Advances in understanding the Leptosphaeria maculans-Brassica pathosystem and their impact on disease management

Abstract

Recent advances in genomics have led to a greater understanding of blackleg disease of canola, caused by the fungus Leptosphaeria maculans. Genome sequences are available for several L. maculans isolates and different Brassica species, and several resistance and avirulence genes, which have a ‘gene for gene’ relationship, have been characterised. Although several pairs of complementary resistance and avirulence genes have been sequenced, the molecular basis of their recognition is unknown. Mechanisms responsible for conferring virulence include amino acid substitutions, gene deletion and Repeat Induced Point mutations of avirulence genes. In some cases, a single avirulence gene is recognised..