We examined three different-ploidy wheat species to elucidate the development of aboveground architecture and its domesticated mechanism under environment-controlled field conditions. Architecture parameters including leaf, stem, spike and canopy morphology were measured together with biomass allocation, leaf net photosynthetic rate and instantaneous water use efficiency (WUE(i)). Canopy biomas...

The allohexaploid bread wheat originally derived from three closely related species with A, B and D genome. Although numerous studies were performed to elucidate its origin and phylogeny, no consensus conclusion has reached. In this study, we cloned and sequenced the genes Wcor15-2A, Wcor15-2B and Wcor15-2D in 23 diploid, 10 tetraploid and 106 hexaploid wheat varieties and analyzed their molecu...

Grain shape and size are involved in the main components of the domestication syndrome in cereals. Wheat grain shape has been dramatically altered at each stage of the domestication of tetraploid wheat and through common wheat speciation. To elucidate the evolutionary change of wheat grain shape, principal component (PC) analysis of grain shape-related traits was first conducted using wild and ...

Comparative study of disease resistance genes in crop plants and their relatives provides insight on resistance gene function, evolution and diversity. Here, we studied the allelic diversity of the Lr10 leaf rust resistance gene, a CC-NBS-LRR coding gene originally isolated from hexaploid wheat, in 20 diploid and tetraploid wheat lines. Besides a gene in the tetraploid wheat variety 'Altar' tha...

To study the phylogeny and domestication of tetraploid wheat species, variations in nuclear DNA of the cultivated and wild species were investigated by RFLP analysis. Twenty-two accessions representing 11 species of cultivated tetraploid wheat (Emmer wheat and Timopheevi wheat), 16 accessions of wild Emmer wheat (Triticum dicoccoides Körn.), 14 accessions of wild Timopheevi wheat (T. araraticum...

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 wheat consists of three subgenomes, namely, A, B, and D. These well-characterized ancestral genomes also exist at the diploid and tetraploid levels, thereby rendering wheat as a good model species for studying polyploidization. Here, we performed intra- and inter-species comparative analyses of wheat and its relatives to dissect polymorphism and differentiation of the TaGW2 genes. Our...

Genetic diversity in breeding programs can be impaired by fixation of alleles derived from a limited number of founder lines. This is demonstrated with the use of a solid-stem trait derived from the Portuguese landrace 'S-615' over 70 yrs ago that is widely used to resist the wheat stem sawfly ( Norton, WSS) in North America. The objective of this study was to evaluate haplotype diversity under...

It is widely believed that hexaploid wheat originated via hybridization of hulled tetraploid emmer with Aegilops tauschii (genomes DD) and that the nascent hexaploid was spelt, from which free-threshing wheat evolved by mutations. To reassess the role of spelt in the evolution of Triticum aestivum, 4 disomic substitution lines of Ae. tauschii chromosome 2D in Chinese Spring wheat were developed...