In vitro induction of genetic variability of Dittrichia viscosa to be improved in soil phytoremediation

We evaluated the ability of Dittrichia viscosa (L.) Greuter to extract cadmium and arsenic from agarized substrates with moderately low levels of contamination. This plant spontaneously colonizes contaminated soils and has already been recognized as suitable for the phytoremediation purpose but selection of valuable varieties just starts to be explored. D. viscosa can be considered a plant suitable for phytoremediation and revegetation because it transfers arsenic and antimony from the soil to the root but does not translocate them in large quantities to the aerial parts, which are those eaten by animals. At the same time the large genetic variability in wild populations leave the characterization of this plant specie uncomplete. We compared D. viscosa with other plant species (Nicotiana tabacum L., Solanum lycopersicum L.) in term of metal extraction in in-vitro condition and we observed that its lower cultural needs are not necessarily accompanied by greater phyto-extraction performance. On the basis of plant analyses, we suggest that D. viscosa offers many perspectives for the phyto-extraction of Cd and As from soils with relatively low contamination but it needs genetic improvement to select varieties valuable and reliable for phytoremediation from metal contaminants. We then started a promising process of monitored selection to produce D. viscosa clonal lines with improved and predictable efficacy in phytoextraction of, among other pollutants, As and Cd.