Phenotypic differences among ploidy levels of Phragmites australis growing in Romania

This paper presents data showing phenotypic differences of Phragmites australis (Cav.) Trin. ex Steud. (Common reed) growing in Comana lake and in the Danube Delta (Romania). In Comana lake, tetra- and octoploids were found, whereas in the Danube Delta also hexaploids occurred. In freshwater habitats, shoots of octoploids were longer and thicker with more nodes than those of tetraploids. Panicles of octopoids were also larger than those of tetraploids. The number of alive leaves did not differ between ploidy levels. Total leaf area, however was higher of octo- than of tetraploids, which indicates that octoploids produced larger leaves. Octoploids also had thicker rhizomes. No differences in allocation of dry matter to leaves, stems, and leaves (blades and sheaths) were found between tetra- and octoploids. Both tetra- and octoploids shoots were among the tallest in the central Danube Delta. Tetraploids were morphologically more diverse in Comana lake than in the central Danube Delta. Within areas, size of shoots could, however, not be related to water depth. Salinity reduced shoot size of tetraploids considerably. Under saline conditions, no differences in morphology of shoots were found between tetra- and hexaploids. ([KEYWORDS: Danube Delta; water depth; salinity;environmental stress; plant morphology; Phragmites australis