John Innes Centre, Norwich Research Park, Norwich, UK.
Department of Plant Pathology and Wheat Genetics Resource Center, Kansas State University, Manhattan, KS, USA.
Nat Biotechnol. 2022 Mar;40(3):422-431. doi: 10.1038/s41587-021-01058-4. Epub 2021 Nov 1.
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.
节节麦是普通小麦 D 亚基因组的二倍体野生祖先，是提高小麦产量和环境适应性的遗传多样性库。本研究对 242 份节节麦材料进行了测序，并与小麦 D 亚基因组进行了比较，以鉴定基因组多样性。研究发现，来自现代格鲁吉亚的一种罕见节节麦谱系在导致现代面包小麦形成的独立杂交过程中对小麦 D 亚基因组产生了影响。通过基于 k-mer 的关联作图，研究鉴定到了与疾病和害虫抗性相关的候选基因的离散基因组区域，并通过转基因和广泛杂交将其功能转移到小麦中，包括生成了一个包含不同节节麦基因组的六倍体文库。在六倍体背景下，利用节节麦祖先二倍体基因组的遗传多样性可以快速发现性状并进行功能遗传验证，这有利于小麦的培育。
