Variability of Leptosphaeria maculans in Relation to Blackleg of Oilseed Rape

McGee, D. C.; Petrie, Graham

doi:10.1094/phyto-68-625

Cited by 127 publications

(84 citation statements)

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“…In Canada, L. maculans was first identified in Saskatchewan in 1975 (McGee andPetrie 1978), and later in Manitoba, Alberta and British Columbia (Gugel and Petrie 1992). Prior to the 1970s, only L. biglobosa was identified in Canada and blackleg was not a major concern in rapeseed production.…”

Section: Blackleg Disease In Canadamentioning

confidence: 99%

Insights into fighting against blackleg disease of Brassica napus in Canada

Zhang

Fernando

2018

Crop Pasture Sci.

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Abstract. Blackleg disease, caused by the ascomycete fungal pathogen Leptosphaeria maculans, is a devastating disease of canola (Brassica napus) in Australia, Canada and Europe. Although cultural strategies such as crop rotation, fungicide application, and tillage are adopted to control the disease, the most promising disease control strategy is the utilisation of resistant canola varieties. However, field populations of L. maculans display a high evolutionary potential and are able to overcome major resistance genes within a few years, making disease control relying on resistant varieties challenging. In the early 1990s, blackleg resistance gene Rlm3 was introduced into Canadian canola varieties and provided good resistance against the fungal populations until the early 2000s, when moderate to severe blackleg outbreaks were observed in some areas across western Canada. However, the breakdown of Rlm3 resistance was not reported until recently, based on studies on R genes present in Canadian canola varieties and the avirulence allele frequency in L. maculans populations in western Canada. The fact that Rlm3 was overcome by the evolution of fungal populations demands canola breeding programs in Canada to be prepared to develop canola varieties with diversified and efficient R genes. In addition, frequent monitoring of fungal populations can provide up-to-date guidance for proper resistance genes deployment. This literature review provides insights into the outbreaks and management of blackleg disease in Canada.

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Section: Blackleg Disease In Canadamentioning

confidence: 99%

Insights into fighting against blackleg disease of Brassica napus in Canada

Zhang

Fernando

2018

Crop Pasture Sci.

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“…Furthermore, it has been noted that the variety of blackleg isolates found in Australia are the most virulent (Purwantara et al, 2000), with the susceptibility of the crop and the high availability of Australian inoculums creating conditions conducive to infection (McGee and Petrie, 1979). These Australian isolates can cause disease in naturally more resistant…”

Section: Blackleg Diseasementioning

confidence: 99%

Understanding the structure and variation within the genome of the pathogenic ascomycete fungus Leptosphaeria maculans

Zander¹

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The ascomycete fungus Leptosphaeria maculans is a major pathogen of Brassica species, particularly canola (Brassica napus; rapeseed; oil-seed rape), and the primary cause of crop losses of canola in Australia, causing blackleg disease. L. maculans, a filamentous ascomycete, is the causal agent of phoma stem canker, commonly referred to as blackleg.In late stages of infection, it spreads through the stem vasculature causing lesions, leading to poor growth, lodging and eventually plant death. This fungus is found in canola-growing regions worldwide such as Australia, Canada and Europe. Increased production of canola in these regions has led to a rise in the severity of the disease. In Australia alone, L. maculans infection is responsible for an estimated Australian $100 million in crop losses each year, with average losses ranging from 15-48 % and significant efforts are underway to improve resistance to this disease.Understanding the characteristics of L. maculans is vital for developing an effective and sustainable approach to the management of blackleg disease on Brassica species. The completion of the L. maculans genome sequence was a significant development in the study of this fungal pathogen and provides a reference genome to which molecular markers can be physically mapped. This has been highly useful in other plant pathogens with sequenced genomes, such as the wheat pathogen Parastagonospora nodorum and the cereal pathogen Fusarium graminearum. Importantly, a reference genome also allows mapping of whole genome re-sequencing data, which is becoming a high-throughput, costeffective method to study genome-wide diversity, particularly for the relatively small, lower complexity genomes of many fungal species. By re-sequencing the genome of different L. maculans isolates, variations in genome sequence and structure can be elucidated.Advances in genome sequencing technologies have revolutionised plant and fungal genomics. They have made genome sequencing, re-sequencing and Single Nucleotide Polymorphism (SNP) discovery highly accessible, high-throughput and cost-effective. The process of whole genome re-sequencing involves aligning millions of short sequence reads to a reference genome sequence. Once this has been achieved, it is possible to identify genetic variation between individuals, which can be linked to variation in phenotype to provide molecular genetic markers and insights into gene function.Sequence variation can have a major impact on how an organism develops and responds to the environment. III | P a g eThis thesis describes the implementation of several approaches to elucidating the genome structure and variation of a number of L. maculans isolates, including SNPs and presence/absence variations (PAVs).Initially, the re-sequencing of two L. maculans isolates for the identification of 21,814 SNPs was performed. I demonstrated the application of a novel SNP calling method, SGSautoSNP and its robustness and sensitivity in identifying polymorphisms in L.maculans. I described the use of these S...

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“…Agar was placed into the test tubes (10 ml per tube) and sterilized in the autoclave at 120 ºC for 20 minutes. After cooling, fungal mycelium of all tested isolates was placed onto the agar and under the photoperiod of 12 h at 20 o C (McGee & Petrie 1978). Pigment formation was monitored for 4 weeks, based on the changes in colour of the agar.…”

Section: Pigment Formation On a Liquid Czapek Agar Platementioning

confidence: 99%

“…During 2005 and 2006 P. lingam was registered in all production regions of rapeseed in Vojvodina (Mitrović & Marinković, 2007). In the earlier period, populations of fungus L. maculans were divided in two groups based on their pathogenicity and described as aggressive or non-aggressive (McGee & Petrie, 1978;which do not produce sirodesmins. In Australia, epidemic is caused only by the group A, while in Canada and Western Europe, damage is caused by both groups .…”

mentioning

confidence: 99%