Copper translocation and tolerance in seedlings of tree species grown in contaminated soil/Translocacao e tolerancia de cobre em mudas de especies arboreas cultivadas em solo contaminado

High concentrations of copper (Cu) may be toxic to plants, yet some species can be tolerant to soils contaminated by this metal. The study aimed to evaluate Cu translocation and tolerance in seedlings of 'timbauva' (Enterolobium contortisiliquum (Vell.) Morong), 'patade-vaca' (Bauhinia forficata Link) and 'amendoim-bravo' (Pterogyne nitens Tul) subjected to Cu-contaminated soil. The study was conducted in a greenhouse for 120 days, using as substrate a clayey Oxisol. The experiment was set in a completely randomized design, using a 3 x 6 factorial scheme, corresponding to three forest species ('timbauva, 'pata-de-vaca' and 'amendoim-bravo') and six Cu doses in the soil (0, 60, 120, 180, 240 and 300 mg [kg.sup.-1]), with six replicates. The following variables were analysed: total dry matter, Cu content and its accumulation in roots and shoots, tolerance and translocation indices and the coefficient of impact of the contamination on the relative contents of Cu in roots and shoots. 'Timbauva' showed lower reduction in total dry matter with the increase of Cu doses in the soil, proving to be able to decrease Cu translocation to the shoots and tolerate doses of up to 236 mg [kg.sup.-1] of this metal in the soil. 'Timbauva' seedlings are more tolerant to contamination of Cu in soil, compared with seedlings of 'amendoim-bravo' and 'pata-de-vaca'. Key words: heavy metal phytoremediation reforestation soil cover Concentracoes elevadas de cobre (Cu) podem ser toxicas as plantas; contudo, algumas especies podem ser tolerantes a solo contaminado por este metal. Objetivou-se avaliar, no trabalho, a translocacao e a tolerancia de Cu em mudas de timbauva, pata-de-vaca e amendoim-bravo submetidos a solo contaminado com o referido metal. O trabalho foi conduzido em casa de vegetacao por 120 dias utilizando-se, como substrato, um Latossolo Vermelho com textura argilosa. O delineamento experimental foi inteiramente casualizado em arranjo fatorial (3 x 6), sendo tres especies florestais (timbauva, pata-de-vaca e amendoim-bravo) e seis doses de Cu no solo (0, 60, 120, 180, 240 e 300 mg [kg.sup.-1]), com seis repeticoes. Foram avaliados a massa seca total, os teores e a quantidade acumulada de Cu no sistema radicular e, na parte aerea, indice de tolerancia, indice de translocacao e o coeficiente de impacto no teor relativo. A timbauva evidenciou menor reducao da massa seca total com a elevacao das doses de cobre no solo indicando ser uma especie capaz de diminuir a translocaca