Seed germination of the endemic Armeria helodes (Plumbaginaceae) in Italy

Armeria helodes is a narrow endemic species of Friuli Venezia Giulia (Italy), with a restricted and fragmented range of small populations in remnants of lowland alkaline fens (habitat present in Annex I of the EU Habitats Directive). It is listed as Critically Endangered in the IUCN Red List, nevertheless, best practices for germplasm conservation/germination are still not studied. At maturity, achenes are held inside chaffy bracts (calyx) and their effects on germination are unknown. Therefore, we performed a germination test comparison between fruits embedded in the calyx or free from it, also applying two dormancy-breaking pretreatments (i.e. KNO3, GA3). Approximately 26% of the inspected fruits enclosed inside the calyx were empty or had a small size and coat darkening. The optimal germination rate (60%) was reached when chaffy calyx was removed either before the test or during storage. Dormancy-breaking pretreatments did not increase the germination capacity. Our results represent the first report on the Italian A. helodes germination ability