Ionic and Water Relations Responses of Two Populations of a Non-Halophyte to Salinity

Bowman, W. D. 1988. Ionic and water relations responses of two populations of a non-halophyte to salinity.–J. exp. Bot 39: 97–105 Salinity-induced changes in the ionic and water relations in plants from two naturally-occurring populations of the C4 non-halophyte Andropogon glomeratus were measured to detect differences in the capacity to adjust osmotic potentials and in ion content potentially responsible for the osmotic adjustment Pressure-volume curves and leaf ion content were measured in plants from two populations, salt marsh and inland, after long-term exposure to three salinity levels. Osmotic adjustment and decreases in the bulk tissue elasticity occurred to a similar extent in both populations with increasing salinity. Cl− concentrations increased with increasing salinity in both populations, whereas leaf Na+ concentrations increased only in the inland population, but were higher at all salinities in the marsh population. K+ concentrations changed little with increasing salinity. Proline concentrations increased only at the highest salinity level, and did not difler significantly between populations. These results suggest a role for Na+ uptake and regulation in osmotic adjustment in the marsh population, contrasting with studies of salt tolerance in other nonhalophytic grasses