On the Origin of the Non-brittle Rachis Trait of Domesticated Einkorn Wheat.

Einkorn and emmer wheat together with barley were among the first cereals domesticated by humans more than 10,000 years ago, long before durum or bread wheat originated. Domesticated einkorn wheat differs from its wild progenitor in basic morphological characters such as the grain dispersal system. This study identified the () and () in einkorn as homologous to barley.

Intraspecific lineage divergence and its association with reproductive trait change during species range expansion in central Eurasian wild wheat Aegilops tauschii Coss. (Poaceae).

Background: How species ranges form in landscapes is a matter of long-standing evolutionary interest. However, little is known about how natural phenotypic variations of ecologically important traits contribute to species range expansion. In this study, we examined the phylogeographic patterns of phenotypic changes in life history (seed production) and phenological (flowering time) traits during the range expansion of Aegilops tauschii Coss.

Genetic basis for spontaneous hybrid genome doubling during allopolyploid speciation of common wheat shown by natural variation analyses of the paternal species.

The complex process of allopolyploid speciation includes various mechanisms ranging from species crosses and hybrid genome doubling to genome alterations and the establishment of new allopolyploids as persisting natural entities. Currently, little is known about the genetic mechanisms that underlie hybrid genome doubling, despite the fact that natural allopolyploid formation is highly dependent on this phenomenon. We examined the genetic basis for the spontaneous genome doubling of triploid F1 hybrids between the direct ancestors of allohexaploid common wheat (Triticum aestivum L.

Evolution and dispersal of emmer wheat (Triticum sp.) from novel haplotypes of Ppd-1 (photoperiod response) genes and their surrounding DNA sequences.

The sequence data from 5' UTR, intronic, coding and 3' UTR regions of Ppd-A1 and Ppd-B1 were investigated for a total of 158 accessions of emmer wheat landraces comprising 19 of wild emmer wheat (Triticum dicoccoides), 45 of hulled emmer wheat (T. dicoccum) and 94 of free-threshing (FT) emmer wheat (T. durum etc.

A novel Au SINE sequence found in a gymnosperm.

Although many SINE families have been identified in the animal kingdom, only a few SINE families have been identified in plants, and their distribution is somewhat limited. The Au SINE (Au) has been found discontinuously in basal angiosperms, monocots, and eudicots. In this study, we examined the presence of the Au in gymnosperms and ferns by PCR using internal primers for Au.

Population structure of wild wheat D-genome progenitor Aegilops tauschii Coss.: implications for intraspecific lineage diversification and evolution of common wheat.

Aegilops tauschii Coss. is the D-genome progenitor of hexaploid wheat. Aegilops tauschii, a wild diploid species, has a wide natural species range in central Eurasia, spreading from Turkey to western China.

Flowering time diversification and dispersal in central Eurasian wild wheat Aegilops tauschii Coss.: genealogical and ecological framework.

Timing of flowering is a reproductive trait that has significant impact on fitness in plants. In contrast to recent advances in understanding the molecular basis of floral transition, few empirical studies have addressed questions concerning population processes of flowering time diversification within species. We analyzed chloroplast DNA genealogical structure of flowering time variation in central Eurasian wild wheat Aegilops tauschii Coss.

Natural variation for fertile triploid F1 hybrid formation in allohexaploid wheat speciation.

The tempo, mode, and geography of allopolyploid speciation are influenced by natural variation in the ability of parental species to express postzygotic reproductive phenotypes that affect hybrid fertility. To shed light on the impact of such natural variations, we used allohexaploid Triticum aestivum wheats' evolution as a model and analyzed the geographic and phylogenetic distributions of Aegilops tauschii (diploid progenitor) accessions involved in the expression of abnormality and fertility in triploid F(1) hybrids with Triticum turgidum (tetraploid progenitor). Artificial-cross experiments and chloroplast-DNA-based evolutionary analyses showed that hybrid-abnormality-causing accessions had limited geographic and phylogenetic distributions, indicative that postzygotic hybridization barriers are underdeveloped between these species.

Pattern and rate of indel evolution inferred from whole chloroplast intergenic regions in sugarcane, maize and rice.

Microstructural changes such as insertions and deletions (=indels) are a major driving force in the evolution of non-coding DNA sequences. To better understand the mechanisms by which indel mutations arise, as well as the molecular evolution of non-coding regions, the number and pattern of indels and nucleotide substitutions were compared in the whole chloroplast genomes. Comparisons were made for a total of over 38 kb non-coding DNA sequences from 126 intergenic regions in two data sets representing species with different divergence times: sugarcane and maize and Oryza sativa var.

A SINE family widely distributed in the plant kingdom and its evolutionary history.

The distribution and evolution of Au SINE in plants were examined. Au SINE is a short interspersed element first identified in Aegilops umbellulata, a close relative of wheat. The Au SINE was previously found in species such as wheat, maize, tobacco, and tomato, but not in rice.

Intra- and interspecific phylogenetic relationships among diploid Triticum-Aegilops species (Poaceae) based on base-pair substitutions, indels, and microsatellites in chloroplast noncoding sequences.

This study analyzes intra- and interspecific variation in chloroplast DNA (cpDNA) in diploid Triticum-Aegilops species. This analysis focused on DNA sequence variation in noncoding regions of cpDNA, which included base-pair substitutions, insertion/deletions (indels, 50 loci pooled), microsatellites (7 loci pooled), and inversions. Nine of 13 Triticum-Aegilops species were successfully identified and genotyped using these data.

Multiple origins of U genome in two UM genome tetraploid Aegilops species, Ae. columnaris and Ae. triaristata, revealed based on the polymorphism of a genome-specific PCR fragment.

To elucidate the evolutionary mode of the formation of species via polyploidization, we conducted phylogenetic analysis of the U genome of the UM genome tetraploid Aegilops species, Ae. columnaris and Ae. triaristata.

Genealogical use of chloroplast DNA variation for intraspecific studies of Aegilops tauschii Coss.

Intraspecific patterns of chloroplast DNA variation was studied in Aegilops tauschii Coss., the D-genome progenitor of bread wheat. Nucleotide sequences of ten chloroplast microsatellite loci were analyzed for 63 accessions that cover the central part of the species distribution.

Chloroplast and nuclear DNA variation in common wheat: insight into the origin and evolution of common wheat.

To understand the origin and evolution of common wheat, chloroplast (ct) and nuclear DNA variations were studied in five hexaploid and three tetraploid wheat subspecies. Based on chloroplast simple sequence repeats at 24 loci, they were classified into two major plastogroups. Plastogroup I consisted of 11 plastotypes, including the major plastotype H10 that occurred at the highest frequency (59%) in common wheat.