Adhikari, L.; Cavalet-Giorsa, E.; Abrouk, M.; Koo, D.-H.; Correia de Lemos, S.; Lux, T.; Haberer, G.; Portnoy, V.; Salhi, A.; Gao, X.; Miko, P.; Molnar, I.; Rodde, N.; Raupp, J.; Özkan, H.; Spannagl, M.; Kamal, N.; Distelfeld, A.; Poland, J.; Krattinger, S.

Wheat, the most widely cultivated crop globally, includes multiple species with varying ploidy levels. Globally cultivated species such as pasta and bread wheat belong to the Emmer lineage. In contrast, the Timopheevii lineage is of negligible agricultural significance, yet it harbours genetic diversity of potential value for wheat improvement. Here, we present genomic resources for the Timopheevii wheat lineage. Our analyses uncovered extensive homoeologous exchange and genome instability in zhukovsky's wheat, the hexaploid representative of the Timopheevii lineage. Population genomic analyses reveal a mosaic-like haplotype composition of domesticated tetraploid timopheev's wheat, suggesting it was once cultivated across a broader geographic range. This is further supported by the discovery of 'fossil' haplotype segments in bread wheat landraces, likely derived from now-extinct domesticated timopheev's wheat populations. By examining the Timopheevii lineage, we provide new insights into the evolutionary dynamics of wheat, discovering previously underexplored and potentially useful genetic diversity for wheat improvement.