Global ploidy levels of Phragmites australis

Phragmites australis is one of the most widely distributed macrophytes in
the world and a model system for biological invasions, as both native and
introduced lineages grow sympatrically across North America. Decades of
research on this tall grass and its biotic and abiotic interactions have
advanced our understanding of plant ecology and plant invasions, including
evidence for the relationship between distribution and specific traits to
particular ploidy levels within the species. Phragmites australis is
characterized by its allopolyploid origins with a base chromosome number
of x = 12, with tetraploids and octoploids dominating worldwide. While
aneuploids of tetraploid plants have been documented with a total
chromosome count around 48 modern high-resolution imaging has found only
euploids in all samples. As P. australis chromosomes have large
heterochromatin terminal knobs that break easily, earlier evidence of
aneuploidy could be the result of artefactual aneuploid counts. The data
published here represents samples the authors collected from the field and
analyzed using flow cytometry and by extracting data from the published
literature. Based on our own data and data extracted from the literature,
we found that tetraploids of this species are the most widely distributed
globally and are the dominant invasive ploidy level in North America.
Higher ploidy levels are more restricted, particularly those greater than
8x.