Wheat was already an important crop when history was first recorded and so accurate information on the exact time and place of its origin is not available. The distribution of the wild wheats and grasses, believed to be the progenitors of the cultivated wheats, supports the belief that wheat originated in southeastern Asia. Some species were cultivated in Greece, Persia, Turkey, and Egypt in prehistoric times while the cultivation of other species may be of more recent origin. In India, evidences from Mohen-Jo-Daro excavations, indicate that wheat was cultivated there more than 5000 years ago.

The modern origin of wheat is of interest for it is a classical example of how closely related species may be combined in nature into a polyploid series. The species of Triticum genus to which the cultivated wheat belongs and their close relatives may be divided into diploid, tetraploid and hexaploid groups, with chromosome number 2n=14, 28 and 42 respectively. The tetraploid group has originated from two diploid species as indicated by the combination of genomic formulae. The hexaploid species originate by the addition of third genome to a tetraploid specie. The 21 chromosomes of the hexaploid wheat have been assigned into seven homeologous groups, each homeologous group containing a partially homologous chromosome from each of the A, B, and D genomes.