Accumulation and translocation of zinc in seedlings of species from genera Eucalyptus and Corymbia/Acumulacao e translocacao de zinco em mudas de especies do genero Eucalyptus e Corymbia

The zinc accumulation and compartmentalization are distinct among forest species. The objective of this study was to evaluate the ability of zinc accumulation and translocation in seedlings of Eucalyptus and Corymbia in soil contaminated with zinc. The experiment was conducted during October 2011 and March 2012, in a greenhouse, in a completely randomized design, in factorial arrangement (4 x 8), with 12 replicates. Four species were used: Eucalyptus. grandis W. Hill ex Maid., Eucalyptus. saligna Smith, Eucalyptus. dunnii Maiden and Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson, and eight doses (0, 140, 280, 420, 560, 700, 840 and 980 mg of Zn [kg.sup.-1] of soil). The seedlings of forest species showed different behavior relative to zinc doses applied in the soil, reducing the dry mass of aerial parts. The E. dunnii presents higher reduction in plant height, root volume, leaf area and root dry mass than other species. The C. citriodora has higher zinc accumulation in aerial parts as well as translocation index, and has low coefficient of impact of relative content with doses applied on the soil, indicating tolerance in contaminated soils. Key words: eucalyptus contaminated soil heavy metal zinc absorption O acumulo e a compartimentalizacao de zinco sao distintos entre as especies florestais. O objetivo do trabalho foi, portanto, avaliar a capacidade de acumulacao e de translocacao de zinco em mudas de Eucalyptus e Corymbia em solo contaminado com zinco. O experimento foi conduzido no periodo de outubro de 2011 a marco de 2012, em casa de vegetacao, em delineamento experimental inteiramente casualizado, com arranjo fatorial (4 x 8), com doze repeticoes. Foram utilizadas quatro especies: Eucalyptus. grandis W Hill ex Maid., Eucalyptus. saligna Smith, Eucalyptus. dunnii Maiden e Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson, e oito doses de zinco (0, 140, 280, 420, 560, 700, 840 e 980 mg [kg.sup.-1] de solo). As mudas das especies florestais mostraram comportamento diferenciado em relacao as doses de zinco aplicadas no solo com reducao na massa seca da parte aerea. O E. dunnii apresenta maior reducao na altura de planta, volume radicular, area foliar e massa seca radicular em relacao as demais especies. O C. citriodora apresenta maior acumulacao de zinco na parte aerea e indice de translocacao e baixo coeficiente de impacto do teor relativo com as doses aplicadas no solo, indicando tolerancia em solos contaminados. Palavras-chave: eucalipto