Wheats: Origins and Development

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Basic Species Information

Wheat is one of the world’s most widely grown crops today. Together with its typical companion cereal and barley, wheat was the staple cereal crop of several early civilizations extending from the Indus, to Mesopotamia, to ancient Egypt, and throughout the Mediterranean. However, the term, wheat, is to some degree a misnomer, as it is not a single crop species but a complex of several related crop species that belong to the genus Triticum (i.e., Triticum spp.). The various species within this genus derive from hybridizations and multiple domestications, including the hybridization of wheat and the closely related goat-faced grasses (Aegilops spp.), and from post-domestication evolutionary advances, such as the evolution of free-threshing spikelets.

The first major spectrum of variation in the wheats is at the ploidy level (i.e., variation in the number of sets of chromosomes). Figure 1 illustrates the approximate maximal extent of crops ...