AWC - Funded Research

Effector based screening for leaf spot complex in Canada

AWC Contribution: $150,000


Wheat leaf spot disease complex is widespread across western Canada, and is composed of several fungal pathogens. Two diseases predominate mainly, tan spot and Stagonospora blotch. Each disease is caused by one fungal pathogen and each pathogen produces multiple toxins, recently named as effectors, which play a major role in disease development. Without these effectors, the fungus is incapable of causing the disease.


The aim is:

  1. Identify new potential effectors in the tan spot fungus and map the corresponding wheat sensitivity loci.
  2. Screen Canadian wheat lines for their reaction to major Stagonospora effectors. The project provides a new approach toward adapting effector-based screening for leaf spot resistances in Canada.

Benefits to producers:

This project aims to identify new necrotic effectors and the corresponding wheat genes. So far, the only identified necrotic effector from Canadian pathogenic populations is ToxA, which was purified in the early 1990s, yet several other uncharacterized effectors induce necrosis. To explain the value of identifying potential toxins: these toxins can be used as a tool to screen wheat germplasm for eliminating susceptibility. Each toxin can be used separately to infiltrate wheat leaves to screen wheat lines. Such an approach has proven highly successful for Australian breeders. In Australia, it was reported that using ToxA as tool for screening reduced susceptibility considerably in short time. According to Vleeshouwers and Oliver (2014): “The area sown to ToxA-sensitive wheat in Western Australia fell from 30.4% in 2009–2010 to 16.9% in 2012–2013. This equates to a reduction of approximately 700,000 hectare. Susceptible wheat typically has 0.3 tons per hectare reduction in yield, or 200,000 tons. Average wheat prices are approximately $250 per ton; therefore, the saving is $50 million.”


Dr. Reem Aboukhaddour is a Research Scientist in cereal pathology in AAFC at Lethbridge Research and Development Centre, Alberta. Her expertise includes understanding dynamics of fungal pathogen virulence and pathogenicity. Her research focuses on wheat yellow rust, leaf spots.