Agropyron cristatum genome provides a new insight for wheat improvement with wild relatives

Exploring novel genetic variation for target traits is crucial for advancing wheat breeding and genetic improvement. Since 1990, we have been transferring genes from Agropyron cristatum, a promising wild relative genetic resource featuring robust spike morphology and stress tolerance, into common wheat by distant hybridization. To efficiently harness A. cristatum genes, we de novo assembled a 25.62-Gb high-quality genome of an autotetraploid accession Z559 with 28 chromosomes, and uncovered its specific genome features and an extensive repertoire of genes associated with yield and resistance to abiotic and biotic stresses. We systematically characterized A. cristatum genome introgressions by resequencing 431 wheat-A. cristatum derivatives and cloned the gene AcGNS1, which functions in the regulation of grain number per spike in wheat. Subsequently, we developed an optimized genome-selection model for wheat-A. cristatum breeding derivatives, enabling the rapid selection of new potential varieties. These findings demonstrate a genomic breeding strategy for leveraging novel genetic resources of wild relatives and advancing wheat improvement.