Aegilops tauschii, the diploid wild progenitor of the D subgenome of bread wheat, is a reservoir of genetic diversity for improving bread wheat performance and environmental resilience. Here we sequenced 242 Ae. tauschii accessions and compared them to the wheat D subgenome to characterize genomic diversity. We found that a rare lineage of Ae. tauschii geographically restricted to present-day Georgia contributed to the wheat D subgenome in the independent hybridizations that gave rise to modern bread wheat. Through k-mer-based association mapping, we identified discrete genomic regions with candidate genes for disease and pest resistance and demonstrated their functional transfer into wheat by transgenesis and wide crossing, including the generation of a library of hexaploids incorporating diverse Ae. tauschii genomes. Exploiting the genomic diversity of the Ae. tauschii ancestral diploid genome permits rapid trait discovery and functional genetic validation in a hexaploid background amenable to breeding.

节节麦是面包小麦 D 亚基因组的二倍体野生祖细胞，是提高面包小麦性能和环境适应力的遗传多样性库。在这里，我们对 242 Ae 进行了测序。tauschii种质并将它们与小麦 D 亚基因组进行比较以表征基因组多样性。我们发现了一种罕见的Ae 谱系。tauschii在地理上仅限于当今的格鲁吉亚，在产生现代面包小麦的独立杂交中为小麦 D 亚基因组做出了贡献。通过k基于聚体的关联作图，我们确定了具有抗病虫害候选基因的离散基因组区域，并通过转基因和广泛杂交证明了它们在小麦中的功能转移，包括生成包含多种Ae 的六倍体文库。tauschii基因组。利用Ae 的基因组多样性。tauschii祖先二倍体基因组允许在适合育种的六倍体背景中快速发现性状和功能遗传验证。