Biologia Vegetal

URI Permanente desta comunidade

http://repositorio.ufes.br/handle/10/17503
Programa de Pós-Graduação em Biologia Vegetal

Centro: CCHN
Telefone: (27) 4009 2588
URL do programa: http://www.biologiavegetal.ufes.br/

Navegar

Navegando Biologia Vegetal por Autor "Alves, Fernanda Brêda"

Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura disponível
    Item
    Aspectos ecofisiológicos das cianobactérias em uma lagoa costeira urbana (Lagoa Juara, Serra, ES)
    (Universidade Federal do Espírito Santo, 2015-02-24) Alves, Fernanda Brêda; Fernandes, Valéria de Oliveira; Dias Júnior, Camilo; Suzuki, Marina Satika
    This study aimed to evaluate the cyanobacterial community structure analyzing taxonomic richness, composition, total density (individuals / mL), abundance, dominance of species beyond their biomass in Juara pond in spatial scale, vertical and temporal. Two samples were performed, one in the dry season (Sept / 2013) and another held in the rainy season (Mar / 2014) at three sampling stations located in a longitudinal gradient in the lagoon, representing regions near the mouth of streams (including those backers of matter organic resulting from domestic effluent discharge "in natura" is primarily via stream Laranjeiras), the sea andthe deployment area of the cages. Sub-surface samples were collected at depths of 50% brightness 1% light water column, always in the morning. Qualitative samples were collected with a plankton net of 20 microns and quantitative bottle with van Dorn. The cyanobacterial community structure was evaluated based on its key attributes: taxa richness, total density, abundance and dominance. The biovolume was calculated based on geometric shapes approximating the shape of the cell. Were determined: temperature (air / water), euphotic zone depth, pH, dissolved oxygen (DO), turbidity, electrical conductivity (EC) and major nutrients (silicate, nitrate, ammonia nitrogen, total nitrogen, orthophosphate, total phosphorus). We recorded 43 species of cyanobacteria, belonging to 17 genera, 8 families and 4 orders, 3 genres confirmed in literature as microcystin producers. The total density of cyanobacteria showed higher values in samples influenced by precipitation with no differences between the EA1 and EA2 station, just sampling station AE3 significant difference between the period of drought and rain, with higher density figures in the dry season. The biovolume data were higher in the rainy season and EA2 sampling station. The vertical variation of biovolume showed a significant difference only in the sampling stations EA1 and EA3, with uniform EA2 station at different depths. So the Microcystis genus had a higher contribution in terms of biovolume. The microcystin produced mainly by this genre was present in the aquatic environment, both in the dry season as in the rainy, with values within the parameters allowed by law. The values of total phosphorus, total nitrogen and nitrate showed temporal and spatial variation. The vertical variation was slight in the depths of the three sampling stations. The highest recorded concentrations of orthophosphate, total phosphorus, total nitrogen and nitrate, especially in EA2 and EA3 stations. The EA2 and EA3 stations showed limnological and biological characteristics of similarity. Both stations suffer human impact due to intensive fish farming system and through the discharge of domestic sewage "in natura" via stream Laranjeiras respectively. The Juara pond has multiple uses, and the development of subsistence activity as intensive fish farming, this practice together with the impacts associated with the injection of wastewater, showed signs of changes regarding the environmental conditions in the pond leading to the development of species-producing cyanobacteria microcystin. The presence of this toxin at high levels may impair the use of the pond, especially intensive farming of fish for consumption and leisure and recreation.
  • Nenhuma Miniatura disponível
    Item
    Potencial bioestimulante do extrato de microalgas na germinação e crescimento de culturas agrícolas
    (Universidade Federal do Espírito Santo, 2022-10-05) Santos, Nair Hildelgard Soares dos; Machado, Levi Pompermayer; https://orcid.org/; http://lattes.cnpq.br/; Co-orientador2; https://orcid.org/; http://lattes.cnpq.br/; Co-orientador3; https://orcid.org/; http://lattes.cnpq.br/; Co-orientador4; ID do co-orientador4; Lattes do co-orientador4; Fernandes, Valéria de Oliveira ; https://orcid.org/; http://lattes.cnpq.br/; Orientador2; https://orcid.org/; http://lattes.cnpq.br/; https://orcid.org/; http://lattes.cnpq.br/; Corte, Viviana Borges ; https://orcid.org/; http://lattes.cnpq.br/; Almeida, Stéfano Zorzal de ; https://orcid.org/; http://lattes.cnpq.br/; Alves, Fernanda Brêda ; https://orcid.org/; http://lattes.cnpq.br/; Dutra, Jean Carlos Vencioneck ; http://lattes.cnpq.br/; 5º membro da banca; https://orcid.org/; http://lattes.cnpq.br/; 6º membro da banca; https://orcid.org/; http://lattes.cnpq.br/; 7º membro da banca; https://orcid.org/; http://lattes.cnpq.br/
    Currently the global demographic pressure on agricultural production requires new and sustainable approaches to meet the growing demand for plant biomass for human feed, animal feed and energy production. Therefore, there has been growing interest in natural biostimulant substances in agriculture due to the challenge of balancing technological development with environmental conservation. Microalgae have several biotechnological applications, including biostimulants. In modern agriculture, microalgae are an ecologically correct option to replace chemical fertilizers, as they can be used as biostimulants, soil modifiers and food additives. The objective of this work was to evaluate the effects of the application of microalgae extracts on the germination and growth of bean (Phaseolus vulgaris L.), corn (Zea mays L.) and papaya (Carica papaya L.) crops. It was possible to evidence that aqueous extracts obtained from microalgae presented biostimulating growth potential, considering that all seeds used in this study showed positive germ responses. It is noteworthy that most seeds obtained higher germination values, mean time, good speed indices, and better initial performance when submitted to extracts of species of the genus Chlorella, mainly at concentrations 1.0 g/L and 1.5 g/L. For the growth experiment, Scenedesmus acuminatus extract showed efficacy in stimulating the growth of bean plants, considering that plants submitted to this extract obtained higher grain yield per plant and higher number of pods. Thus, it can be affirmed that the biostimulant, when applied by foliar, is capable of promoting the transport of photoassimilates for the seeds, which would result in greater accumulation of mass in the seeds. It is also possible to attribute the positive effect of S. acuminatus extract on the yield and productivity of the bean crop to the availability of micronutrients present in this microalgae. It is necessary to highlight that to evaluate the action of extracts produced from algae, one should consider the agricultural crop to be tested, and concentrations. Because the seeds may present a different physiology and this influences the mechanism of action of the extracts, consequently presenting different responses from those obtained in this study. From the results it is possible to attribute the importance of microalgae in the agricultural sector, for its potential for the development of new biostimulating products of plant growth