Crescimento, distribuição e acúmulo de cobre e zinco em plantas de pinhão-manso

Abstract

Resumo -Pesquisas referentes à extração de metais pesados por planta de pinhão-manso ainda são incipientes. Com a perspectiva dessa planta ser utilizada na recuperação de solos contaminados, objetivou-se, com este trabalho, avaliar os efeitos do cobre e zinco no crescimento do pinhão-manso e o acúmulo e distribuição desses metais na planta. Dois experimentos foram realizados em delineamentos inteiramente casualizados: no primeiro, os tratamentos consistiram em cinco doses de cobre (0; 25; 50; 75 e 100 mg dm -3 ) e, no segundo, quatro doses de zinco (0; 50; 100 e 150 mg dm -3 ), com três repetições. Aos 50; 70; 90 e 110 dias após o semeio, foram avaliados: altura da planta, diâmetro caulinar e área foliar. No final do experimento as plantas foram colhidas e avaliados os teores de cobre e zinco nos tecidos vegetais. Amostras de solo de cada vaso foram coletadas e submetidas às analises químicas. As plantas de pinhão-manso, durante o período experimental, são tolerantes aos tratamentos utilizados, no entanto, doses de cobre e zinco no solo acima de 75 e 50 mg dm Abstract -Researches concerning the extraction of heavy metals by Jatropha curcas L. plants are still preliminary and incomplete. With the prospect of this plant to be used in phytoremediation of polluted soils, this study aimed to evaluate the effect of copper and zinc in the initial development of Jatropha curcas L. and accumulation and distribution of these elements in this plant. Two experiments were carried out in design completely randomized with three replications; the first one with five copper (0; 25; 50; 75; 100 mg dm -3 ) and the second with four zinc (0; 50; 100; 150 mg dm -3 ) treatments. At 50; 70; 90 and 110 DAS, were evaluated: plant height, stem diameter and leaf area. At the end of the experiment the plants were harvested and assessed the levels of copper and zinc in plant tissues. Soil samples were collected from each pot and subjected to chemical analysis. The Jatropha curcas L plants, during the experimental period are tolerant to the treatments, however, copper and zinc levels in soil above 75 and 50 mg dm -3 , respectively, affect their growth. The copper and zinc concentrations in the plants were ranked in the following order, respectively: leaf > roots > stem; stem > leaf > root. Zinc translocation was higher than copper in the plants.

Copper translocation and tolerance in seedlings of tree species grown in contaminated soil

“…Chaves et al (2010) also observed a reduction in ITRA with the increase of Cu in the soil in seedlings of castor bean (Ricinus communis L.). This occurs because Cu is strongly bound to root cell walls and is not readily available in the plant (Kabata-Pendias, 2011).…”

“…Plants with higher accumulation of metals in the root system, compared with the shoots, are classified as tolerant to the absorption of metals (Garbisu & Alkorta, 2001), since the capacity to limit the translocation to the shoots is one of the mechanisms through which the root system can contribute to the tolerance of some plant species to heavy metals (Chaves et al, 2010). In this case, 'timbaúva' may have higher ability to accumulate Cu in the root system than the other tested species.…”

Photosynthesis rate, chlorophyll content and initial development of physic nut without micronutrient fertilization

“…In Brazil, the majority of studies on physic nut (shrub or small tree) have evaluated the effect of macronutrients (Lima et al, 2011;Souza et al, 2011;Balota et al, 2012), and only a few addressed the adequate levels of micronutrients (Chaves et al, 2010). Besides, the published studies evaluated the nutritional state only by leaf diagnosis and visual observation (Silva et al, 2009;Maia et al, 2011).…”

Consumo Hídrico De Calla Lily Submetida Ao Manejo De Irrigação via Solo E Teores De Cobre1

“…Plantas com estas características podem facilitar o processo natural de transferência e de distribuição do Cu nos componentes do ecossistema, através da sua ciclagem biogeoquímica (CHAVES et al, 2010;CAIRES et al, 2011;MARQUES;AGUIAR;SILVA, 2011). Deste modo, apesar das plantas de calla lily apresentarem baixos índices dos fatores de FT e FCO, estes indicam um potencial de fitoacumulação de cobre, sobretudo, em tubérculo, por consequência tolerante a altos teores deste elemento no solo.…”