Abstract

Most elite wheat varieties cannot be crossed with related species thereby restricting greatly the germplasm that can be used for alien introgression in breeding programs. Inhibition to crossability is controlled genetically and a number of QTL have been identified to date, including SKr, a strong QTL affecting crossability between wheat and rye located at the distal end of chromosome 5BS. In this study, we used a recombinant SSD population originating from a cross between the poorly crossable cultivar Courtot and the crossable line MP98 to characterize the major dominant effect of SKr and map the gene at the distal end of the chromosome near the 5B homoeologous GSP locus. Colinearity with barley and rice was used to saturate the SKr region with new markers and establish orthologous relationships with a 52 kb region on rice chromosome 12. In total, five markers were mapped within a genetic interval of 0.3 cM and 400 kb of BAC contigs were established on both sides of the gene to lay the foundation for map-based cloning of SKr. Two SSR markers completely linked to SKr were used to evaluate a collection of crossable wheat progenies originating from primary triticale breeding programs. The results confirm the major effect of SKr on crossability and the usefulness of the two markers for the efficient introgression of crossability in elite wheat varieties.

Authors

Alfares W, Bouguennec A, Balfourier F, Gay G, Bergès H, Vautrin S, Sourdille P, Bernard M, Feuillet C.

Genetics. 2009 Aug 3.