Effects of salinity and temperature on seed germination in a Japanese endangered halophyte Triglochin maritimum (Juncaginaceae)

Effects of salinity and temperature were examined on the seed germination of an endangered halophyte in Japan, Triglochin maritimum (Juncaginaceae). Germination tests were carried out at three salinity levels (0 200,400 mM NaCl) in which seeds were exposed to increasing-or decreasing temperatures. Effects of moist-hilling pretreatment (stratification) in 0, 200 and 400 mM NaCl on seed germination at 0, 200 and 400 mM NaCl, respectively, were also examined. Under the highest salinity condition (400 mM NaCl), no germination was observed. The seeds germinated very well (88%) in fresh-water after 5-month moist-chilling pretreatment. Longer moist-chilling pretreatment resulted in higher germination percentages. Moist chilling pretreatment in 0, 200 and 400 mM NaCl for 5 month enhanced germination percentages to 10% (in 400 mM NaCl) -88% (in 0 mM NaCl).