Ancient hybridizations among the ancestral genomes of bread wheat

作者：Marcussen, Thomas; Sandve, Simen R.; Heier, Lise; Spannagl, Manuel; Pfeifer, Matthias; Jakobsen, Kjetill S.; Wulff, Brande B. H.; Steuernagel, Burkhard; Mayer, Klaus F. X.; Olsen, Odd-Arne; Rogers, Jane; Dolezel, Jaroslav; Pozniak, Curtis; Eversole, Kellye; Feuillet, Catherine; Gill, Bikram; Friebe, Bernd; Lukaszewski, Adam J.; Sourdille, Pierre; Endo, Takashi R.; Kubalakova, Marie; Cihalikova, Jarmila; Dubska, Zdenka; Vrana, Jan; Sperkova, Romana; Simkova, Hana; Febrer, Melanie; Clissold, Leah

来源：Science, 2014, 345(6194): 1250092.

DOI：10.1126/science.1250092

• AEGILOPS-TAUSCHII
• DRAFT GENOME
• A-GENOME
• EVOLUTION
• TRITICUM
• DOMESTICATION
• ALIGNMENT
• PACKAGE
• GENES

The allohexaploid bread wheat genome consists of three closely related subgenomes (A, B, and D), but a clear understanding of their phylogenetic history has been lacking. We used genome assemblies of bread wheat and five diploid relatives to analyze genome-wide samples of gene trees, as well as to estimate evolutionary relatedness and divergence times. We show that the A and B genomes diverged from a common ancestor similar to 7 million years ago and that these genomes gave rise to the D genome through homoploid hybrid speciation 1 to 2 million years later. Our findings imply that the present-day bread wheat genome is a product of multiple rounds of hybrid speciation (homoploid and polyploid) and lay the foundation for a new framework for understanding the wheat genome as a multilevel phylogenetic mosaic.

• 出版日期2014-7-18