The Gossypium raimondii genome, a huge leap forward in cotton genomics.

Cotton,in the Gossypium genus,constitutes five tetraploid (2n=4x=52)and 45 diploid(2n=2x=26)species,which are believed to have originated from a common ancestor 5-10 million years ago(MYA).Upland cotton(G.hirsutum,AADD, 2n=4x=52),which is responsible for over 90%of the world’s cotton lint production,is thought to have undergone an allopolyploidization event about 1-2 MYA involving both A and D genome species(Wendel and Albert 1992).The progenitor of G.raimondii(DD,2n=2x=26)is considered the contributor of the D subgenome,while ancestors of G,arboreum(AA, 2n=2x=26) may have contributed the A subgenome to G.