Silício na amenização da fitotoxicidade de cádmio e arsênio avaliada por fluorescência da clorofila

Detalhes bibliográficos
Ano de defesa: 2013
Autor(a) principal: SILVA, Airon José da lattes
Orientador(a): NASCIMENTO, Clístenes Williams Araújo do
Banca de defesa: GOUVEIA NETO, Artur da Silva, SOUZA, Edivan Rodrigues de, MELO, Évio Eduardo Chaves de, CUNHA, Karina Patrícia Vieira da
Tipo de documento: Tese
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal Rural de Pernambuco
Programa de Pós-Graduação: Programa de Pós-Graduação em Ciência do Solo
Departamento: Departamento de Agronomia
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4955
Resumo: Cadmium and arsenic are elements that are commonly associated with contamination and / or environmental pollution, besides offering risk to human health. Silicon has excelled in alleviating stress caused by toxic elements in plants. The technical analysis of phytotoxicity by chlorophyll fluorescence is a tool that has proven to be very promising in monitoring and detection of stress. The aim of this study was to investigate the effects of silicon in alleviating the stress caused by cadmium and arsenic in maize plants grown in nutrient solution and evaluate the potential of emission spectral parameters and the ratio Fr/FFr, besides determining the toxic dose of cadmium and arsenic in maize plants grown in nutrient solution. For that were mounted four experiments in nutrient solution with increasing doses of cadmium and arsenic, and nutrient solution contaminated with toxic doses of cadmium (30 mmol L-1) and arsenic (68 mmol L-1) and six increasing doses of Si ( 0; 0,25; 0,5; 1; 1;5 and 2 mmol L-1), were evaluated for the production of dry matter levels of cadmium, arsenic, silicon and photosynthetic pigments. Chlorophyll fluorescence measurements were made during the cultivation. Silicon promotes positive effects in alleviating the stress caused by cadmium and arsenic in maize plants as evidenced by the increase of photosynthetic pigments, and the reduction in the translocation of this element to the shoot, each cadmium and arsenic, respectively. The application of silicon resulted in higher levels of As in plant tissue and its use in studies of techniques for phytoremediation of contaminated soils may be promising. The analysis of chlorophyll fluorescence proved to be a sensitive tool to detect early toxicity caused by cadmium and arsenic in maize plants and can also be used successfully in the study of the effects amenizantes silicon in plant protection, the ratio Fr/FFr recommended in the variable identifying temporal changes in plants.