Main Goal

We aim to develop molecular tools allowing the precise identification of races/pathotypes of P. sojae and H. glycines present in Canadian soybean fields in order to assist end-users in the development and selection of varieties resistant to these pathogens/pests.

For all three major diseases/pest of soybean in Canada, the most reliable and economical method to reduce losses is the use of resistant varieties. In the case of PRR and SCN, one major challenge resides in the ability to develop/choose varieties that confer resistance to the specific races/pathotypes of the pathogens that are predominant in a given area. In the absence of information on the genetic diversity of P. sojae or H. glycines present in fields, breeders and growers cannot make an informed decision on how to exploit genetic resistance. This project proposes to develop diagnostic tools allowing the first comprehensive characterization of P. sojae and H. glycines populations present in soybean fields in Canada. This is not a problem for Sclerotinia sclerotiorum as there are no races of this pathogen and therefore no race-specific resistance genes.

The following sub-objectives will be instrumental to reach the main goal.

Act.3.1 Development of tools to identify races/pathotypes of P. sojae

3.1a Establish a collection of P. sojae isolates that represent the most common races found in Canadian fields

3.1b Characterize all P. sojae isolates by GBS and/or whole-genome sequencing and identify SNP markers that are unique and discriminant for each race of our collection.

3.1c Develop a multiplex PCR approach to identify specific races of P. sojae from plant and soil samples

3.1d Develop a comprehensive map of the presence and distribution of P. sojae races across soybean fields in Canada

Act.3.2 Development of tools to identify pathotypes of H. glycines

3.2a: Identify genetic markers associated with HG types (pathotypes) of H. glycines by GBS;

3.2b: Compare virulence genes of different HG types using capture array technologies based on the effector complement of H. glycines;

3.2c: Develop quantitative PCR assays for the rapid identification of HG types.

3.1.1) Development of a multiplex PCR-assay based on primers specific to each race

3.1.2) Development of a comprehensive map detailing the distribution and pathotypes of P. sojae throughout soybean production areas in Canada.

3.2) Development of a multiplex PCR-assay based on primers specific to each pathotype