Expression of morphological and flowering time variation through allopolyploidization: An empirical study with 27 wheat synthetics and their parental Aegilops tauschii accessions

Abstract

It was recently shown that allopolyploidy brings novel epistatic interactions to genes belonging to different genomes. However, systematic studies of the phenotypic relationships between synthetic hexaploid wheats and their parental lines have not been conducted. In this study, 27 synthetic hexaploid wheats were produced by crossing the tetraploid wheat cultivar 'Langdon' with 27 accessions of Aegilops tauschii. Variations in 20 morphological and flowering traits were analysed in both, the synthetic wheat lines and the parental Ae. tauschii accessions. The 20 traits exhibited large variations in the wheat lines. For many of the traits, the degree of variation in the parental accessions was reduced, in the hexaploid derivatives. Principal, component analysis of floret-related traits divided the Ae. tauschii accessions into two subspecies, ssp. tauschii and ssp. strangulata, but this parental pattern of subspecific division was not detectable in the hexaploids. Our results suggest that the 'Langdon' genome may have an alleviating effect on the expression of D-genome-derived variations in derived synthetics. © 2009 Blackwell Verlag GmbH.