Visualization of the Brassica self-incompatibility S-locus on identified oilseed rape chromosomes

Seventy years after Karpechenko [15] first reported the accurate chromosome number of oilseed rape (Brassica napus L., 2n=38), we have developed a qua ntitative chromosome map of rape using computer imaging technology. The cap acity to identify individual rape chromosomes will facilitate a wide range of genetic studies. Here we demonstrate the use of imaging methods in combi nation with fluorescence in situ hybridization to localize, on identified c hromosomes, the single copy S-locus glycoprotein and S-locus-related genes involved in the self-incompatibility system of Brassica. These techniques h ave a broader application in plant genome research involving the mapping of single-copy genes and markers, irrespective of the plant species.