Internal seminar by Vanessa Bieker

Herbarium prospecting reveals the population genomics of invasion in a successful weed

Seminar talk by Vanessa Bieker from NTNU.

Abstract: 

While invasive species are a key driver of the global biodiversity crisis, the drivers of invasiveness remain debated. To investigate the genomic basis of invasiveness in plants, we use the invasive weed Ambrosia artemisiifolia, which was introduced to Europe in the late 19th century. We resequenced 655 ragweed genomes, including 308 herbarium specimens collected up to 190 years ago. We were able to identify the source population of the European invasion. In introduced European populations, we find selection signatures in defense genes and lower prevalence of particular plant pathogens in the invasive range. Together with temporal changes in population structure associated with introgression from closely related Ambrosia species, escape from a specific microbial enemy likely favoured the plant’s remarkable success as an invasive species.