Introgressing the Aegilops tauschii genome into wheat as a basis for cereal improvement

An introgression platform for transferring genetic variations of Aegilops tauschii to hexaploid wheat is established based on synthetic octoploid wheat. Combined with newly generated genome resources of A. tauschii, it represents a powerful tool for wheat gene discovery and breeding. Increasing crop production is necessary to feed the world's expanding population, and crop breeders often utilize genetic variations to improve crop yield and quality. However, the narrow diversity of the wheat D genome seriously restricts its selective breeding. A practical solution is to exploit the genomic variations of Aegilops tauschii via introgression. Here, we established a rapid introgression platform for transferring the overall genetic variations of A. tauschii to elite wheats, thereby enriching the wheat germplasm pool. To accelerate the process, we assembled four new reference genomes, resequenced 278 accessions of A. tauschii and constructed the variation landscape of this wheat progenitor species. Genome comparisons highlighted diverse functional genes or novel haplotypes with potential applications in wheat improvement. We constructed the core germplasm of A. tauschii, including 85 accessions covering more than 99% of the species' overall genetic variations. This was crossed with elite wheat cultivars to generate an A. tauschii-wheat synthetic octoploid wheat (A-WSOW) pool. Laboratory and field analysis with two examples of the introgression lines confirmed its great potential for wheat breeding. Our high-quality reference genomes, genomic variation landscape of A. tauschii and the A-WSOW pool provide valuable resources to facilitate gene discovery and breeding in wheat.

Automated summary

An introgression platform was established to transfer genetic variations from Aegilops tauschii to elite wheat, enriching the wheat gene pool. Through resequencing and genome comparisons, diverse functional genes or novel haplotypes in A. tauschii were identified, offering potential applications for wheat improvement.