Phenotypic traits variation among native diploid, native tetraploid and invasive tetraploid Senecio inaequidens DC. (Asteraceae)

Abstract

Senecio inaequidens DC. is a rapidly spreading plant invader in Europe. In its native range, it occurs at two co-existing diploid and tetraploid cytotypes. To date, only tetraploids are reported in Europe, even though invasive diploids were recorded in other parts of the world. We compared native diploid and both native and invasive tetraploid populations in common gardens in Europe for a suite of life history traits. Diploids were able to develop, showed high biomass production and produced more flower heads than tetraploids. In contrast, winter survival was null for diploids. It was low for native tetraploids, but reached 40% in invasive tetraploids. Results suggested that diploid cytotype tends to an annual life form when grown in Western Europe, with earlier and more abundant flowering. In contrast, the tetraploid cytotype was mainly perennial which may enhance its invasiveness.

Keywords

• Senecio madagascariensis Poir.
• Senecio inaequidens DC.
• ploidy level
• life history
• common garden
• alien plant