Genetic variability in salt tolerance of selected boreal woody seedlings

Abstract

In order to select woody plant candidates suitable for revegetation of saline-alkaline soils, we tested selected woody plant species and seed lots: Pinus contorta (lodgepole pine), Pinus banksiana (jack pine), Picea glauca (white spruce), Populus tremuloides (trembling aspen), and Alnus rubra, syn. Alnus oregona (red alder). Pre-germinated seedlings were grown for 4 weeks in a greenhouse in a semi-hydroponic system containing 1/2 strength Hoagland solution with additional sodium concentrations (0, 25, 50, 75 mM) and composite tailings release water. A significant interaction between salt treatments and seed lots within plant species as well as between salt treatments and plant species was observed for weight and necrosis, indicating that the plant genotype responded differently to salt treatments. Of all examined woody plant species, jack pine (Syncrude seed source) exhibited the highest percent survival followed by white spruce (Syncrude seed source), red alder (seed lot No. 40457), and lodgepole pine (seed lot No. 7960007). Proportionately ranked means for dry biomass production showed lodgepole pine (seed lot No. 7960007) with the greatest biomass followed by aspen (seed lot No. Syncrude), red alder (seed lot No. Port Renfrew), jack pine (seed lot No. 8960049) and white spruce (Syncrude seed source). The best performing seed lots based on aggregation index which combines both the percent survival and dry weight averages were: red alder (seed lot Nos. 40457 and 45958), aspen (Syncrude seed source), jack pine (Syncrude seed source), lodgepole pine (seed lot No. 7960007). Based on variance components, most of the variation was explained by the treatment and seed lot effects. This reveals the importance of intra-specific variability and that selection should be based not only on inter-specific variation but also on the intra-specific variation for the development of salt-tolerant lines to be used in reclamation of saline habitats. #

Growth of aspen and white spruce on naturally saline sites in northern Alberta: Implications for development of boreal forest vegetation on reclaimed saline soils

“…Characteristics like long leaf lifespan (Greenway et al 1992;Munson et al 1995;Claveau et al 2002), high leaf mass per leaf area (Claveau et al 2005), and high plasticity in crown morphology (Messier et al 1999) that help white spruce survive in low resource availability conditions in the forest understory could also help it survive in unfavorable soils. Khasa et al (2002) also found that white spruce was slow growing, yet had high survivorship in a comparative salinity experiment.…”

“…In one study, every aspen seedling growing in a 2 dS m (1 hydroponic NaCl salinity treatment died within 1 mo (Khasa et al 2002), and in other studies white spruce seedlings had reduced growth at electrical conductivities as low as 0.5 dS m…”

“…latifolia Engelm.) (Khasa et al 2002). White spruce survived (albeit with leaf damage and water stress) for 4 wk in hydroponic solutions with electrical conductivities as high as 6.55 dS m…”

Field performance of alder-Frankia symbionts for the reclamation of oil sands sites

“…Alders have been found to increase soil total nitrogen and carbon (Martin et al, 2003). In addition to thriving in low nitrogen conditions, alders have been reported to support growth in salt affected environments (Graves and Gallagher, 2003;Mertens et al, 2004) and in composite tailings (Khasa et al, 2002). Alder growth was monitored in oil-shale mining detritus and found to be comparable to that recorded on two reference fertile sites (Vares et al, 2004).…”

Soil and groundwater characteristics of saline sites supporting boreal mixedwood forests in northern Alberta

“…Recent laboratory and greenhouse research has focused on quantifying the effects of salinity on boreal species (e.g., Renault et al 1999;Khasa et al 2002;Nguyen et al 2006). We chose a fieldbased approach, using the rare naturally-saline forested sites that exist adjacent to non-forested saline wetlands in the boreal mixedwood region.…”