Partner und Internationale Organisationen
(Englisch)
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A, B, BG, CY, CZ, DK, FIN, F, D, GR, H, IRL, I, NL, N, PL, P, RO, SK, E, S, CH, GB
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Abstract
(Englisch)
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In a previous SPPE-project and by means of in-vitro-breeding, selection techniques, we obtained about 106 tobacco variants (Nicotiana tabacum ssp.) with increased metal accumulation properties. Best of them show a shoot accumulation that is 5-7 times as great for copper, 2-5 times as great for cadmium, and 0.5 times as great for zinc, when compared with the parent plants. After having passed a first set of pot experiments on metal-contaminated soils, 17 of these somaclonal tobacco variants with a signi-ficantly improved heavy metal shoot uptake were identified. The main subject of our work within the Swiss COST Action 837 is now to carry out a «fine tuning» to evaluate and assess the most promissing tobacco varieties for future phytoextraction use of heavy metals from soil. This validation will be done on different soils in greenhouse and under freeland conditions, and will include the most promissing mobilisation treatment. The scientific work will include investigations of the plant uptake and yield performances under multiple soil conditions, and the indis-pensable investigations of the genetic stability. An overall evaluation of the most efficient metal accumulating and extracting tobacco variants, mobilising agent, and treatments under labortatory and field conditions will be done in the second year. The work to be done is divided into two workpackages, as follow: Workpackage I: Assessment of the remediation potential of the best tobacco variants for extraction of heavy metals from metal contaminated soil. To assess the metal accumulation and extraction potential of these new in vitro-breded tobacco clones, a «fine tuning» is now carrying out in the first year. Thereby a special designed mini pot experiment (growth chamber) on a well defined top soil artificially spiked with Cd, Zn and Cu in two singular concentration levels (low, high), according to increased «plant available» metal contents is used to assess each of these selected tobacco variants under well controlled conditions and to find out the entire potential of these in vitro bred and selected tobacco variants. In addition a metal spiked mix concentration was prepared, in order to find out, whether the different metals are competing the uptake and translocation into the harvestable parts of the plants. An non-spiked soil is used as control of the complexe uptake process. Each metal contaminated level included in this experimental design is controlled by original motherclones, as well. Target of that experiment is to find out a set of the most efficient tobacco variants related to the metal uptake and removal from metal polluted soil and their tolerance against metal related stress and diseases. Workpackage II: Characterisation of tobacco variants with the best accumulating capacities and assessment of their genetic stability. The investigations of both workpackages, dealing with assessment of the phytoextraction potential and the genetic stability, are an indispensable step towards future successful phytoextraction use of these «new» tobacco genotypes. The genetic stability of most promissing clones will be investigated from F1-seeds, obtained from a self pollination, that will be produced in the first year. Tereby also possible epigenetic changes among the tobacco variants will be investigated. This work will bo done in the growth chamber and under real fild conditions, and also growth and yield will be tested in a meanwhile running mini-plot field experiment at Rafz.
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