Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Biology

Program Name/Specialization

Biological and Chemical Sciences

Faculty/School

Faculty of Science

First Advisor

Zhongwei Zou

Advisor Role

Supervision, Mentorship and Guidance, Collaboration on Experimental Design, Grant Funding, Thesis Feedback

Abstract

Canola (Brassica napus) is Canada's number one cash crop, with an estimated 90% of canola being grown and consumed in export markets. In 2025, Canadian farmers produced 21.8 million metric tonnes of canola, a 13.3% increase from the previous year's 19 million metric tonnes. However, despite 2025 showing a higher harvest, crop yields are affected by various factors, including crop death, which results in yield losses of up to 50%. These factors influence the total annual yield. Yield losses are estimated to result from environmental factors such as climate change and disease pressure. One such disease is Verticillium stripe, caused by the fungal pathogen Verticillium longisporum, first discovered in Manitoba in 2014. Infection severely affects the plant's roots and vascular system, causing crop death and yield losses of up to 50%. Verticillium longisporum can be classified into three lineages, A1/D1, A1/D2, and A1/D3, each with distinct virulence characteristics. This study aimed to characterize the lineage and mating types of V. longisporum isolates from Manitoba, and to perform a functional analysis of the transcription factor NAC19 (NAM, ATAF1/2, and CUC2) overexpression in B. napus-V. longisporum interactions. Results indicated that the predominant lineage of western Canadian V. longisporum is A1/D1, with a limited number of A1/D2 lineages also characterized. All isolates were also confirmed to be mating type 1. Subsequently, the phenotypic results for OEBnNAC19 plants showed enhanced resistance to V. longisporum infection compared with the wild-type Westar. Analysis of defence-genes showed differential expression at 7 and 14 days post inoculation, suggesting that both SA and JA signalling pathways are involved in the defence response. OEBnNAC19 can enhance canola's resistance to Verticillium longisporum and should be used to develop pre-breeding lines to alleviate verticillium stripe disease pressure on canola.

Convocation Year

2026

Convocation Season

Spring

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Available for download on Friday, April 28, 2028

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