Lange: Rapid Farm-Level Detection of Blackleg Pathotypes - Proof of Concept
Date: March 2013
Term: 1 year
Status: Completed
Researcher(s): Ralph Lange, Xiujie Li, Jian Zhang, Alberta Innovates Technology Futures Vegreville, AB
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: n/a
Project Summary
Researchers developed and tested a proof of concept for a rapid farm-level detection test for blackleg disease as a potential method for predicting resistance or susceptibility to uncharacterized L. maculans isolates present in the field. In the project, researchers developed an assay to test a class of enzymes, the chitinases, to determine if they were associated with either susceptible or resistant reactions to infection by L. maculans. Researchers concluded from the study that it is not practical to use the expression of this enzyme to predict resistance or susceptibility to uncharacterized L. maculans.
Blackleg is a major disease in canola caused by the fungal pathogen Leptosphaeria maculans. Although several cultivars of canola (B. napus) currently have genetic resistance to blackleg, the pathogen has been adapting to the resistance genes. Researchers at Alberta Innovates Technology Futures (AITF) developed and tested a proof of concept for a rapid farm-level detection test designed help ensure growers only plant disease-resistant canola varieties and improve overall management of blackleg disease.
In this project, researchers developed an assay to test a class of enzymes, the chitinases, as a potential method for predicting resistance or susceptibility to uncharacterized L. maculans isolates present in the field. One way that canola plants respond to pathogen attack is by the production of enzymes that inhibit growth of the pathogen. The principle of this assay was to assess the differential expression of chitinase isozymes (slightly different forms of the chitinase enzyme) by susceptible and resistant B. napus cultivars in response to challenge by L. maculans.
The study included the collection of isolates and plant materials in the field and disease nurseries, followed by testing in growth chambers and in the greenhouse. Several B. napus cultivars were used in this study: Q2, Surpass 400, Quinta, Westar, Cultivar A, Cultivar B and SP Banner. For initial testing, three L. maculans isolates originally obtained in east-central Alberta were chosen on the basis of differential response towards the cultivars included in the study.
From the study results, researchers were unable to identify a relationship between host/pathogen compatibility/incompatibility and isozyme expression. The results showed that a differential expression of chitinase isozymes was observed for some L. maculans isolate /B. napus combinations, but not for others. Cross-tabulation of virulence testing with expression of Isozyme B showed that expression of this chitinase was not consistently associated with either susceptible or resistant reactions to infection by L. maculans. Researchers also concluded that other approaches to predicting cultivar performance when challenged with specific L. maculans populations appear to be more practical and promising, and would require less investment of time and resources to develop. Overall, the study concluded that use of chitinase expression is not a practical tool for diagnostic use.
Full Report PDF: Rapid Farm-Level Detection of Blackleg Pathotypes - Proof of Concept