Aluminium (Al3+) tolerance is second only to drought tolerance for its importance as an agronomic trait in many parts of the world. In wheat (Triticum aestivum L.), Al3+ tolerance is largely conditioned by a single gene, TaALMT1, but given the diverse origins of tolerant genotypes, it is possible that other chromosomes may harbour genes that confer Al3+ tolerance. The large genetic diversity present in synthetic hexaploid wheat (SHW) prompted the objective in this study, which was to evaluate SHW as a source of novel genetic loci linked to Al3+ tolerance. We evaluated 300 SHW accessions using the haematoxylin staining method, and a genome-wide association analysis (GWAS) using 6575 markers generated from traditional diversity-arrays and genotyping-by-sequencing genotyping platforms and from TaALMT1 gene specific simple sequence repeat polymorphisms. The GWAS detected a set of 24 loci located to chromosomes 1B, 1D, 2A, 2B, 4A, 4D, 5A, 5B, 6A, 6D and 7A that showed statistically significant association with Al3+ tolerance. We leveraged the available high-quality annotation data of the wheat genome to identify candidate genes localised to within 1.6 Kb of the identified markers. Besides markers for TaALMT1, MATE and NRAMP, identified markers were located close to known transcription factors (C2H2 zinc finger protein) and novel candidate genes that encode ABC transporter-like protein, glutathione synthetase, Blue copper protein and expansin proteins. In summary, our results showed that Al3+ tolerance is present in SHW but is genetically complex and appeared to involve interactions between the major TaALMT1 gene and other gene loci.

中文翻译：

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合成六倍体小麦作为铝耐受性新遗传位点的来源

铝 (Al3+) 耐受性在世界许多地区作为农艺性状的重要性仅次于耐旱性。在小麦 (Triticum aestivum L.) 中，Al3+ 耐受性主要受单个基因 TaALMT1 的影响，但鉴于耐受基因型的不同起源，其他染色体可能含有赋予 Al3+ 耐受性的基因。合成六倍体小麦 (SHW) 中存在的大量遗传多样性促使本研究的目标是评估 SHW 作为与 Al3+ 耐受性相关的新型遗传位点的来源。我们使用苏木精染色方法评估了 300 个 SHW 种质，以及使用 6575 个标记的全基因组关联分析 (GWAS)，这些标记来自传统的多样性阵列和基因分型测序基因分型平台以及来自 TaALMT1 基因特定的简单序列重复多态性。GWAS 检测到一组位于染色体 1B、1D、2A、2B、4A、4D、5A、5B、6A、6D 和 7A 的 24 个基因座，这些基因座显示出与 Al3+ 耐受性的统计学显着关联。我们利用小麦基因组的可用高质量注释数据来识别定位在已识别标记的 1.6 Kb 内的候选基因。除了 TaALMT1、MATE 和 NRAMP 的标记外，已鉴定的标记位于已知转录因子（C2H2 锌指蛋白）和编码 ABC 转运蛋白样蛋白、谷胱甘肽合成酶、蓝铜蛋白和扩展蛋白的新候选基因附近。总之，