ABSTRACT
The origin of the genus Amaranthus was probably in America. This assumption is reasonable considering that 60 species are native to the New World and about 15 to the Old World. In traditional production areas, hand threshing is a strong limitation; On the other hand, mechanized production is essential for increasing area of amaranth production. The total variation available for breeding grain amaranth must be considered to get a clear picture of the potential for genetic improvement. There are at least five levels of the grain amaranth gene pool corresponding to more and more highly selected genetic materials. The grain amaranth species are characterized by compound monoecious inflorescence and pentamerous flowers with circumcessile utricules. The basic units of the inflorescence are dicacial cymes, usually called glomerules, each ordinarily consisting of an initial staminate flower and an indefinite number of pistillate flowers.
