Super-pangenome analyses across 35 accessions of 23 Avena species highlight their complex evolutionary history and extensive genomic diversity

Abstract

Common oat, belonging to the genus Avena with 30 recognized species, is a nutritionally important cereal crop and high-quality forage worldwide. Here, we construct a genus-level super-pangenome of Avena comprising 35 high-quality genomes from 14 cultivated oat accessions and 21 wild species. The fully resolved phylogenomic analysis unveils the origin and evolutionary scenario of Avena species, and the super-pangenome analysis identifies 26.62% and 59.93% specific genes and haplotypes in wild species. We delineate the landscape of structural variations (SVs) and the transcriptome profile based 1,401 RNA-sequencing (RNA-seq) samples from diverse abiotic stress treatments in oat. We highlight the crucial role of SVs in modulating gene expression and shaping adaptation to diverse stresses. Further combining SV-based genome-wide association studies (GWASs), we characterize 13 candidate genes associated with drought resistance such as AsARF7, validated by transgenic oat lines. Our study provides unprecedented genomic resources to facilitate genomic, evolution and molecular breeding research in oat. A genus-level super-pangenome of Avena comprising 35 high-quality genomes from 23 cultivated or wild oat species highlights the evolution of Avena and the landscape of structural variations related to abiotic stress resistance.