TY - JOUR TI - Emergence and diversification of a highly invasive chestnut pathogen lineage across southeastern Europe AU - Stauber, Lea AU - Badet, Thomas AU - Feurtey, Alice AU - Prospero, Simone AU - Croll, Daniel A2 - Castric, Vincent A2 - Weigel, Detlef A2 - Laine, Anna-Liisa A2 - Castric, Vincent VL - 10 PY - 2021 DA - 2021/03/05 SP - e56279 C1 - eLife 2021;10:e56279 DO - 10.7554/eLife.56279 UR - https://doi.org/10.7554/eLife.56279 AB - Invasive microbial species constitute a major threat to biodiversity, agricultural production and human health. Invasions are often dominated by one or a small number of genotypes, yet the underlying factors driving invasions are poorly understood. The chestnut blight fungus Cryphonectria parasitica first decimated the North American chestnut, and a more recent outbreak threatens European chestnut stands. To unravel the chestnut blight invasion of southeastern Europe, we sequenced 230 genomes of predominantly European strains. Genotypes outside of the invasion zone showed high levels of diversity with evidence for frequent and ongoing recombination. The invasive lineage emerged from the highly diverse European genotype pool rather than a secondary introduction from Asia or North America. The expansion across southeastern Europe was mostly clonal and is dominated by a single mating type, suggesting a fitness advantage of asexual reproduction. Our findings show how an intermediary, highly diverse bridgehead population gave rise to an invasive, largely clonally expanding pathogen. KW - Cryphonectria parasitica KW - fungal pathogen KW - invasive species KW - population genomics JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -