engleski

SEED DORMANCY AND GERMINATION OF Ligularia sibirica (L.) Cass. POPULATION FROM NATIONAL PARK PLITVICE LAKES, CROATIA

Ligularia sibirica (L.) Cass. is a boreal Euro-Asian species which colonizes a wide range of habitats from East Asia, along the southern Siberia, Belarus, Ukraine and European parts of Russia. In the southwestern-most parts of its areal it is very rare, found mostly in small, scattered and isolated mountainous populations with decreasing population trends. In Croatia, Ligularia sibirica is considered a postglacial relict. This species is spread over only a single, isolated locality within the territory of National park Plitvice Lakes and it is assessed as critically endangered (CR) in Croatian Red Book. In the Botanical garden of the Faculty of Science, University of Zagreb, we conducted a germination study to shed light on the topic of Ligularia sibirica seed ecology and consequently advance its conservation effort. The freshly matured seeds were exposed to cold or warm stratification in duration of four to sixteen weeks and their germination was investigated through different regimes of incubation parameters, i.e. illumination (light/dark) and temperature (5, 15/6, 23 °C). Ligularia sibirica had higher germination values after cold stratification and presumably L. sibirica seeds had non-deep physiological dormancy. The overall germination rate was 45% which indicates that the only Croatian natural population of L. sibirica is genetically impoverished from inbreeding, therefore careful management including appropriate ex situ and in situ conservation programs are necessary for this small population to survive.

seed ecology, ex situ conservation, endemic species

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