Seed germination of six coastal plant species of the Baltic region: effect of salinity and dormancy-breaking treatments

Abstract

AbstractSeed salinity tolerance and dormancy play important roles in germination behaviour. The effects of NaCl concentration and different dormancy-breaking treatments on germination were determined for six species growing on the coasts of the Baltic Sea or the Gulf of Riga: Juncus balticus, Triglochin maritima, Triglochin palustre, Anthyllis maritima, Linaria vulgaris and Linaria loeselii. Germination percentages were significantly reduced at NaCl concentrations >100 mM. Germination of J. balticus, T. maritima and T. palustre, but not that of A. maritima and L. vulgaris, recovered after seeds were rinsed with distilled water. Seeds of J. balticus were non-dormant; those of A. maritima had physical dormancy; and those of T. palustre, T. maritima, L. loeselii and L. vulgaris had non-deep to intermediate physiological dormancy, which was broken by cold stratification or gibberellic acid. The seeds of plants growing in habitats periodically exposed to sea water (coastal meadows) were characterized by greater salinity tolerance than seeds of plants growing in habitats less exposed to sea water (dunes).