Fluorescence-based AFLPs occur as the most suitable marker system for oilseed rape cultivar identification

Three different types of molecular markers, RAPD, SSR and fluorescence-based AFLP, were evaluated and compared for their ability to identify oilseed rape cultivars. The direct comparison of RAPD, SSR and AFLP approaches in cultivar identification showed that the AFLP methodology detected polymorphisms more efficiently than either RAPD or SSR methods. For the characterisation of six oilseed rape cultivars, 60 RAPD primers were tested and only eight of them (14%) detected sufficient levels of polymorphism. Five microsatellites out of fifteen tested were polymorphic, but in all loci, except one, only two different alleles were detected. This result indicated the limited degree of polymorphism found in Brassica napus. Each of the six tested AFLP combinations detected polymorphisms, the best combination (M-CAA/E-ACT) had 26% polymorphic peaks from a total of 90 peaks and could distinguish the analysed cultivars and 4 out of 5 core lines of cultivars. The results presented show that florescence-based AFLP is, for the purposes of oilseed rape cultivar fingerprinting, a more suitable approach than either RAPD or SSR.