In Vitro Studies on Seed Germination of the Mediterranean Species Anthyllis barba-jovis to Facilitate Its Introduction into the Floriculture Industry

Anthyllis barba-jovis is a salt and drought tolerant evergreen shrub, native of the western-central Mediterranean coasts, with ornamental characteristics that make it worthy to be exploited for commercial use as an ornamental and landscape plant. Therefore, the present study aimed to determine germination as affected by seed-coat, temperature, photoperiod, and seed storage period, as a first approach to introduce the species into the floriculture industry. Seeds scarified or non-scarified, recently harvested or after storage at room temperature in the dark for 12, 24, or 36 months were placed for germination in vitro on Murashige and Skoog (MS) medium, under 16 h photoperiod (LD) or continuous darkness, at 5–35 °C, at 5 °C intervals. Seed pre-treatment by mechanical scarification with sandpaper highly promoted their germinability. Seeds germinated in all treatments at varying percentages. Photoperiod had no significant effect on germination. Cardinal temperatures for germination were defined at 35 °C and 5 °C (possibly even lower, particularly for up to 1-year-old seeds, which germinated at 30–58% at 5 °C when scarified). Temperatures from 15 to 25 °C were optimal for germination of recently harvested or 1-year-old seeds (82–98% when scarified), whereas older seeds germinated at higher percentages at 20 °C (65–97% when scarified), thus long storage affected both the range of optimal temperatures for germination and the germination percentage. Storage reduced germination mostly of non-scarified seeds. Three years after harvesting A. barba-jovis seeds germinated at high percentages (77%) at 20 °C and LD when scarified, while without scarification germination was less than 10% in all treatments.