Water Relations of Atriplex canescens as Affected by the Salinity and Moisture Percentage of Processed Oil Shale1
- Steven G. Richardson and
- C. M. McKell2
Osmotic adjustment through ion uptake is believed to be an important plant mechanism for ameliorating osmotic stresses imposed by high salt concentrations in the soil solution. Differential growth responses of plants to various salts may be due at least in part, to differences in osmotic adjustment because of differential ion uptake. A greenhouse study was conducted to determine whether differences in growth of fourwing saltbush (Atriplex canescens) in response to Na2SO4 and MgSO4, the two major salts in processed oil shale, might be due to differences in the effects of the salts on osmotic adjustment or other aspects of plant water relations. Magnesium sulfate was more detrimental to the growth of Atriplex canescens than was Na2SO4 when added at equal osmotic concentrations to leached processed oil shale. Cation concentrations in leaves were greater in response to Na2SO2 than to MgSO2. However, the osmotic and turgor potentials, determined from pressure-volume curves developed with a pressure bomb and analytical balance, indicated that no differences in osmotic adjustment occurred due to chemical composition of the added salts. Osmotic adjustment did occur in response to reduced moisture percentage of the processed oil shale. Differences in leaf diffusive resistance indicated that water stress was greater in MgSO4-treated plants than Na2SO4-treated plants. Leaf size and succulence weregreater on Na2SO4-treated plants than MgSO4-treated plants.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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