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Thinopyrum chromosomes 7el1, 7el2, 7Ee, and 7Ei, homoeologous to group 7 chromosomes of common wheat (Triticum aestivum), were determined to have many useful agronomical traits for wheat improvement. To analyze the genetic relationships among the 4 Thinopyrum 7E chromosomes, the conserved orthologous set markers, genomic in situ hybridization (GISH), and meiotic chromosome pairing were used in this study. The unweighted pair-group method with arithmetical averages (UPGMA) analysis indicated that 7el1, derived from T. ponticum, and 7Ei, derived from T. intermedium, were the most closely related. 7el2, derived from T. ponticum, was relatively distant from the 7el1-7Ei complex. While 7Ee, derived from T. elongatum, was more distantly related to 7el1, 7el2, and 7Ei. This is the first report showing that 7el1 and 7Ei may be similar, which could be explained by the similar chromosome signal distribution revealed by GISH as well as UPGMA analysis revealed by both molecular markers and the highest frequency of meiotic pairing. The newly developed genome-specific molecular markers may be useful for marker-assisted selection of Lr19, Bdv3, and Fhblop. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Bread wheat derives from a grass ancestor structured in seven protochromosomes followed by a paleotetraploidization to reach a 12 chromosomes intermediate and a neohexaploidization (involving subgenomes A, B and D) event that finally shaped the 21 modern chromosomes. Insights into wheat syntenome in sequencing conserved orthologous set ( COS) genes unravelled differences in genomic structure (such as gene conservation and diversity) and genetical landscape (such as recombination pattern) between ancestral as well as recent duplicated blocks. Contrasted evolutionary plasticity is observed where the B subgenome appears more sensitive (i.e. plastic) in contrast to A as dominant (i.e. stable) in response to the neotetraploidization and D subgenome as supra-dominant (i.e. pivotal) in response to the neohexaploidization event. Finally, the wheat syntenome, delivered through a public web interface Plant Synteny Viewer at http://urgi.versailles.inra.fr/synteny-wheat, can be considered as a guide for accelerated dissection of major agronomical traits in wheat. [ABSTRACT FROM AUTHOR]