions were HOR 5970, HOR 6606 and HOR 6560. GWAS analysis of best linear unbiased estimators (BLUEs) revealed 97 significant MTAs associated with kernel number and kernel weight per spike and confirmed prominent regions such as 2H (18.9 cM), 6H (54.8 cM) and 7H (70.5-71.0 cM) for drought response and were co-localized with ten putative candidate genes. Gene annotation indicates that genes for the plant respiratory burst oxidase homologs (rboh) family, the carotenoid cleavage dioxygenase 1 (CCD1) and RNA-binding proteins (RBPs) might be involved in tolerance and stress response mechanisms during post-anthesis drought stress. In conclusion, the study provides essential information about significant MTAs and candidate genes related to drought tolerance which can be further used for marker-assisted selection. More drought tolerant barley accessions may be used as pre-bred material to widen the genetic diversity of cultivated barley and to meet the demands for cultivars in world’s areas which suffer post-anthesis drought stress.

中文翻译：

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全基因组关联图揭示大麦耐旱性的推定候选基因

摘要 干旱是限制谷类作物产量的最重要的非生物胁迫之一，对全球粮食安全产生不利影响。该研究旨在确定花后干旱胁迫下农艺和种子相关性状的标记-性状关联 (MTA) 和推定候选基因，这些基因来自 23 个国家的 183 个春季大麦基因库材料，这些材料用 9 K SNP 芯片进行了基因分型。 . 植物在田间连续种植两年，开花后 10 天通过喷洒 1% KI 模拟开花后干旱胁迫。处理导致总生物量显着减少 10.7%，粒数减少 2.5%，每穗粒重减少 21.4%，千粒重 (TKW) 减少 16.7%，其中最耐受的种质是 HOR 5970，HOR 6606和 HOR 6560。GWAS 对最佳线性无偏估计量 (BLUE) 的分析揭示了 97 个与每个穗粒数和籽粒重量相关的重要 MTA，并确认了干旱的 2H (18.9 cM)、6H (54.8 cM) 和 7H (70.5-71.0 cM) 等突出区域反应并与十个假定的候选基因共定位。基因注释表明植物呼吸爆发氧化酶同源物 (rboh) 家族、类胡萝卜素裂解双加氧酶 1 (CCD1) 和 RNA 结合蛋白 (RBPs) 的基因可能参与开花后干旱胁迫期间的耐受和胁迫反应机制。总之，该研究提供了与耐旱性相关的重要 MTA 和候选基因的基本信息，可进一步用于标记辅助选择。