A pangenome of tetraploid wheat reveals the genetic architecture underlying domestication and genomic diversity for breeding

Researchers have assembled a high-quality pangenome of tetraploid wheat, identifying key genetic markers that drive crop performance. Tetraploid wheat, a crucial ancestor to common bread wheat, contains two subgenomes and acts as a significant reservoir of untapped genetic traits. This study provides a graph-based map covering all ten known subspecies, offering a clear view of the evolutionary history and structural variations that occurred during domestication.

The team analyzed 736 accessions to build a detailed atlas of genetic variation, linking these traits to 32 specific agronomic characteristics. By examining the genetic architecture of wild, domesticated, and free-threshing tetraploid wheat, scientists identified critical gene families and structural variations—specifically insertions, deletions, and inversions—that influence grain size, spikelet number, and stress resistance.

A highlight of the work is the discovery of the HAT14-B gene, which directly affects spikelet numbers and grain size. By testing this elite allele in field trials, the researchers confirmed its role in increasing yield, providing a new target for modern breeding programs. These findings bypass the limitations of using a single reference genome, as the graph-based approach captures complex variation across multiple varieties.

This genomic resource provides a platform for future wheat improvement. With the global demand for food security rising, the ability to access and use these specific genetic variants is a significant step toward developing varieties that adapt better to environmental pressures. The research underscores the value of preserving and analyzing ancestral germplasm to inform future agricultural practices.