Concluding remarks and future perspectives
The state-of-the-art genomic resources enabled surveys of genetic diversity in many cereal crops and its wild relatives at the ultimate resolution probing variation at millions of nucleotide positions. Using barley as an example, we demonstrated that with the arrival of more detailed and dense genomic datasets the increasingly complex and reticulate models of domestication history emerged. A similar trend is observed in some other cereal crops [15,16 ]. Genome studies provided compelling evidence that hybridization and introgression played a primary role in the cereal domestication and further adaptation. A highly admixed ancestral population(s)seemed to be a progenitor of modern barley domesticates. In rice, japonica subspecies contributed to the domestication of indica through introgression [15]. The maize landraces from Mexico comprised introgressions from conspecific wild relative Z. mays ssp. mexicana, which putatively led to the adaptation of maize to the highland environments [66,67]. In emmer wheat (Triticum turgidum), phylogenetic evidence suggested reticulate domestication history [68].
