Format: ORAL

Marybel Soto Gomez1, Matilda J. M. Brown1, Samuel Pironon1,2, Pavel Vesel3, Petr Bure3, Tammy L. Elliott3, Frantiek Zedek3, Jaume Pellicer1,4, Flix Forest1, Eimear Nic Lughadha1, Ilia J. Leitch1

1 Royal Botanic Gardens, Kew. Richmond, UK 2 UN Environment Programme World Conservation Monitoring Centre (UNEP-WCMC). Cambridge, UK 3 Masaryk University. Brno, Czech Republic 4 Institut Botanic de Barcelona (IBB). Barcelona, Spain

Angiosperms with large genomes experience nuclear-, cellular- and organism-level constraints that may limit their phenotypic plasticity and ecological niche. Therefore, we test the hypotheses that extinction risk is higher in large-genomed compared to small-genomed species, and that the effect of genome size on risk is mediated by life form, range size, and climatic zone. We combined an angiosperm-wide genome size dataset with the newly released World Checklist of Vascular Plants, the IUCN Red List of Threatened Species and a species-level angiosperm phylogeny to analyse the relationship between genome size and extinction risk across life forms, climates and range sizes using an evolutionary framework. We found that angiosperm genome size and extinction risk are linked directly, and indirectly via range size and climate. Across sampled angiosperms as a whole, genome size is positively correlated with extinction risk. Partitioned by life form, extinction risk increases with genome size in herbaceous species across climates, especially in single-country endemics. However, genome size and risk are not correlated in woody species. Genome size may serve as a proxy for difficult-to-measure parameters associated with resilience and vulnerability, especially in herbaceous angiosperms. Therefore, it merits further exploration as a useful genomic trait for understanding extinction risk and enhancing plant conservation efforts.