Topic 3: Neo-evolution

The synthesis of neo-polyploids (AB x D for wheat) over a few generations makes it possible to identify in vivo the genomic reprogramming following (post-) polyploidy at the structural level (translocation-type rearrangements) and functional (non-additivity of the expression of parental genes). Synthetic polyploids allow (1) the identification of the specific evolutionary mechanisms (at the scales of gene organization, regulation and function) acting in polyploids in comparison to their diploid progenitors and (2) the use of this knowledge in pre-breeding programs by through crosses with modern cultivars to introduce unique agronomic traits that are lacking in the cultivated gene pool and thus producing material with potentially novel agronomic properties.

Evolutionary model of the modern bread wheat genome from three progenitors A, B and D. Illustration of the hexaploid bread wheat paleohistory from Ancestor A, (green), Ancestor B (purple) and Ancestor D (brown) within the grasses and more generally flowering plants (angiosperms). Subgenomes are illustrated in different colors so that hybridization events are highlighted with mixed color on the evolutionary tree. Synthetics (nascent polyploids) illustrated in dashed lines can be compared to modern diploid, tetraploid and hexaploid wheat to investigate post-polyploidy genomic reprogramming processes.

Main reference from the group:
Pont C, Leroy T, Seidel M, Tondelli A, Goué N, Lang D, Bustos-Korts D, Balfourier F, Molnar-Lang M, Lage J, Kilian B, Özkan Hakan, Waite D, Dyer S, WHEALBI consortium, IWGSC Russell J, Keller B, Van Eeuwijk F, Spannagl M, Mayer KFX, Waugh R, Stein N, Cattiveli L, Haberer G, Charmet G, Salse J (2019a) Tracing the ancestry of modern bread wheats. NATURE GENETICS. In press