Synthetic hexaploid wheat (SHW), possesses numerous genes for drought that can help breeding for drought-tolerant wheat varieties. We evaluated 10 root traits at seedling stage in 111 F₉ recombinant inbred lines derived from a F₂ population of a SHW line (SHW-L1) and a common wheat line, under normal (NC) and polyethylene glycol-simulated drought stress conditions (DC). We mapped quantitative trait loci (QTLs) for root traits using an enriched high-density genetic map containing 120370 single nucleotide polymorphisms (SNPs), 733 diversity arrays technology markers (DArT) and 119 simple sequence repeats (SSRs). With four replicates per treatment, we identified 19 QTLs for root traits under NC and DC, and 12 of them could be consistently detected with three or four replicates. Two novel QTLs for root fresh weight and root diameter under NC explained 9 and 15.7% of the phenotypic variation respectively, and six novel QTLs for root fresh weight, the ratio of root water loss, total root surface area, number of root tips, and number of root forks under DC explained 8.5–14% of the phenotypic variation. Here seven of eight novel QTLs could be consistently detected with more than three replicates. Results provide essential information for fine-mapping QTLs related to drought tolerance that will facilitate breeding drought-tolerant wheat cultivars.

合成六倍体小麦（SHW）具有许多干旱基因，可以帮助育种耐旱小麦品种。我们评估了来自F _2的111个F ₉重组自交系的苗期10个根系性状在正常（NC）和聚乙二醇模拟的干旱胁迫条件（DC）下，SHW系（SHW-L1）和普通小麦系的种群数。我们使用丰富的高密度遗传图谱（包括120370个单核苷酸多态性（SNP），733个多样性阵列技术标记（DArT）和119个简单序列重复（SSR）），为根部性状绘制了数量性状基因座（QTL）。每个处理重复四次，我们确定了NC和DC下19个根性状的QTL，其中三个或四个重复可以一致地检测到其中的12个。两个新的根鲜重和根直径的QTL分别解释了表型变异的9和15.7％，以及六个新的根鲜重，根失水率，总根表面积，根尖数和根长的QTL。 DC下的根叉数说明8。表型变异的5–14％。在这里，八个以上的新QTL中有七个可以重复检测三个以上。结果为与耐旱性相关的精细定位QTL提供了重要信息，这将有助于育种耐旱小麦品种。