Genomic evolution of adaptive traits in the globally invasive weed Ambrosia artemisiifolia : Find an Expert : The University of Melbourne
<p> Ragweed is native to North America and is now a globally invasive weed whose pollen is extremely allergenic. Australian ragweed populations are restricted to parts of Queensland and New South Wales, potentially limited by the extent of genetic variation available for local adaptation that could facilitate its spread. Our modelling suggests that the supply of genetic variation from North America could dramatically help colonise Australia further. </p> <p> However, we have no empirical understanding of how functional variation is acquired by Australian ragweed and whether North American source populations might supply such variation in an ecological context. </p> <p> This project will connect field experiments in Toronto and genomically-informed niche modelling in Melbourne to assess the risk of ragweed becoming a superweed, able to combine multiple sources of genetic variation to expand its range. Ragweed plants from multiple origins, including Australia, planted at the University of Toronto’s field station will be characterised phenotypically and genomically to measure functional differentiation between ranges. </p> <p> Genetic mapping will identify adaptive loci, or regions of the genome involved in adaptive traits. A newly drafted pan-genome will be used to assess if these adaptive loci are found in genomic regions with high levels of structural variation, such as copy number variants or inversion, likely to reduce the effectiveness of gene flow between populations and ranges. </p> <p> This analysis will shed light on the process of adaptation to novel environments using a weed as model of accelerated evolution, and inform biosecurity models in the context of globalisation and enhanced invasion risk. </p>
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