University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Doctoral Thesis:
Ingrid Langer
(2011):
Evaluation for a plant-assisted bioremediation approach: Zn (Cd) accumulation properties of indigenous poplar species and the impact of ectomycorrhizas on phytoextraction characteristics .
Doctoral Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 68.
UB BOKU
obvsg
FullText
- Abstract:
- Phytoremediation, a plant-based in situ approach, is considered an ecologically sensitive strategy to remediate metal affected soils. It may be assisted by ectomycorrhizas known to improve plant vitality on disturbed habitats and to alter metal accumulation. This research aimed to characterize Populus species for use in a Zn(Cd) phytoextraction approach, to evaluate the impact of ectomycorrhizas on P. tremula growth and metal accumulation and to develop a synthesis protocol for P. tremula ectomycorrhizas under controlled conditions. Experimental data reveal differential growth and metal accumulation of P. canescens and P. tremula mainly due to species specificities and their provenance from non-metalliferous/ metalliferous habitats. P. canescens growth was not affected by NH4NO3-extractable soil Zn concentrations up to 60 mg kg-1. Foliar Zn concentrations increased to just above 2000 mg Zn kg-1. Toxicity threshold concentrations and relations between foliar and soil Zn concentrations suggest P. canescens suitable for phytoextraction processes on sites that contain up to 30 mg extractable Zn kg-1. P. tremula exceeded foliar Zn(Cd) concentrations and translocation factors of numerous Salicaceae species. In contrast, extracted Zn(Cd) contents were low due to restricted biomass yields. Studies on ectomycorrhizal P. tremula revealed retarded growth in mycorrhizal as compared to irradiated control treatments which may be explained by side effects of soil irradiation (Fe mobilization), the absence of microbial competitors and by an imbalance of the symbiosis at early growth stage. However, Zn translocation was inhibited at high soil Zn levels indicating barrier functions of the symbiosis. Thus mycorrhizal inoculation of P. tremula may be a promising strategy to enhance phytostabilization of metal-polluted sites. The formation of ectomycorrhizas with P. tremula in vitro was primarily achieved by an improved nutrient composition added to the synthesis medium. It may be applied in non-sterile inoculation techniques that promise more vigorous mycorrhizal plants for use in revegetation and phytoremediation processes.
- Betreuer: Wenzel Walter