BIOACCUMULATIONS OF CU AND ZN IN THE LOCAL EDIBLE ULAM CENTELLA ASIATICA

Abstract

The objectives of this study were to determine the accumulations of Cu and Zn in Centella asiatica collected from 13 sampling sites in Peninsular Malaysia and the interactions of Cu and Zn in C. asiatica in different Zn/Cu ratios. The plants were collected (or bought) from 13 sampling sites in 2010. An experiment was carried out under laboratory conditions using Hoagland solution with in the range of 2-6 ppm for Zn and O.l-0.5 ppm for Cu. Cu and Zn accumulations were determined in the leaves and roots after 20 days. Generally, roots showed the highest accumulations of Cu and Zn compared to leaves. The treatment of Zn with Cu (Zn:Cu ratio 6:0.5) exposure significantly reduced the accumulation of Zn in leaves but significantly increased uptake in roots when higher Cu concentration was added (Zn:Cu ratio 6:0.5). Cu accumulation was increased with Zn added in leaves, but no significant difference was observed in roots. In conclusion, the accumulations of Zn and Cu in roots and leaves of centella were dependent on Cu and Zn availabilities in the medium.