Wild emmer wheat genome assembly reveals centromere remodeling across all 14 chromosomes

Researchers have produced a near-complete genome assembly of wild emmer wheat (Triticum turgidum ssp. dicoccoides), resolving centromeric regions for all 14 centromeres of this BBAA-genome species. The work, published in Nature Genetics on 22 October 2026, delivers a high-resolution tetraploid wheat reference and documents how centromeres were reshaped as wheat evolved from wild progenitor to cultivated polyploid forms.

Wild emmer wheat is the wild progenitor of cultivated tetraploid and hexaploid wheats, making it a key reference for investigating centromere reorganization during polyploidization and domestication. By closing these gaps across the full 14-chromosome complement, the assembly provides an unusually complete view of centromere structure in a wild wheat genome.

Comparative analyses with cultivated tetraploid and hexaploid wheats revealed extensive variation in centromere-associated sequences and in centromere-proximal structure. Notably, the changes were not uniform across the genome: the analysis uncovered distinct subgenome-associated patterns in the A and B subgenomes, indicating that the two ancestral genomes contributing to wheat evolved their centromeres along different trajectories.

In the A subgenome, the researchers observed positional shifts and sequence turnover of CRW-rich centromere-derived blocks. Figure panels in the study trace the relocation and turnover dynamics of a centromeric CRW block on chromosome 1A across wheat ploidy levels, suggesting that these blocks have moved and been replaced as ploidy increased from diploid ancestors through tetraploid to hexaploid lineages.

The B subgenome told a different story. There, the tandem repeat satellite CentT566 showed reduced abundance overall, but with localized retention or expansion on specific chromosomes. A comparative analysis of CentT566 dynamics across wheat polyploidization, presented in the study, documents this subgenome-specific pattern of satellite loss and persistence.

The study also examined functional centromere organization and centromere-proximal structural variation between wild and cultivated tetraploid wheat, mapping genome-wide distribution, composition and evolutionary dynamics of centromeres in the Zavitan accession of wild emmer wheat. A summary figure consolidates the centromere-associated remodeling patterns observed across wheat lineages.

Together, these findings provide a resource for wheat genomics and a detailed picture of subgenome-associated centromere remodeling during wheat polyploid evolution. Because the assembly resolves all 14 centromeres in a wild progenitor species, it offers a baseline against which centromere changes accompanying domestication and the formation of hexaploid bread wheat can be measured.

Subject of Research: Centromere reorganization in wild emmer wheat revealed by a near-complete genome assembly

Article Title: Near-complete assembly of wild emmer wheat unveils centromere reorganization during polyploid evolution

Article References: Yi, C., Liu, Q., Shen, L., Zhang, J., Zhu, C., Wang, T., Han, F., & Liu, Y. (2026). Near-complete assembly of wild emmer wheat unveils centromere reorganization during polyploid evolution. Nature Genetics. https://doi.org/10.1038/s41588-026-02808-3

Image Credits: AI Generated

DOI: 10.1038/s41588-026-02808-3

Keywords: wild emmer wheat, genome assembly, centromere, polyploidization, subgenome, Triticum turgidum, CentT566 satellite, CRW blocks, tetraploid wheat, hexaploid wheat, structural variation, Nature Genetics