• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 4
  • Tagged with
  • 12
  • 12
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Výskyt farmak v životním prostředí I. / The occurence of pharmaceuticals in the environment I.

Tkáčová, Gabriela January 2018 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: Gabriela Tkáčová Supervisor: RNDr. Jitka Vytlačilová, Ph.D Title of diploma thesis: The occurence of pharmaceuticals in the environment I. Drugs are biologically active substances used for treatment and prophylaxis of human and animal illnesses. Some drugs, however, remain biologically active even after they are excreted from the organism. By various means these substances can appear in the environment and can be detected in wastewater, surface water, seawater, groundwater, drinking water, sediments and soil. Chronic presence of low concentrations of drugs in the environment can negatively affect non-target organisms. Aim of this diploma thesis is to study presence of SSRI, statins and hypoglycemic drugs in the environment. Drugs from these farmacodynamic groups were detected in the environment in concentrations ranging from ng/l to μg/l. Selected drugs from SSRI group were fluoxetine, citalopram, fluvoxamine, sertraline, paroxetine and escitalopram. In water samples they were detected in concentration ranging from tens to hundreds ng/l, they were also detected in soils and sediments. Toxicity for water biota was also proven. Fluoxetine caused changes in secondary sexual characteristics of fish...
2

Fate and transport of Cry1Ab from transgenic Bacillus thuringiensis corn in an agricultural field and aquatic microcosms

Strain, Katherine E. 01 December 2014 (has links)
AN ABSTRACT OF THE THESIS OF Katherine E. Strain, for the Master's degree in Zoology, presented on October 21, 2014, at Southern Illinois University Carbondale. TITLE: FATE AND TRANSPORT OF CRY1AB FROM TRANSGENIC BACILLUS THURINGIENSIS CORN IN AN AGRICULTURAL FIELD AND AQUATIC MICROCOSMS MAJOR PROFESSOR: Dr. Michael Lydy, Ph.D. Genetically-modified crops expressing insecticidal crystalline proteins derived from a soil bacterium, Bacillus thuringiensis (Bt), were commercialized almost two decades ago as a means to combat agricultural pests. The Bt proteins are highly specific and only lethal upon ingestion, limiting the scope of toxicity to target insects. However, evidence for risk to non-target organisms and negative public perceptions on the use of Bt crops has caused controversy surrounding their use. The objective of this research was to monitor the fate and transport of a Bt protein, Cry1Ab, in a large-scale agricultural field and in aquatic microcosms. Quantitative methods were validated using enzyme-linked immunosorbent assay (ELISA) and then used to evaluate field and laboratory samples. The highest environmental concentrations of the Cry1Ab protein were found in runoff water and sediment, up to 130 ng/L and 143 ng/g dry weight, respectively, with the Cry1Ab protein detected in both Bt and non-Bt fields. As surface runoff and residual crop debris can transport Bt proteins to waterways adjacent to agricultural fields, a series of laboratory experiments were conducted to determine the potential risk to non-target aquatic organisms. The results showed that sediment type and temperature can influence the degradation of the Cry1Ab protein in an aquatic system and that the Cry1Ab protein can persist for two months. While Cry1Ab protein concentrations measured in the field soil indicate little risk to terrestrial organisms, the consistent input of Bt-contaminated runoff and crop debris into agricultural waterways impart chronic risk to non-target aquatic species.
3

Vliv geneticky modifikované kukuřice exprimující toxin Cry3Bb1 na necílové organizmy. / Impact of genetically modified maize expressing Cry3Bb1 toxin on the non-target organisms.

SVOBODOVÁ, Zdeňka January 2010 (has links)
Presented study compares impacts of the GM maize MON 88017 and the non-transgenic maize on the non-target invertebrates. The Diabrotica-resistant and herbicide-tolerant GM maize may become important for most of Europe as the spred of Diabrotica virgifera virgifera LeConte continues but its implementation has been hindered by fears of undesirable environmental effects. I confirmed that MON88017 expresses the insecticidal Cry3Bb1 toxin but I found no evidence of any negative impact on the monitored species. Both the composition and the species abundances of invertebrate communities were similar to those in the stands of the conventional non-transgenic maize varieties.
4

Výskyt farmak v životním prostředí II. / The occurence of pharmaceuticals in the environment II.

Olivová, Tereza January 2017 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Tereza Olivová Supervisor: RNDr. Jitka Vytlačilová, Ph.D Title of diploma thesis: The occurrence of pharmaceuticals in the environment II. Pharmaceuticals are biologically active substances used for treatment or prevention of human and animal diseases. Some of these substances remain active even after being excreted from an organism and they can enter the environment. The residues of pharmaceuticals are present not only in rivers, but also in sea, groundwater and in soil, into which the contaminated water and manure are applied. The concentration of pharmaceuticals in water and in soil differ from place to place (it is higher e. g. in close proximity of sewage treatment plants) and from season to season (it depends on levels of precipitations and sunshine). Nowadays, thanks to sensitive analytical methods it is not a problem to detect these xenobiotics even in very small amounts, in which they usually occur in nature (usually in order of units or tens of ng/l or ng/g). However, even these low concentrations might have a negative impact on the life of non-target organisms (e. g. reproduction disorders) and therefore, the calculations, which measure the lever of risk of particular...
5

Avaliação dos efeitos do fipronil (ingrediente ativo do FRONTLINE®) nos ovários de carrapatos Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) e no sangue periférico de roedores

