Leptosphaeria maculans is the major pathogen of canola (oilseed rape, Brassica napus) worldwide. In Australia, the use of azole fungicides has contributed to the 50-fold increase in canola production in the last 25 years. However, extensive application of fungicides sets the stage for the selection of fungal populations with resistance. A high-throughput in planta assay was developed to allow s...

The fungus Leptosphaeria maculans (Phoma or blackleg disease) causes lesions on leaf, stem and crown tissue of oilseed rape (Brassica napus). It is similar to many other necrotrophic fungi that rely on plant cell death for growth and reproduction. Recent published evidence supports the theory that some, if not all, necrotrophic bacteria and fungi stimulate apoptosis as a prerequisite for infect...

Modern agriculture favours the selection and spread of novel plant diseases. Furthermore, crop genetic resistance against pathogens is often rendered ineffective within a few years of its commercial deployment. Leptosphaeria maculans, the cause of phoma stem canker of oilseed rape, develops gene-for-gene interactions with its host plant, and has a high evolutionary potential to render ineffecti...

All crop species are current or ancient polyploids. Following whole genome duplication, structural and functional modifications result in differential gene content or regulation in the duplicated regions, which can play a fundamental role in the diversification of genes underlying complex traits. We have investigated this issue in Brassica napus, a species with a highly duplicated genome, with ...

Root rot symptoms caused by Leptosphaeria maculans were first reported in Australian canola crops in 2001 but little is known about their importance and prevalence. In a survey of over 100 commercial canola crops in southern NSW, all paddocks had plants with root rot symptoms in 2004, whilst 86% of paddocks did in 2003. Across the two seasons surveyed, there was a strong relationship (r = 0.63)...

Canadian isolates of Leptosphaeria maculans, the causal agent of blackleg of crucifers, were examined for genetic relatedness by the random amplified polymorphic DNA assay. DNA polymorphisms amplified with random decamer primers were used to distinguish three groups of isolates. Group 1 contained all isolates of the virulent pathotype, group 2 contained isolates of the avirulent pathotype from ...