DISCRIMINATION AMONG CULTIVARS OF RAPESEED (BRASSICA-NAPUS L) USING DNA POLYMORPHISMS AMPLIFIED FROM ARBITRARY PRIMERS

RAPDs(Randomly Amplified Polymorphic DNAs) were used to discriminate a mong 23 cultivars of oilseed rape (Brassica napus) selected from sever al breeding programs. A set of 100 random sequence 10-mer primers were tested, of which 70 produced bands and 22 showed evidence of polymorp hism. A selection of six primers produced 23 polymorphic bands of betw een 300 to 2200 base pairs in size, sufficient to distinguish between the cultivars. An analysis of seed of five cultivars obtained from fou r different sites showed stability of banding pattern over source of s eed. The analysis was repeated using four different thermocyclers, eac h of which produced the same band pattern. UPGMA cluster analysis indi cates that the relationships among some of the cultivars is closer for those from the same breeding program than for those from different pr ograms. The results of this study show that RAPDs can be used as a met hod of identification for oilseed rape cultivars.