Seed germination of six Iberian endemic species – a contribution to enhance plant conservation

Abstract

Biodiversity has been degraded all around the world due to anthropogenic factors. To counteract this worldwide tendency, ecological restoration programs are expanding. In these programs, the use of native herbaceous species, particularly those endemic or threatened, can be promoted by seeding them but germination requirements for most of these species are unknown. Our research meant to fill this gap of information for six Iberian endemic species suitable to use in restoration actions - Digitalis thapsi, Ferula communis subsp. catalaunica, Linaria amethystea subsp. amethystea, Pterocephalidium diandrum, Sanguisorba hybrida, and Silene scabriflora subsp. scabriflora. Their seed germination behaviour was analysed to establish germination protocols for conservation actions. Three germination conditions were used to simulate different sown seasons. Seeds of all species were tested without pre-treatment and subjected to a cold stratification. Seeds of S. hybrida and P. diandrum were additionally tested with a scarification treatment. All species reached their better germination performance under autumn conditions (15/10 °C; 8/16 hours). In conclusion, for all the six Iberian endemic species tested, germination speed and percentage were suitable for their use in native plants reinforcement.