Grant: Special Research Opportunity Program - Project

Weeds and invasive plants impose a major economic burden on Canada. Weeds lower crop yield, reduce the quality of rangelands, and lead to the expenditure of billions of dollars in chemical and biological control measures. These direct economic costs have been estimated at C$30-50 billion annually in North America. Besides direct economic costs, weeds and invasive plants pose a major threat to Canada's biodiversity, through destruction of native plant and animal habitat. The efficient control of weeds and invasive plants requires knowledge. What makes a weed a weed? Why are some plants able to grow rapidly and invade new habitats while related species do not? Are there repeated genetic changes that occur independently in different weeds? If funded, we will tackle these fundamental biological questions. Little is currently known about the genetic changes that cause weedy species to be noxious while closely related plant species are harmless. We will identify these genetic changes by comparing the genomes of several pairs of weedy and non-weedy plants within the family Compositae. The Composites include ~25,000 species of plants and represent 10% of flowering plants. Several Composites are important crop species, including lettuce and sunflower, yet many others are noxious weeds, including thistle, knapweed, ragwort, and dandelion. This proposal targets many of the worst weeds in Canada. The knowledge generated by our research will have numerous economic benefits to Canada and beyond. Knowing the genetic traits that are critical to weediness will improve the development of herbicides specifically targeted to noxious plants. Targeted herbicides reduce the costs (both economic and ecological) associated with non-specific herbicides and are less toxic to crop and native plant species. Identifying the genetic changes that occur in weeds will allow us to assess the potential risks posed by imported plant species and by genetically modified plants.