Exploiting susceptibility genes in canola to improve blackleg resistance

Project Summary

Background

Blackleg is the most widely occurring canola disease in western Canada, causing yield losses every year. Amongst the measures recommended for integrated blackleg management is genetic resistance, especially identification and deployment of specific resistance (R) genes and quantitative resistance (QR) in breeding materials.

However, there are only limited number of R genes available for blackleg resistance breeding, and for almost every R gene known, there is at least one virulent pathogen race existing in western Canada already. QR has been an important element for blackleg resistance in most of the Canadian cultivars, but it is very difficult to improve it, due to its multi-genic nature.

Resistance to crop diseases can also be achieved via the loss-of-function of susceptibility (S) genes, i.e. through a functional disruption of S genes, because these S genes provide a base for compatibility with a pathogen during host-pathogen interactions, allowing or facilitating the infection process.

This study explores potential new S genes related to virulence of blackleg pathogen and severity of the disease.

Objectives

Using a novel approach to identify susceptibility genes in canola and develop additional CRISPR/cas9 knock-out lines with unique blackleg resistance traits for canola breeding, this study will:
1) Assess blackleg resistance levels in the TILLING (Targeting Induced Local Lesions in Genomes) population available at GIFS (Global Institute for Food Security) and UBC-13 mutants available at AAFC Saskatoon.
2) Identify candidate S genes conferring blackleg resistance, and develop associated molecular markers.
3) Generate stable S gene knock-out canola lines using CRISPR/Cas9 technology, evaluate their resistance reaction, develop homozygous pre-breeding resistant lines for tech transfer.

Potential impact

This research aims to generate novel resources and markers for blackleg resistance to be used in breeding for canola varieties with potentially broad-spectrum and durable disease resistance traits.

The approach used in this study may also be useful for resistance against other canola diseases in western Canada. The potential benefit of this research to producers and industry is the continued improvement of variety resistance to all important canola diseases in western Canada.