Stephen J. Marcroft

Learn More
Resistance of Brassica napus (oilseed rape, canola) conferred by three different major resistance genes has been overcome by changes in virulence of Leptosphaeria maculans populations in France and Australia. In South Australia where B. napus cultivars with major gene resistance derived from Brassica rapa ssp. sylvestris were grown extensively, resistance(More)
Genetic map construction and identification of quantitative trait loci (QTLs) for blackleg resistance were performed for four mapping populations derived from five different canola source cultivars. Three of the populations were generated from crosses between single genotypes from the blackleg-resistant cultivars Caiman, Camberra and AVSapphire and the(More)
The propensity of a fungal pathogen to evolve virulence depends on features of its biology (e.g. mode of reproduction) and of its genome (e.g. amount of repetitive DNA). Populations of Leptosphaeria maculans, a pathogen of Brassica napus (canola), can evolve and overcome disease resistance bred into canola within three years of commercial release of a(More)
Leptosphaeria biglobosa ‘canadensis’ is reported for the first time in Australia. All 88Leptosphaeria isolates cultured fromBrassicajuncea stubble from northern NSW wereL. biglobosa ‘canadensis’ whilst all 55 isolates cultured from Victorian stubble of the sameB. juncea lines wereL. maculans. BothL. biglobosa ‘canadensis’ andL. maculans formed similar sized(More)
Blackleg (Phoma stem canker) caused by Leptosphaeria maculans is the most damaging disease of Brassica napus (canola, rapeseed, colza) worldwide and is controlled by sowing blackleg resistant cultivars and crop management strategies that reduce exposure to inoculum and fungicide application. In experiments in south-eastern Australia, canola cultivars(More)
Fungal diseases are the major constraint on canola (Brassica napus) production in Australia and worldwide. Blackleg (caused by Leptosphaeria maculans) and Sclerotinia stem rot (Sclerotinia sclerotiorum) are the predominant diseases limiting production but, with increased intensification of production, other diseases previously considered of minor importance(More)
The use of fluquinconazole fungicide applied as a seed dressing to canola before sowing was effective at reducing damage caused by the fungus Leptosphaeria maculans, commonly known as blackleg.Whentreated seed was sown under extreme disease severity (canola seed sown into canola stubble), the treated plants had lower levels of internal infection and lower(More)
Juncea canola (Brassica juncea L.) is being developed throughout the worlds canola growing countries as a drought tolerant, shatter resistant and highly blackleg resistant option to canola (Brassica napus L.). Juncea canola was grown commercially in Australia for the first time in 2007. This study determined the incidence and severity of blackleg infection(More)
  • 1