The effect of different salts of sodium and potassium on the germination of Atriplex prostrata (chenopodiaceae)

Abstract

Seed germination and early growth of the halophyte Atriplex prostrata Boucher were measured to compare sodium chloride (NaCl) to other salts to determine if the inhibitory effects of salinity were osmotic or due to a specific ion inhibition. Seeds of A. prostrata were germinated in solutions containing NaCl, potassium chloride (KC1), sodium sulfate (Na₂SO₄), and potassium sulfate (K₂SO₄) at concentrations with osmotic potentials equal to 0, ‐0.75, ‐1.0, and ‐1.5 MPa. Percent germination and shoot length was usually inhibited only at the lowest osmotic potential (‐1.5 MPa). However, at ‐1.5 MPa the rate of germination was more inhibited by sodium salts than by potassium salts. Ungerminated seeds pretreated with salts had recovery germination percentages in distilled water that were equal to that of the freshwater controls indicating that the previous effect of these salts was due to osmotic inhibition rather than a specific ion toxicity.