Blackleg, caused by the fungus Leptosphaeria maculans, is one of the most devastating diseases of canola (Brassica napus) worldwide. Several sources of partial resistance in the Brassica genomes have been utilized in breeding programs for generating improved cultivars. In addition, a source of complete resistance has been identified in the B genome of Brassica species. However, the relationship between different sources of resistance is not clearly understood. The objective of this study is to identify DNA markers associated with various resistant genes in Brassica genomes. A diverse collection of 129 genotypes and accessions of Brassica species, of which some are known to contain resistance to blackleg, are being screened for this study. Isolates of L. maculans will be used to inoculate seedlings for greenhouse screening while adult plants resistance will be evaluated in a blackleg nursery at the University of Georgia, Griffin. Thirteen RAPD primers known to be linked with the resistance and Brassica microsatellites will be used to profile the entire genome of Brassica species. A combined analysis of disease scores along with DNA marker profiles will identify the genomic regions associated with resistance. The association mapping information may further be useful for canola breeding programs and to study the genetics of Brassica-Leptosphaeria interactions.