BACKGROUND AND AIMS The inflorescence of grass species such as wheat, rice and maize consists of a unique reproductive structure called the spikelet, which is comprised of one, a few, or several florets (individual flowers). When reproductive growth is initiated, the inflorescence meristem differentiates a spikelet meristem as a lateral branch; the spikelet meristem then produces a floret meris...

Hexaploid bread wheat (Triticum aestivum L., genome BBAADD) is generally more salt tolerant than its tetraploid wheat progenitor (Triticum turgidum L.). However, little is known about the physiological basis of this trait or about the relative contributions of allohexaploidization and subsequent evolutionary genetic changes on the trait development. Here, we compared the salt tolerance of a syn...

The Hardness (Ha) locus controls grain hardness in hexaploid wheat (Triticum aestivum) and its relatives (Triticum and Aegilops species) and represents a classical example of a trait whose variation arose from gene loss after polyploidization. In this study, we investigated the molecular basis of the evolutionary events observed at this locus by comparing corresponding sequences of diploid, ter...

In wheat, a lack of genetic diversity between breeding lines has been recognized as a significant block to future yield increases. Species belonging to bread wheat's secondary and tertiary gene pools harbour a much greater level of genetic variability, and are an important source of genes to broaden its genetic base. Introgression of novel genes from progenitors and related species has been wid...

The Glu-1 locus, encoding the high-molecular-weight glutenin protein subunits, controls bread-making quality in hexaploid wheat (Triticum aestivum) and represents a recently evolved region unique to Triticeae genomes. To understand the molecular evolution of this locus region, three orthologous Glu-1 regions from the three subgenomes of a single hexaploid wheat species were sequenced, totaling ...

BACKGROUND Synthetic hexaploid wheats are artificially reconstituted hexaploid wheats that possess high genetic variation which could be utilized for the development of new improved wheat varieties. One such group of synthetic wheats is called the Elite-II set of synthetic wheats that are derived from crossing durum wheat with different Aegilops tauschii wheats. MATERIALS AND METHODS In the c...

To study the D-genome of the wild wheat relative Aegilops tauschii Cosson at the hexaploid level, we developed a synthetic doubled-haploid (DH) hexaploid wheat population, SynDH3. This population was derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from a cross between Triticum turgidum ssp. dicoccon PI377655 and A. tauschii ssp. strangulata AS66 × ssp. tau...

Plant genomes, in particular grass genomes, evolve very rapidly. The closely related A genomes of diploid, tetraploid, and hexaploid wheat are derived from a common ancestor that lived <3 million years ago and represent a good model to study molecular mechanisms involved in such rapid evolution. We have sequenced and compared physical contigs at the Lr10 locus on chromosome 1AS from diploid (21...

Common wheat (Triticum aestivum L.) is one of the most economically important crops in the world, however, gene functional studies in this crop have been lagging mainly due to the complexity of its polyploid genome, which is derived through two rounds of intergeneric hybridization events that led to the presence of six copies for each gene. Elucidating the transcript contribution of each genome...

Gene loss during the formation of hexaploid bread wheat has been repeatedly reported. However, our knowledge on genome-wide analysis of the genes present on a single subgenome (SSG) in bread wheat is still limited. In this study, by analysing the 'Chinese Spring' chromosome arm shotgun sequences together with high-confidence gene models, we detected 433 genes on a SSG. Greater gene loss was obs...