Effect of heavy metals accumulation on the growth and essential oils content of Rose Geranium (Pelargonium graveolens L.)

The objective of this study was to investigate the accumulation of Cd, Ni and Pb and their distribution in the aboveground and underground biomass of Rose Geranium (Pelargonium graveolens L.), as well as the effect on the plant’s content and quality of essential oils. For this purpose, a pot experiment was conducted using a neutral to alkaline, sandy-loam soil, treated and equilibrated with four different levels of either Cd, Ni or Pb, in five replications, whereas control pots received no application. Five-weeks old plantlets of Rose Geranium were transplanted to the pots containing the different soil mixtures and plant analysis of the aboveground tissue was conducted eight weeks later. At the end of the experiment, aboveground and underground biomass of the plants was collected and air dried until constant mass. Parts of dry samples were used for ICP analyses and quantification of the heavy metal content. Hydrodistillation was also used to extract essential oils from the dry tissues and GC-MS analyses was carried out. Results show metal- and pollution level- dependent accumulation of the three metals under investigation in the roots and the aerial parts of the plants. Essential oil profiles from all treatments will also be presented showing the effects of the heavy metal pollution on their quality and content.