Objective
- Phenotyping for Verticillium stripe resistance: Implement a qPCR-based assay, alongside traditional visual ratings, to accurately assess Verticillium longisporum colonization in three bi-parental doubled haploid canola populations (>600 lines total; 2 populations from DL Seeds, and 1 from AAFC) under artificial inoculation in greenhouse conditions and natural infection at established field sites.
- Identify genetic loci associated with resistance to V. longisporum: Conduct high-density SNP genotyping and QTL mapping to uncover genomic regions linked to resistance, using phenotypic data from controlled and field environments.
- Develop and deploy molecular markers for marker-assisted selection: Design and validate molecular markers tightly linked to resistance QTL for immediate integration into DL Seeds’ breeding program and to support broader use across the canola industry through open-access dissemination.
Project Description
Developing canola cultivars with resistance to Verticillium stripe (VS) is essential to safeguard yield potential for producers across Western Canada. However, phenotyping for VS resistance presents significant challenges. Unlike many vascular pathogens, V. longisporum does not cause conventional wilting symptoms in canola. Instead, it induces premature ripening, which is difficult to distinguish from natural senescence until after harvest. This subtle symptomatology contributes to high variability in resistance screening and complicates efforts to map the genetic basis of resistance.
To overcome this limitation, we have developed a qPCR-based method for accurate quantification of V. longisporum colonization in plant tissues, as part of our ongoing ADF-funded project (20230249). Building on this progress, we propose to implement this molecular phenotyping approach to screen biparental canola populations developed by DL Seeds and AAFC Saskatoon.
This project has two major strengths:
1. Direct deployment in commercial breeding: By working directly with germplasm from DL Seeds, any resistance loci and associated molecular markers identified will be immediately integrated into DL Seeds’ canola breeding program. This ensures rapid translation into commercial cultivars with improved VS resistance.
2. Industry-wide benefit: All QTL and molecular markers identified will be published in open-access peer-reviewed journals, allowing the broader canola research and breeding community to access and utilize these findings for genetic improvement.
This project represents a critical step toward developing durable, genetically resistant canola cultivars and strengthening the resilience of the Canadian canola industry against Verticillium stripe.
