Avaliação da absorção de zinco por Ocimum basilicum L. em latossolo vermelho

Abstract

The objective of this work was to verify the absorption of zinc by Ocimum basilicum L., known as basil, in contaminated red latosol. The seedlings were prepared from the cataloged seed planting until they reached 10 cm in height for transplantation in 2kg pots of prolipropylene. Increasing concentrations of zinc were applied to the soil in quintuplicate, and no zinc was added to the soil (control). Zinc concentrations were defined from the maximum capacity of the soil to adsorb the metal in its particles, and the following concentrations were established: 0.0 mg kg-1, 120.5 mg kg-1, 160.7 mg kg-1 , 241.0 mg kg-1, 482.0 mg kg-1, 964.0 mg kg-1, 1928.0 mg kg-1 and 3856.0 mg kg-1 zinc. Each pot received one seedling of Ocimum basilicum L., totaling forty pots. The plants were placed in the pots with zinc for ninety days and after that time they were removed, washed and separated in stem, leaf and root, submitted to the greenhouse and crushed with a knife mill, passed through an opening sieve <70 µm and treated with acid digestion. The samples were then analyzed by flame atomization atomic absorption spectrometry (FAAS) for zinc determination. The part of the plant that most absorbed metal was the leaf (2945.2 mg kg -1), followed by the root (890.8 mg kg -1) and stem (420.7 mg kg -1). Bioaccumulation and translocation factors and metal absorption rate (MER) were calculated to assess the presence of metal in plant parts. Data were submitted to analysis of variance, canonical discriminant analysis and Tukey test (5%). All calculated values of bioaccumulation and translocation factors were greater than one (1), indicating that the plant can be considered phytoextractor and that translocation of this metal to the shoots occurs, with metal absorption rate with a minimum time of 5.6. years.