TITLE

Rapid cytological diploidization in newly formed allopolyploids of the wheat (Aegilops-Triticum) group

AUTHOR(S)
Ozkan, Hakan; Feldman, Moshe
PUB. DATE
November 2009
SOURCE
Genome;Nov2009, Vol. 52 Issue 11, p926
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Recent studies in the genera Aegilops and Triticum showed that allopolyploid formation triggers rapid genetic and epigenetic changes that lead to cytological and genetic diploidization. To better understand the consequences of cytological diploidization, chromosome pairing and seed fertility were studied in S1, S2, and S3 generations of 18 newly formed allopolyploids at different ploidy levels. Results showed that bivalent pairing at first meiotic metaphase was enhanced and seed fertility was improved during each successive generation. A positive linear relationship was found between increased bivalent pairing, improved fertility, and elimination of low-copy noncoding DNA sequences. These findings support the conclusion that rapid elimination of low-copy noncoding DNA sequences from one genome of a newly formed allopolyploid, different sequences from different genomes, is an efficient way to quickly augment the divergence between homoeologous chromosomes and thus bring about cytological diploidization. This facilitates the rapid establishment of the raw allopolyploids as successful, competitive species in nature.
ACCESSION #
48566825

 

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