Avaliação de isolados de Trichoderma spp. para controle de Phytophthora nicotianae

Detalhes bibliográficos
Ano de defesa: 2015
Autor(a) principal: Melo, Jaila Ferreira [UNESP]
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Estadual Paulista (Unesp)
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://hdl.handle.net/11449/132431
Resumo: Orange crops in the Brazil are affected by various diseases such as gummosis caused by Phytophtora nicotianae Breda de Haan (synonymous whit P. parasítica Dast.), which is controlled by chemical fungicides. However, the high costs and environmental problems caused by the intensive use of these fungicides have led to the search for alternative methods of control. The objective of this study was to evaluate the antagonistic activity of 50 Trichoderma spp. isolates against P. nicotianae by the production of antimicrobial compounds and an alfalfa seedling bioassay. The paired culture showed that all isolates tested inhibited the mycelial growth of the pathogen. In the production of antimicrobial compounds, 41 isolates produced volatile compounds using dextrose as carbon source; however, further assays showed that the use of sucrose or maltose as carbon source increases the production of these compounds. Seven isolates of Trichoderma spp. produced thermostable compounds and 14 isolates produced cell-free culture antimicrobial compounds of the antagonist. In the alfalfa seedling bioassay, four isolates of Trichoderma spp. inhibited the formation of sporangia and mycelia growth. The evaluation in vitro concerning to the antimicrobial compound production by the Trichoderma spp. isolates and the alfalfa seedling bioassay both were able to select biocontrol agents to control of P. nicotianae. The Trichoderma spp. isolates, TB12, TB14, TB28, and TB30 presented the best disease control.