Genetic structure and seed germination in Portuguese populations of Cheirolophus uliginosus (Asteraceae): Implications for conservation strategies; Estructura genética y germinación de semillas en poblaciones portuguesas de Cheirolophus uliginosus (Asteraceae): Implicaciones para su conservación

Genetic structure and seed Germination in PortuGuese PoPulations of Cheirolophus uliginosus (asteraceae): imPlications for conservation strateGies.— Cheirolophus uliginosus is a threatened species, endemic to the Atlantic coast of the Iberian Peninsula, where it occupies a few restricted localities. In our study we analysed the patterns of cpDNA haplotypes variation and reproductive success—germinability—among seven Portuguese populations of varying size. the aim was to examine the reproductive performance of Ch. uliginosus related to genetic structure and population size. the results showed very low within-population variability of cpDNA markers. Our study indicates that the germination rate is significantly reduced in small populations (< 50 plants) whereas medium (50–250 individuals) and large-sized (> 250 individuals) do not show any constraint. In the search for plausible causes explaining the lower germination success in the smallest populations, ecological concerns and genetic isolation must be taken into account. Besides, in large-sized populations of Ch. uliginosus (> 250 plants) a higher incidence of predispersal seed predation was observed, maybe affecting their sexual reproductive response. Finally, smaller populations—presenting a reduced reproductive success—contain also the most evolutionary distant haplotypes, so their conservation should be a priority.