Abstract
Wheat supplies most staple food in the world. Wheat is characteristic of its polyploidy nature. Polyploidy enables us to establish a complete set of aneuploid series and a number of deletion lines of all chromosomes in common wheat (AABBDD: 6x). Furthermore, because of its crossability with other Triticeae plants, addition lines of wheat with alien genomes and chromosomes as well as alloplasmic lines with all cytoplasms of Aegilops species can be successfully produced and successively maintained. Although huge genome size and polyploidy disturbed, to some extent, molecular research of wheat, recent developments such as mapping of DNA markers, accumulation of comprehensive ESTs, preparation of oligo DNA microarrays and constructions of BAC libraries from common wheat, its ancestral tetraploid and diploids allow us to conduct genomics. These situations clearly indicate that wheat should be used as a model plant to study complex genome systems of polyploids
