Aegilops tauschii, commonly known as Tausch's goatgrass or rough-spike hard grass, is a wild grass species native to temperate Asia and the Caucasus region. Crucially, this wild diploid species is the D-genome progenitor of bread wheat (Triticum aestivum). Approximately 8,000 years ago in the Fertile Crescent, a spontaneous hybridization event occurred between wild A. tauschii and cultivated tetraploid wheat (Triticum dicoccoides). This natural cross gave rise to hexaploid bread wheat. Thus, this wild progenitor species provided the essential D-genome, contributing vital genetic diversity and evolutionary traits that were fundamental to the development and genetic improvement of modern, high-yielding bread wheat cultivars.