Bioavailability of Zinc in Selected Plants and Their Associated Soils of Tirumala Region

Soil samples and plant organs from three native plant species, Datura metel L. , Teprosia purpurea L. and Amaranthus viridis L. were collected from seshachalam forest of tirumala in order to determine the total and bioavailable zinc concentrations in soils and to assess the bioconcentration factor (BCF) and transport index (Ti) of zinc in the plants. Total zinc concentrations in soils (pH 7.3-8.7) where D. metel L. , T. purpurea L. and A. viridis L. were collected, reached levels considered to be contaminated (162.7622.13, 241.8169. and 203.74 54.4 g/g respectively). Bioavailable zinc ranged from 1.2 to5.2 g/g. In the three plant species, zinc concentrations in leaves were significantly higher than in roots and stem. D. metel L. showed the highest concentration in its leaves (35.928.2) and higher values of BCF (0.2) and Ti (1.9), indicating that this species has a greater capacity to accumulate and translocate the metalloid to the leaf than do the other species.