| Petroleum extraction from oil sands in Alberta produces tailings with high ion concentrations (Na+, Cl-, and SO42-). Composite tailings retain water, leaving portions of deposits waterlogged. A potential species for revegetation of tailings is black spruce (Picea mariana (Mill.) B.S.P.). It is flood tolerant, so identification of salt tolerance characteristics could allow screening of planting stock. Salt affects plants by inducing water deficit, and ion toxicity. This study used controlled environment and field experiments to examine relationships between drought tolerance and salt tolerance in black spruce. Plant responses to water deficit were examined by measuring water relations parameters derived from Pressure-Volume curves. Parameters indicating drought tolerance were predictors of injury caused by salt stress. These included: lower relative water content at the turgor loss point; higher relative water content of the symplast; lower osmotic potential at the turgor loss point; lower maximum bulk modulus of elasticity; and higher osmotic amplitude for turgor maintenance. |
