A Genomic Approach to Assess Weediness and Evolutionary History of Aegilops cylindrica

Aegilops cylindrica (jointed goatgrass), a species which resulted from the hybridization of Ae. tauschii and Ae. markgrafii, is an important weed in wheat production. Aegilops cylindrica has low genetic diversity, the same center of origin and a common progenitor with hexaploid wheat (Triticum aestivum L.). A phylogenetic study using partial sequences from four nuclear genes indicated that hexaploid wheat and Ae. cylindrica are are close in age. These results suggest that the domestication of hexaploid wheat might have favored the origin and establishment of Ae. cylindrica as a species. A genomic comparison between Ae. cylindrica and its parental species found the greatest number of nucleotide differences among the species in genes associated to early flowering, biotic and abiotic stress response and host defense. These genes might be related to the competitive ability and weediness behavior of Ae. cylindrica.