Herbicide Resistance in Canola: From Cytogenetics to CRISPR-based Innovations

Herbicide resistance in canola (Brassica napus) has emerged as a major agricultural challenge, reducing herbicide efficacy, increasing weed pressure, and threatening sustainable crop production. This review examines the historical development of herbicide-resistant canola, focusing on the evolution of resistance mechanisms such as target-site resistance (TSR) and non-target-site resistance (NTSR), as well as the rising prevalence of multiple and cross-resistance in weed populations. Cytogenetic insights, including chromosome mapping and gene duplication studies, provide a deeper understanding of the genetic basis of resistance. Recent advancements in genomic breeding, marker-assisted selection (MAS), and CRISPR-mediated genome editing offer promising strategies for developing resistant cultivars with improved weed management efficiency. Additionally, integrating genomic data with agronomic practices—such as diversified crop rotations, herbicide mixtures, and biotechnological interventions—is essential to mitigate resistance evolution. However, challenges such as gene flow to wild relatives, regulatory constraints, and the environmental impact of genetically modified crops necessitate a balanced approach to herbicide resistance management. This review underscores the importance of combining cytogenetics, molecular breeding, and advanced genome editing tools to develop sustainable and resilient canola cultivars. Future research should focus on novel resistance genes, alternative herbicide targets, and eco-friendly weed management strategies to ensure long-term productivity and environmental sustainability.