Potencial fitorremediador de Brachiaria arrecta : modificações nas características anatômicas e fisiológicas na presença de arsênio e cádmio
Toxic elements are deposited in the environment by human activities in increasing amounts. Techniques for the removal of these, such as phytoremediation, require knowledge of different species tolerant to these elements. This study had as objective to evaluate the leaf and root anatomical features,...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2011 |
| País: | Brasil |
| Institución: | Universidade Federal de Lavras (UFLA) |
| Repositorio: | Repositório Institucional da UFLA |
| Idioma: | portugués |
| OAI Identifier: | oai:repositorio.ufla.br:1/3191 |
| Acceso en línea: | https://repositorio.ufla.br/handle/1/3191 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciências Agrárias Brachiaria arrecta Fitorremediação Cádmio Arsênio Phytoremediation Cadmium Arsenic |
| Sumario: | Toxic elements are deposited in the environment by human activities in increasing amounts. Techniques for the removal of these, such as phytoremediation, require knowledge of different species tolerant to these elements. This study had as objective to evaluate the leaf and root anatomical features, the characteristics of gas exchange, growth and development and to achieve quantification of DNA in plants of Brachiaria arrecta under different concentrations of arsenic (As) and cadmium (Cd), aiming at the detection mechanisms that provide tolerance of this species to these pollutants, providing an indication of this species in phytoremediation programs effluent contaminated by these heavy metals. The plants of B. arrecta were grown in a greenhouse for 60 days for clonal reproduction. The clones were grown in Hoagland nutrient solution containing arsenic and cadmium in concentrations of 0,0; 0,25; 0,50; 1,0; 2,0 and 4,0 mg L-1 of As and 0,0; 0,4; 0,8; 1,6; 3,2 and 6,4 mg L-1 of Cd. After 21 days of the experiment leaves were collected from plants for their anatomical analysis, DNA quantification and analysis of growth. The tests for the amount of DNA were performed on the 18th day after the experiment. The experimental was completely randomized design with six replicates. The data were subjected to analysis of variance and the Scott-Knott test with p <0.05. Due the plant to have anatomical and physiological plasticity by the changes induced to the environment, the species B. arrecta demonstrated potential for application in bioremediation programs of environments contaminated with As, due the tolerance to this contaminant. For symptoms of toxicity at the highest concentrations of Cd tested, the species can be considered as bioindicators of pollution by Cd. It also has plasticity by means of anatomical changes, and less sensitivity in higher concentrations of Cd tested, but not sufficient to cause senescence and death of plants. The species B. arrecta shows potential for application programs to extract Cd from aquatic environments. |
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