Origin, domestication, and diversity of the climate resilient Ethiopian cereal teff

Abstract Teff ( Eragrostis tef ) is a climate-resilient cereal and staple crop in the Horn of Africa, cultivated by millions of smallholder farmers. Despite its cultural and nutritional significance, teff has limited genomic tools, constraining progress in yield improvement and trait optimization. Here, we assembled and resequenced the Teff Association Panel (TAP), a diverse set of 265 landraces and cultivars, to investigate the domestication history, genetic diversity, and agronomic traits of teff. Phylogenetic and population genetic analyses confirm Eragrostis pilosa as the direct progenitor of teff, with domestication likely occurring in the Tigray region of Ethiopia. We generated a high-quality reference genome for E. pilosa and found extensive chromosomal collinearity and minimal gene loss compared to teff, with teff-specific genes enriched in functions related to domestication traits. We identified signatures of selection across the teff genome and used genome-wide association studies (GWAS) to map loci associated with seed color and panicle architecture. Integrated GWAS, expression, metabolic, and comparative genomic analyses pinpoint a major seed color locus containing orthologs of the TT7 cytochrome P450 gene involved in flavonoid hydroxylation and the TT2 MYB transcription factor regulating proanthocyanidin biosynthesis. For panicle architecture, we identified a strong association near a teff ortholog of Dense and Erect Panicle 1 (DEP1), a key regulator of inflorescence structure in rice and sorghum. This suggests convergent selection on shared genetic pathways controlling panicle morphology across cereals. Our findings confirm the evolutionary origin of teff, identify key domestication loci, and highlight untapped genetic diversity among Ethiopian breeding lines. These genomic resources provide a foundation for accelerating teff improvement through molecular breeding and genome editing to enhance yield, resilience, and nutrition.