The purpose of this studywas to focuson screening native plants capable of absorbing heavy metal chromium (Cr)to treat contaminated soil. By field investigation method combined with a greenhouse experiment to determine growth capacity, critical points, TF and BF coefficient, 48 plant species with their outer morphology specific to heavy metal hyper-accumulator were collected. After examining scientific names, making a checklist of plant species, the results showed that there were 16 orders, 21 families, 37 genera capable of accumulating heavy metals. Among them, 4 plant speciesweresurvived in Cr contaminated soil from 150- 350mg/kg dried soil concluding: (1) Cyperus rotundusL., (2) Cynodon dactylon(L) Pers., (3) Amaranthus spinosusL., (4) Solanum nigrumL. in which Solanum nigrumL. is dominant in terms of both biomass andthe transportas well asbioaccumulation coefficient. Under normal farming conditions and soil contaminated with Cr concentration of 150- 350 mg/kg, Solanum nigrumL.hasgrownwell and attainedthe highest Cr treatment efficiency in contaminated soil from 150- 250 mg/kg dried soil.
A study of Cadmium (Cd) absorption by Solanum nigrumL.(S. nigrum) was conducted through using outdoor pot- culture experiments from March to June 2015. Results showed that S. nigrumbiomass compared with the controlwas not significantlydifferent(P<0.05) under the concentration of 10- 25mg/kg of Cd in soil. The ability to accumulate Cd in the above-ground parts was greater than 100mg/kg dry biomass; TF and BF coefficient was greater than 1. The results of this study demonstrated that S. nigrumis a Cd-hyperaccumulator. This is an important finding that may contribute to solve heavy metal pollution problems as well as to apply phytoremediation in specific situations.
