Allopolyploidy accelerates genome evolution in
wheat in two ways: 1) allopolyploidization triggers rapid genome alterations (revolutionary changes) through the instantaneous generation of a variety of cardinal
genetic and
epigenetic changes, and 2) the
allopolyploid condition facilitates sporadic genomic changes during the life of the species (evolutionary changes) that are not attainable at the
diploid level. The revolutionary alterations, occurring during the formation of the
allopolyploid and leading to rapid
cytological and
genetic diploidization, facilitate the successful establishment of the newly formed
allopolyploid in nature. On the other
hand, the evolutionary changes, occurring during the life of the
allopolyploids, increase the intra-specific
genetic diversity, and consequently, increased fitness, adaptability and competitiveness. These phenomena, emphasizing the dynamic plasticity of the
allopolyploid wheat genome with regards to both structure and function, are described and discussed in this review.
