Influence of temperature and salinity on the germination of Limonium tabernense Erben from Tabernas Desert (Almería, SE Spain)

Abstract

The effects of salinity, temperature and their interactions on germination were evaluated for Limonium tabernense Erben, a halophytic perennial endemic plant, which grows in arid environmental conditions in the Tabernas Desert (SE Spain). Experiments were conducted to determine the effects of different salinities (0, 100, 200 and 400mM NaCl) on seed germination under different temperature regimes (20/10, 25/15, 30/20 and 35/25°C), both in a 14/10h light and dark photoperiod. Germination was substantially delayed and significantly reduced by increasing NaCl levels. Maximum germination occurred in the lowest saline media (100mM NaCl) and distilled water (0mM NaCl) at the temperature 20/10°C. No seeds germinated at concentrations higher than 200mM NaCl at highest temperature (35/25°C). Increasing salinity delayed the beginning and ending of germination, reduced final germination percentage and increased mean time to germination. The interactive effect of temperature and salinity on final germination and germination rate was significant, indicating that the germination response to salinity depend on temperature. Seeds recovered their germination capacity after transfer from saline solutions to distilled water. Germination recovery was affected by salinity, temperature and their interaction.