Abstract: | Bowman, W. D. 1988. Ionic and water relations responses of twopopulations of a non-halophyte to salinity.J. exp. Bot39: 97105 Salinity-induced changes in the ionic and water relations inplants from two naturally-occurring populations of the C4 non-halophyteAndropogon glomeratus were measured to detect differences inthe capacity to adjust osmotic potentials and in ion contentpotentially responsible for the osmotic adjustment Pressure-volumecurves and leaf ion content were measured in plants from twopopulations, salt marsh and inland, after long-term exposureto three salinity levels. Osmotic adjustment and decreases inthe bulk tissue elasticity occurred to a similar extent in bothpopulations with increasing salinity. Cl concentrationsincreased with increasing salinity in both populations, whereasleaf 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. Prolineconcentrations increased only at the highest salinity level,and did not difler significantly between populations. Theseresults suggest a role for Na+ uptake and regulation in osmoticadjustment in the marsh population, contrasting with studiesof salt tolerance in other nonhalophytic grasses |