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Centaurea cinerariasubsp.circaeis an endemic plant with a distribution area limited to Circeo mountain (Lazio, Italy), whose population was estimated in a very low number of individuals. The aim of this work was to investigateex situconservation strategies such as achene collection andin vitroplant propagation, which will permit to carry out restoration programmes. The test carried out on the achenes demonstrated that only 5.5% of them were morphologically healthy. Seed germination tests showed that seeds do not display dormancy and that germination does not require pre-treatments. The higher germination rate (67.5%) was observed under a photoperiod of 12/12 h (light/dark) and temperature regime +20/+10°C. Thein vitrostudies demonstrated that micropropagation, acclimatization and the transfer outdoors ofC. cinerariasubsp.circaeare not particularly difficult: 74% of shoot explants in a Murashige and Skoog (MS) medium added with 0.5 mg/l benzylaminopurine and 2 mg/l kinetin formed multiple shoots; 100% of shoots rooted in the MS medium added with 0.5 mg/l indole-3-butyric acid and over 90% survived the acclimatization phase. After been transferred outdoors, the totality ofin vitro-propagated plants bloomed and appeared morphologically indistinguishable from wild plants. Preliminary chemical analyses showed a similar profile forin vitro-propagated and wild plants. [ABSTRACT FROM AUTHOR]

A reintroduction experiment of Bidens cernua L., a species included in the Red List of Italian Flora, was carried out at Lake Posta Fibreno (Lazio, central Italy). There were no significant differences in the length of the phenological phases between the reestablished population (Pr) and the natural one (Pn). The length of the phenological cycle, from seedling emergence to the end of the fruiting phase, was 207 ± 3 days. The relative growth rate in height (RGRH) and relative growth rate in mass (RGRm) were significantly (p < 0.05) higher for Pr (0.047 ± 0.001 cm cm-1 d-1 and 0.057 ± 0.001 g g-1 d-1, respectively) than for Pn (0.045 ± 0.001 cm cm-1 d-1 and 0.055 ± 0.001 g g-1 d-1, respectively). There were significant (p < 0.05) differences for plant height (H) and total leaf area per plant (TLA) between Pr and Pn, the latter having the lower values. Total plant dry mass (PDM) was significantly higher for Pr, and the above-ground/below-ground dry mass ratio was 6.7 ± 0.4 and 4.7 ± 0.2 for Pr and Pn, respectively. On the whole, results demonstrate that the Pr of B. cernua has the potential to develop in a manner that is demographically similar to the Pn present in the Posta Fibreno Lake protected area. Abbreviations: H, plant height; LA, mean leaf area; LM, leaf dry mass; PCA, principal component analysis; PDM, total plant dry mass; Pn, natural population; Pr, reestablished population; RGRH, relative growth rate in plant height; RGRm, relative growth rate in plant dry mass; SLA, specific leaf area; TLA, total leaf area per plant [ABSTRACT FROM AUTHOR]