Common wheat | |
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Ears of common wheat | |
Scientific classification | |
Kingdom: | Plantae |
(unranked): | Angiosperms |
(unranked): | Monocots |
(unranked): | Commelinids |
Order: | Poales |
Family: | Poaceae |
Subfamily: | Pooideae |
Tribe: | Triticeae |
Genus: | Triticum |
Species: | T. aestivum |
Binomial name | |
Triticum aestivum L. |
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Synonyms | |
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Common wheat (Triticum aestivum), also known as bread wheat, is a cultivated wheat species. About 95% of the wheat produced is common wheat, which is the most widely grown of all crops, and the cereal with the highest monetary yield.
Numerous forms of wheat have evolved under human selection. This diversity has led to confusion in the naming of wheats, with names based on both genetic and morphological characteristics. For more information, see the taxonomy of wheat.
Bread wheat is an allohexaploid (an allopolyploid with six sets of chromosomes: two sets from each of three different species). Of the six sets of chromosomes, two come from Triticum urartu (einkorn wheat) and two from Aegilops speltoides. This hybridisation created the species Triticum turgidum (durum wheat) 5800–8200 years ago. The last two sets of chromosomes came from wild goat-grass Aegilops tauschii 2300–4300 years ago.
Free-threshing wheat is closely related to spelt. As with spelt, genes contributed from Aegilops tauschii give bread wheat greater cold hardiness than most wheats, and it is cultivated throughout the world's temperate regions.
Common wheat was first domesticated in Western Asia during the early Holocene, and spread from there to North Africa, Europe and East Asia in the prehistoric period.
Wheat first reached North America with Spanish missions in the 16th century, but North America's role as a major exporter of grain dates from the colonization of the prairies in the 1870s. As grain exports from Russia ceased in the First World War, grain production in Kansas doubled.