Effect of salinity and temperature on seed germination inLimonium cossonianum

Limonium cossonianum Kuntze is an interesting endemic plant in the southeastern Iberian Peninsula and the Balearic Islands that can be used in wetland restoration and as an ornamental species in saline areas. Experiments were carried out to investigate seed germination responses in L. cossonianum at different levels of salinity (0, 100, 200, and 400 mmol/L NaCl) and under different temperature regimes (20/10, 25/15, 30/20, and 35/25 °C, day/night), both in a 14 h light – 10 h dark photoperiod. Seed germination in L. cossonianum was significantly affected by salinity levels, temperature, and the interaction of both parameters. Maximum germination was recorded in the lowest saline media (100 mmol/L NaCl) and distilled water (0 mmol/L NaCl) at 20/10 °C. No seeds germinated in concentrations above 200 mmol/L NaCl at the higher temperatures. The increase in salinity delayed the beginning and end of germination, reduced final germination percentage, and increased mean time to germination. The rate of germination decreased with an increase in salinity and temperature.