Growth, survival and metal accumulation of Samanea saman and Leucaena teucocephala in soil-amended mine tailings from copper mine in Zambales, Philippines

Pot experiments were conducted to assess the effects of different substrates on the growth performance, metal accumulation and phytoremediation potential of Leucaena leucocephala (Ipil-ipil, Tagalog) and Samanea saman (Acacia, Tagalog) for use in revegetation of metal-contaminated soils. One type of substrate used was soil collected from a tailings pond from an abandoned copper mine located in Southwest of Luzon, San Marcelino, Zambales, Philippines. The other substrates used were sawdust and inorganic fertilizer. Another treatment also made use of MYKOVAM. The growth parameters considered were percentage germination, height, shoot/root growth, arbuscular formation, and root/shoot ratio. Leaf nuclei were used to assess DNA damage using the Comet assay technique. The present study demonstrated that both S. saman and L. leucocephala could be used for revegetation of copper mine tailings. S. saman was found to have greater ability to accumulate Pb while L. leucocephala was better in accumulating Cu. Application of MYKOVAM and combination of inorganic fertilizer and sawdust were shown to increase the root Pb and Cu uptake of both legume plants. Legume species were also found to accumulate higher concentrations of Cu and Pb in roots than in shoots which could make them potential choices for phytostabilization in copper mine soils. The results of the Comet assay showed that exposure of plants to Pb and Cu result to considerable DNA damage as shown by the tail moment values. No significant difference was found on the DNA damage of plants grown using various substrates