Mecanismos de defesa contra herbivoria em espécies vegetais do cerrado: o papel do silício, nectários extraflorais e látex

• Ano de defesa: 2004
• Autor(a) principal: Oliveira, Flávio Rodrigues
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; Brasil; Programa de Pós-graduação em Ecologia e Conservação de Recursos Naturais
• Palavras-chave em Português: Ecossistema; Silício; Nectários; Látex; Concentração de silício foliar; Defesa biótica; Savana brasileira; Foliar silicon content; Biotic defenses; Brazilian savannah; CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA; Ecossistemas; Cerrados
• Link de acesso: https://repositorio.ufu.br/handle/123456789/30309; http://doi.org/10.14393/ufu.di.2004.88

Defensive mechanisms in plant species have been received great attention in ecological studies. However, low importance is giving to Silicon as a defensive agent in plants. In the present study we investigated defensive strategies against herbivory in Brazilian Savannah, related to Chemical defenses (foliar Silicon content) and the presence or absence of biotic defenses (extrafloral nectaries, EFNs). We sampled 15 tree species were sampled (ffve with NEFs and 10 without these glands) and investigated Silicon content in the tissue and foliar herbivory. The results suggested that Silicon is an effective agent to reduce herbivores action of in such species that accumulate this element. Plants bearing EFNs do not accumulate Silicon however, the presence of these EFNs constitutes an efficient defense against herbivory in the Brazilian Savannah. We suggest that the plants do not use only one defensive mechanism, all the time and we can not to point one as more effective in relation to the others. The selection for the defensive mechanism is subject of specifíc ecological pressures, not being able to one to say, therefore, that one choice is superior or more advantageous than other.