Peat influence on Zn tolerance, bioconcentration and bioaccumulation in Eucalyptus grandis Hill ex Maiden

摘要

Soil contamination with zinc occurs in mining and agricultural areas through successive applications of pig slurry. Essential to the selection and adaptation of plants to contaminated soil, is the study of species showing not only tolerance but also bioaccumulation or bioconcentration of zinc associated with amelioration. In this context, this study aimed to evaluate the influence of peat addition on the tolerance, bioconcentration and bioaccumulation of Zn in Eucalyptus grandis seedlings. A completely randomized experimental design was used, in a factorial arrangement (2 x 6), with and without the addition of peat (200 mL L-1 soil) and six doses of Zn (zero, 200, 400, 600, 800 and 1000 mg kg-1) with 15 replications, conducted for 120 days. The height, stem diameter, root and shoot dry weight, concentration and Zn content in the root system and aerial parts, indices of tolerance and translocation, and bioaccumulation factors and bioconcentration were evaluated. The addition of 200 mL L-1 of peat provided increased tolerance and a stimulating effect on morphological parameters of E. grandis seedlings. This species, however, did not concentrate zinc to the extent that it could be considered a bioaccumulating plant.