Use of Myriophyllum alterniflorum (Haloragaceae) for restoration of heavy-metal-polluted freshwater environments: preliminary results

Abstract

International audienceMyriophyllum alterniflorum D.C., a poor-known aquatic macrophyte native to north-European freshwaters, was found even in polluted environments from the Vienne river and its tributaries which are often loaded with cadmium and copper near the Limoges metropolis (Haute-Vienne, France). This plant could cope with, to some extent, heavy-metal pollution and is used as a bioindicator since 2009. For these reasons, M. alterniflorum appears as a good candidate for running-freshwater restoration. In this way, the in vitro culture of this plant species was developed to allow a mass production and to study its phytoaccumulation capabilities. The in vitro culture of M. alterniflorum was optimized using Murashige & Skoog's medium allowing rapid growth and biomass production. Phytoaccumulation tests indicate that this species accumulate rapidly heavy metal as a 415-fold increase of cadmium and a 32-fold increase of copper were evidenced on the first 24h after contamination. Moreover, preliminary results concerning the reintroduction of M. alterniflorum clones in degraded and non-polluted areas are also rather encouraging, indicating that this taxon is a good candidate to freshwater restoration