Blackleg caused by Leptosphaeria maculans is one of the important diseases widely affecting canola production worldwide. Effectiveness of three plant defence related genes transferred from pea (Pisum sativum) to canola was tested against blackleg in two experiments. In the first experiment, three transgenes including PR10.1, Chitinase, and DRR206 were transferred from transgenic Wester variety into four commercial cultivars (Apollo, Sentry, OAC Triton, and MillenniUM 03) via backcrossing to examine the effects of different genetic backgrounds on disease response. In the second experiment, to study the effect of gene pyramiding on level of disease resistance, three transgenic Wester lines were crossed. Cotyledon inoculation was performed for indoor disease screening tests of blackleg. DRR206 in Sentry and Chitinase×DRR206 appeared to be the best combinations conferring disease resistance. Overall, DRR206 had the highest impact on disease, probably due to delayed infection development. Promising lines of this research could be utilized in breeding programs and cultivar release projects after field trials.