Effect of salinity and temperature on the germination of Spergularia marina seeds and ameliorating effect of ascorbic and salicylic acids.

Spergularia marina (Caryophyllaceae) is a halophytic species and widely distributed among the sea shores of Turkey. Its seeds maybe unwinged or winged. Laboratory experiments were conducted to determine the effects of salinity (0, 50, 100 and 500 mM NaCl) and temperature (10, 15, 25, 30, 35 degrees C) on seed germination. S. marina showed 73.3% germination in non-saline controls at 25 degrees C. No germination occurred at 30 degrees C and 35 degrees C. Seed germination of Spergularia marina was significantly affected by salinity levels, temperature and their interactions. Maximum final germination percentage occured under the lowest salinity condition (50 mM) and distilled water at 25 degrees C. Seed germination was completely inhibited by 500 mM NaCl, although seed germination rate was not affected by salinity. Recovery germination was greatest in 500 mM and at 25 degrees C. The rate of germination was significantly affected by temperature (p < 0.01). The germination percentage of the seeds pretreated with 40 mM and 60 mM L-ASA in 50 mM and 100 mM NaCl was improved compared with that of untreated L-ASA. Addition of 0.5 mM salicylic acid (SA) improved the germination in 50 mM NaCl.