A set of single nucleotide polymorphism ͑SNP͒ markers has been developed for each of the nine linkage groups of sugar beet. Each set can monitor the polymorphic state at five to six linked marker loci. In each set, the loci selected for marker development are first amplified in a multiplexed reaction. These amplification products are the basis for sequence-specific elongation of primers adjacent to SNP positions. The extension step revealing SNP loci is based on fluorescently labelled nucleotides. In each set, primers developed to reveal SNP alleles differ in length to allow clear peak resolution in capillary electrophoresis. The nine linkage group ͑LG͒ Ϫ specific sets provide information on the polymorphism at a total of 52 SNP marker loci. Using the SNP-based tool, groups of concerned loci have been anchored to three different linkage maps of sugar beet. In a second experiment, sugar beet breeding lines have been fingerprinted. The use of the nine sets of LG-specific markers in sugar beet genetics and breeding is discussed. The information necessary to specify the 52 marker loci, as well as their map location, and all details concerning SNP assays, including allele type and nature of mutation, are reported.
Abbreviations:LG -linkage group; SNP -single nucleotide polymorphism; RFLP -restriction fragment length polymorphism; RAPD -random amplification of polymorphic DNA; AFLP -amplified fragment length polymorphism; CAPS -cleaved amplified polymorphic sequence; SSCP -single strand conformation polymorphism; SSR -simple sequence repeat; STS -sequence tagged site; QTL -quantitative trait locus; nt -nucleotide