Temperature and storage time strongly affect the germination success of perennial Euphorbia species in Mediterranean regions

This study aims to explore the effect of environmental factors (temperature,light, storage time) on germination response and dormancy patterns in eight Mediterranean native wildplants, belonging to the Euphorbia L. genus. In detail, we considered E. amygdaloides subsp. arbuscula, E. bivonae subsp. bivonae, E. ceratocarpa, E. characias, E. dendroides, E. melapetala, E. myrsinites, E. rigida. We collected seeds from natural plant populations and performed germination assays in climatic chambers at seven constant temperatures (from 5 to 35°C, with 5°C increments), and four fluctuating temperature regimes (8/15, 8/20, 8/25, 8/30°C, with a 12/12 h thermoperiod). Germination assays were set up both in dark (D) and in light/dark conditions (L/D, 12/12 h photoperiod), after Short and Long seed Storage (SS around 30 days and LS around 150 days). For all these species, except E. amygdaloides subsp. arbuscula, results show that the final germinated proportions were improved by a long storage perio...