title: Perspectives on the utilization of Aegilops species containing the U genome in wheat breeding: a review
abstract: The genus <i>Aegilops</i> L. is the closest wild relative of wheat (<i>Triticum</i> L.), which contributed two of the three genomes to cultivated wheat. The genus <i>Aegilops</i> comprises 23 species differing in ploidy level and genome composition; diploid species possess the C, D, M, N, S, and U genome types, whereas various genome combinations are identified in tetraploid and hexaploid forms. The U genome is present in diploid <i>Ae. umbellulata</i> and eight polyploid species [<i>Ae. triunci
journal: Frontiers in Plant Science