XVI International Botanical Congess
Fluorescent in situ hybridization and molecular methods were used to investigate the large-scale organization of the sugar beet (Beta vulgaris) genome. Major repeat classes were physically mapped and incorporated into a plant chromosome model.Centromeric and intercalary heterochromatin is largely composed of satellite DNA. Microsatellites show dispersion with site-specific amplification or exclusion and weak interspersion along chromosomes. Retrotransposons are clustered (LINEs), uniformely distributed along chromosomes with depletion at centromeres or rRNA genes (Ty1-copia retrotransposons) or amplified in many centromeres (Ty3-gypsy retrotransposons). FISH enabled the investigation of wild beet introgressions in sugar beet.T.S. acknowledges financial support of the BMBF (BioFuture grant 11860 BFB238).