Regeneration of Phragmites australis from rhizome and culm fragments

Regeneration from vegetative fragments is common in plants that occur disturbed and wet habitats but quantitative data comparing regeneration of different plant parts under various environmental conditions are still scarce. Phragmites australis a dominant keystone wetland species widespread all around the world. It spreads both vegetatively by rhizomes stolons generatively seed. Detached culms can support local after disturbance spread populations over considerable distances when transported with water, soil other means. In P. australis, there no information on culm how differs between clones origin what effect environment. Here we studied rhizome six weeks (mid-June to late July 2017) common-garden pot experiment. To simulate scenarios happen nature, placed cuttings (representing propagules) 6-l pots sand surface, buried them 5 cm deep sand. We included 19 distinct representing three phylogeographic groups (North American invasive, North native, European). tested group, part (culm, rhizome), environment (water, buried), ploidy genome size clone using generalized mixed-effect models. A higher percentage than regenerated (69% vs. 37%, respectively). was better water those surface (65%, 50%, 44%, Although found differences among particular (ranging 31% one native tetraploids 90% invasive octoploid), group not statistically significant. However, interacted – natives, while did differ groups. This difference most pronounced sand-surface treatment. Rhizome produced greater culm- root biomass North-American least new Lastly, more slowly (16 13 days produce shoots, respectively), fastest water. Our results point great ability fragments, which cope wide range grow rapidly plants. suggest this played an important role spreading America, whose populations. Culms require be permanently exposed for regeneration, may have also facilitated their drier niche expansion beyond wetlands.