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

Date: August 28th, 2023
Time: 1 PM 
Location: Room 307, Crop Science Building 

Link for remote participants: https://zoom.us/j/98912135714?pwd=S1o5R29TYUpWUFIrNjBkMFQ1Y3FPQT09
Meeting ID: 989 1213 5714
Passcode: 131705

Thesis Title: Genetic Dissection of Bacterial Brown Spot and Common Bacterial Blight resistance in Common Bean (Phaseolus vulgaris L.) 

Advisory Committee
 Mr. Chris Gillard, Advisor
Dr. Jamie Larsen, Co-Advisor
Dr. Owen Wally
Dr. K. Peter Pauls

Examination Committee
Dr. Helen Booker, Chair
Mr. Chris Gillard
Dr. Jamie Larsen
Dr. Lewis Lukens                              

ABSTRACT 

Dry bean (Phaseolus vulgaris L.) is the most important legume crop for direct human consumption, known for being a high plant-based source of protein, starches, and dietary fibers. Bacterial blights, including bacterial brown spot (BBS) and common bacterial blight (CBB) are recurring constraints in commercial dry bean fields in Ontario, and the development of resistant varieties is the most sustainable and cost-effective management strategy. Screening available germplasm for tolerance against bacterial pathogens and identifying genomic regions associated with disease resistance are crucial steps for developing resistant cultivars. Therefore, the goals of the present study were to evaluate BBS and CBB resistance levels in Ontario-adapted varieties and breeding lines, and to identify quantitative trait loci (QTL) associated with resistance. Field and indoor trials were conducted to phenotype plants for disease severity. These trials included a panel of genotypes with diverse backgrounds and a nested association mapping (NAM) population of recombinant inbred lines (RILs). Molecular markers were tested for their association with disease severity and the NAM population was used for the identification of new resistance QTLs. Disease severity scores varied among genotypes, with scores for CBB being higher than for BBS. A total of 20 and 18 major QTLs were discovered for BBS and CBB, respectively. The identified QTLs can potentially be incorporated into marker-assisted breeding programs to improve the selection of resistant common bean genotypes.