Seed germination in Abies nebrodensis (Pinaceae)

Abies nebrodensis is a strict Sicilian endemic species, listed as “Critically Endangered” in the IUCN Red List of Threatened Species. Seed production highly varies annually and among specimens. The species is affected by a very low seed germination rate, mainly depending on the large number of empty seeds (from 68 to 96%). The embryo presence in seeds increases with increasing seed size and weight. Optimal germination rate (61%) was achieved at constant 5°C in the darkness. The low proportion of embryos in seeds is a relevant threat for A. nebrodensis conservation, as it affects the intrapopulation genetic diversity and reduces the potential genetic variability of seed accessions preserved in a gene bank collection.