Abstract: In order to precisely recognize and karyotype Brassica napus L. chromosomes, C0t-1 DNA was extracted from its genomic DNA, labeled with biotin-11-dUTP and in situ hybridized. The hybridized locations were detected by Cy3-conjugated streptavidin. Specific fluorescence in situ hybridization (FISH) signal bands were detected on all individual chromosome pairs. Each chromosome pair showed specific banding patterns. The B. napus karyotype has been constructed, for the first time, on the basis of both C0t-1 DNA FISH banding patterns and chromosome morphology.

Key words: Brassica napus, C0t-1 DNA, chromosome banding, fluorescence in situ hybridization (FISH), karyotyping.