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Dissertação
Caracterização morfológica, molecular e controle alternativo da ferrugem da teca (Olivea neotectonae) com óleos essenciais
The area planted with teak (Tectona grandis L.f) has increased in Brazil and in recent years in the state of Tocantins. However, research related to phytosanitary problems of the species have not yet been developed, especially for the fungus Olivea neotectonae causal agent of rust teak, one of...
Autor principal: | Osorio, Pedro Raymundo Argüelles |
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Grau: | Dissertação |
Idioma: | pt_BR |
Publicado em: |
Universidade Federal do Tocantins
2017
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Assuntos: | |
Acesso em linha: |
http://hdl.handle.net/11612/310 |
Resumo: |
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The area planted with teak (Tectona grandis L.f) has
increased in Brazil and in recent years in the state of
Tocantins. However, research related to phytosanitary
problems of the species have not yet been developed,
especially for the fungus Olivea neotectonae causal agent
of rust teak, one of the fungal diseases of major economic
importance in this forest species. Given this fact, the work
was developed with the following objectives: In Chapter I,
the morphological and molecular characterization of O.
neotectonae, causal agent of teak rust was conducted. To
this end, teak sheets featuring yellow and powdery
pustules on the abaxial surface, characteristic of the teak
rust were collected in the municipalities of Gurupi and
Lagoa da Confusão in the state of Tocantins. In the
observation by an optical microscope, they were viewed
and measured fungal structures by scanning electron
microscopy was observed pathogen structures and the
penetration mode through the stomata. PCR amplification
of the ITS region of rDNA O. neotectonae using pairs of
primers ITS1-ITS4 was successful, obtaining a 600 bp
fragment. Direct sequencing of the PCR product from ITS O. neotectonae region, suggested it is a species belonging
to the family Chaconiaceae. Based on these results and of
morphology observed was confirmed O. neotectonae as
the causal agent of teak rust. In Chapter II, due to the
absence of fungicides registered for the control of this
disease in teak and the search for alternative methods of
disease control that are not harmful to the environment, to
evaluate the effect of the essential oils of lemongrass
(Cymbopogon citratus L.), citronella (Cymbopogon nardus
L.), mastruz (Chenopodium ambrosioides L.) and noni
(Morinda citrifolia L.) on germination urediniospores O.
neotectonae; assess the phytotoxic effect of these
essential oils in teak seedlings; and evaluate the use of
essential oils in control of the teak rust when applied
preventive and curative manner. It was found that
essential oils of noni and lemongrass inhibited 100%
germination of urediniospores. However, when applied to
plants at higher doses, the essential noni and lemongrass
oils phytotoxicity caused plants. The majority chemical
constituents were identified in the essential oil of
lemongrass leaves the geranial (41.46%) and neral
(32.43%), the grass citronella citronellal (30.07%) in
matruz the α- terpineol (41.97%) and essential oil extracted from mature noni fruit was octanoic acid
(64.03%). The preventive control was more effective in
controlling the disease than curative application, both for
lemongrass oil as for noni. When comparing the two oils in
the curative control were found lower values of the Area
Under the Rust Progress Curve when using the essential
oil of lemongrass. |