MSc Final Oral Examination: Justin Robson


Interested Members of the University Community are invited to attend the Final Oral Examination for the Degree of Master of Science of  Justin Robson  of the Department of Plant Agriculture 

Date:  Monday, January 18th, 2021
Time:  1 PM 
Method: Via Zoom videoconferencing -
Meeting ID: 967 1255 1301
Passcode: 275752 

Thesis Title: Management of Plasmodiophora brassicae using fumigants and defense signalling 

Advisory Committee 
Dr. Mary Ruth McDonald, Advisor
Dr. Bruce D. Gossen, Co-Advisor
Dr. Katerina Jordan

Examination Committee
Dr. Manish Raizada, Chair
Dr. Mary Ruth McDonald
Dr. Bruce D. Gossen
Dr. Josh Nasielski                                                                  


Clubroot (Plasmodiophora brassicae) is a soil-borne disease that attacks Brassica crops, including canola. Management options are limited and the defense response in plants is not fully understood. Selected rates of the fumigants metam sodium and chloropicrin, along with solarization, were tested in controlled environment and fields studies. Fumigants required sealing with high-grade impermeable film to be effective. Chloropicrin was most effective at reducing disease severity but neither fumigant eliminated resting spores from soil. No effect of solarization was identified but this approach warrants more study. A split-root system for growing and inoculating canola was developed to examine gene expression in roots challenged with P. brassicae. Two defence genes, BnOPR2 and BnCCR, were consistently amplified. Results differed between the two experiments which indicated that gene expression differed between the root sections. The split root method will be valuable for further studies on host responses to infection by P. brassicae.