Doutorado em Biologia Vegetal

URI Permanente para esta coleção

http://repositorio.ufes.br/handle/10/17505

Nível: Doutorado
Ano de início: 2013
Conceito atual na CAPES: 4
Ato normativo: Homologado pelo CNE (Portaria MEC Nº 609, de 14/03/2019. Publicação no DOU 18 de março de 2019, seç. 1, p.63 - Parecer CNE/CES nº 14/03/2019, Processo no 23001.000335/2018-51).
Periodicidade de seleção: Anual
Url do curso: https://biologiavegetal.ufes.br/pt-br/pos-graduacao/PPGBV/detalhes-do-curso?id=99

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Navegando Doutorado em Biologia Vegetal por Assunto "Abiotic stress"

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    Efeitos do evento sobre características estruturais, fisiológicas e bioquímica de mudas de Theobroma cacao L. (Malvaceae) e uso do silício como amenizador do estresse
    (Universidade Federal do Espírito Santo, 2018-08-07) Fantinato, Dayana Effgen; Milanez, Camilla Rozindo Dias; Corte, Viviana Borges; Matsumoto, Silvia Tamie; Aquije, Glória Maria de Farias Viégas; Souza, Carlos Alberto Spaggiari de
    The cacao tree (Theobroma cacao) is a perennial species, of arboreal origin originating in the Upper Amazon region. The economic importance of this species is mainly related to its seeds, which are used for the manufacture of chocolate. Within the national scenario, Espírito Santo occupies the 3th position as the largest producer, and most of this production is in the municipality of Linhares. In Espírito Santo, the cultivation of cacao began to be full sun. In this condition, the plants are more exposed to the action of winds. It is known that wind is characterized as an environmental variable that interferes with plant growth, however, little is known about its effects on the anatomical, physiological and biochemical characteristics of cacao. In an attempt to ameliorate abiotic stresses, silicate fertilization has shown promise with positive effects on growth, gas exchange and biochemical defenses. In this context, the objective of the present work was to evaluate the influence of the wind through the analysis of gas exchange, the morphoanatomic characteristics, the contents of structural carbohydrates and lignin on cocoa seedlings. From the results, the effects of a possible action of the silicon in the improvement of the behavior of the cacao tree in the face of the stress caused by wind were evaluated. For this, in a first experiment, seedlings grafted with the genotype PS-1319 of T. cacao were used in two areas, one being open, more exposed to the wind and another one consorted with banana trees, with lower wind incidence. Monthly growth analyzes were performed on these plants for 12 months and at the end of this period, leaf anatomy, gas exchange and the content of structural carbohydrates and lignin were evaluated. In the second experiment, seedlings of the same genotype were grown in nurseries and submitted to silicon treatments, applied to the leaf and soil, at concentrations of 2 mM and 1 mM, respectively. Later, the seedlings were submitted to a wind source with an average velocity of 2.25 m / s, from 11 am to 6 pm, for 28 days. At the end of the experiment, growth analysis, foliar anatomy, foliar and lignin carbohydrate content, gas exchange and biochemical analysis were performed. The results showed that the plants of the open area had higher density, stomatal conductance and greater photosynthesis. Anatomically, the leaves were thicker, presenting larger palisade and spongy parenchyma, greater abaxial and adaxial epidermis, besides a larger central vein and hemicellulose and lignin contents. However, there was a reduction in growth. The evaluation of the effects of silicon on the plants subjected to the wind showed that the silicate fertilization had a positive effect, promoting greater robustness, higher values of area and stem diameter, stomatal density and leaf thickness with increase of the vein, adaxial epidermis and palisade parenchyma, improving the intrinsic efficiency of water use and lower transpiration, and having made the enzymatic activity efficient, providing energy savings
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    Efeitos dos ácidos múmicos extraídos de lodo de esgoto em Zea Mays L. sob restrição hídrica e estresse salino
    (Universidade Federal do Espírito Santo, 2018-03-16) Rocha, Lívia Dorsch; Matsumoto, Silvia Tamie; Falqueto, Antelmo Ralph; Milanez, Camila Dias; Morales, Dania Elisa Christofoletti Mazzeo; Dobbss, Leonardo Barros
    The lack of disposal of solid waste generated by sewage sludge treatment has motivated research in the area of cycling of these materials. One of the alternatives that has been investigated is an extraction of chemical substances and / or their bioactive fractions. Humic acid is one of the fractions most investigated due to its high interactivity with the vegetable promoting its growth through the biochemical development. It is also known that abiotic stress caused by water deficiency compromises the physiological plant development as well as its growth. (HA-LE- 2.0 mM C L-1 ) in maize seedlings stressed by NaCl- 100 mM (saline stress) and PEG 6000 (water restriction) by integrating elemental, physiological, biochemical, toxicogenic and of plant growth, seeking to evaluate the potential benefits / risks of using this biostimulant. A solution for the application of humic acid from sewage sludge was performed with hydroponics in maize seedlings with water restriction (PEG 6000 + NaCl) with application of acid (2.0 mM C L-1 ). Results of the quantification of the elements C, H, N and O on HA-LE indicated it as a source of nutrients for the plants due to the availability of these elements. Photosynthesis rates, such as carbon assimilation, transpiration and conductance, are shown to be attenuated in treatments with the addition of humic acid, both in saline stress and in water deficit. Growth rates corroborated with photosynthesis results indicating lower biomass loss of plant organs and higher root growth when related to treatments with humic acid under stress. In addition, biochemical antioxidant markers (SOD, APX) ratified the biochemical potential of HA-LE in increasing the defense of plants under water deficiency against reactive oxygen species. It was also observed higher activity of enzymes bound to plasma membrane permeability such as H+ -ATPases in treatments with humic material confirming this intrinsic characteristic. Another biochemical indicator of abiotic stress was the accumulation of the amino acid proline that was shown to be more efficient in stress plants with HA-LE addition. These plants are successful in LPP and electrolyte leakage and are less affected by their effects. In addition, a toxicogenic analysis did not indicate cytotoxic, genotoxic and mutagenic potentials in the treatments, thus evidencing greater safety with the use of AH-LE alection cell. Considering these results, it is possible to suggest a use of humic acid in plants stressed by water restriction as a remedy of the effects caused by water deficiency.