Oliveira, Patrícia Rosa de [UNESP] 31 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-31Bitstream added on 2014-06-13T18:41:13Z : No. of bitstreams: 1 oliveira_pr_dr_rcla.pdf: 1096326 bytes, checksum: a2a1be84ec8b09cfcf7ab3110daa8ce4 (MD5) / O presente estudo avaliou os efeitos do fipronil em fêmeas semi-ingurgitadas de carrapatos Rhipicephalus sanguineus por meio do desenvolvimento de protocolo adequado de bioensaio in vitro (AIT), monitorado diariamente, com determinação da CL50 (concentração 50% letal) e intervalo de confiança a 95%, g (95): CL50 = 9.647 ppm (4.711 a 13.470), bem como analisou os efeitos histológicos e ultra estruturais deste produto nos ovários desses indivíduos, demonstrando quais são os mecanismos de defesa utilizados pelas células germinativas para eliminar o composto químico do sistema. Para o estudo morfológico, os carrapatos foram divididos em quatro grupos, onde o grupo I foi utilizado como controle e os grupos II, III e IV, foram submetidos às concentrações de 1, de 5 e de 10 ppm (CL50) de fipronil, respectivamente. As alterações variaram desde a presença de poucos e pequenos vacúolos até a interrupção da vitelogênese e morte celular. A concentração de 10 ppm de fipronil foi a que mais afetou o desenvolvimento dos ovócitos. Mecanismos de defesa celular como o aumento da quantidade e novo arranjo citoplasmático de elementos do citoesqueleto, bem como a grande quantidade de vacúolos digestivos e de figuras mielínicas foram observados. Simulando a ação do fipronil nos hospedeiros de carrapatos expostos aos acaricidas que tenham esse princípio ativo em sua composição, o presente estudo avaliou também o potencial citotóxico (danos causados nas células do fígado), genotóxico e mutagênico do fipronil utilizando camundongos submetidos a diferentes doses da droga. Os camundongos foram divididos em quatro grupos: grupo controle e grupos I, II e III, que foram expostos às doses de 15mg/Kg, 25 mg/Kg e 50 mg/Kg (DL50) de fipronil, respectivamente. Em seguida, o fígado dos indivíduos foi retirado, seccionado e analisado por meio de técnicas histológicas e histoquímicas... / The present study evaluated the effects of fipronil on semi-engorged females of the tick Rhipicephalus sanguineus. A protocol for an in vitro bioassay (AIT) was developed, and the LC50 (lethal concentration 50%) and 95% confidence interval were determined: LC50 = 9.647 ppm (4.711 to 13.470). Histological and ultrastructural alterations in ovaries were also examined to describe the defense mechanisms of germ cells to eliminate the chemical compound from the system. For the morphological analysis, ticks were divided into four groups. Group I was used as the control group and groups II, III,and IV were exposed to concentrations of 1, 5, and 10 ppm (LC50) of fipronil, respectively. Alterations varied from the presence of few and small vacuoles to the interruption of vitellogenesis and cell death. The concentration of 10 ppm of fipronil had the strongest effect on oocyte development. Defense mechanisms of cells were observed such as increase in the amount and changes in the arrangement in the cytoskeleton elements in the cytoplasm, amount of digestive vacuoles and myelin figures. Simulating the action of fipronil in tick hosts exposed to fipronil, the present study also assessed the cytotoxic (damage caused in liver cells), genotoxic, and mutagenic potential of fipronil in mice treated with different doses. Mice were divided into four groups: control group and groups I, II, and III, which were exposed to doses of 15mg/Kg, 25 mg/Kg, and 50 mg/Kg (LD50) de fipronil, respectively. The liver of mice were dissected, sectioned, and analyzed with histological and histochemical techniques. Changes varied from proliferation of Kupffer cells, hypertrophy of hepatocytes, accumulation and distribution of proteins, polysaccharides, lipids, and presence of vacuoles in the cytoplasm of hepatocytes, as well as the obstruction of blood vessels, characterizing mainly a) autophagic processes, b) steatosis... (Complete abstract click electronic access below)
6

Desenvolvimento de artr?podes n?o alvos e estresse fisiol?gico em algodoeiro geneticamente modificado expressando as prote?nas CRY1F e CRY1AC / Development of non-targeted arthropods and physiological stress in genetically modified cotton expressing CRY1F and CRY1AC proteins

Valadares, Nermy Ribeiro 17 February 2017 (has links)
?rea de concentra??o: Manejo integrado de pragas. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-07-24T19:32:10Z No. of bitstreams: 2 nermy_ribeiro_valadares.pdf: 721013 bytes, checksum: 6f53437940ebff37fcc6b98c4109987e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-07-28T18:01:04Z (GMT) No. of bitstreams: 2 nermy_ribeiro_valadares.pdf: 721013 bytes, checksum: 6f53437940ebff37fcc6b98c4109987e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-28T18:01:04Z (GMT). No. of bitstreams: 2 nermy_ribeiro_valadares.pdf: 721013 bytes, checksum: 6f53437940ebff37fcc6b98c4109987e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017 / O Brasil ? um dos maiores produtores mundiais de algod?o, n?o apenas em volume, mas tamb?m em qualidade e inova??o. Por?m, o ataque de insetos pragas ? um dos principais entraves para a produtividade das lavoras de algod?o, o que ? acentuado pelas grandes ?reas de monocultivo. Uma das t?ticas de manejo que est? sendo empregada ? a resist?ncia de plantas. A cultura hospeda diversos organismos, dentre eles um grande n?mero de artr?podes como o pulg?o Aphis gossypii Glover 1877 (Hemiptera: Aphididae) e o ?caro fit?fago Tetranychus ludeni zacher, 1913 (Acari: Tetranychidae), que se alimentam da parte a?rea das plantas, podendo causar preju?zos econ?micos. As variedades transg?nicas utilizadas no manejo de pragas s?o desenvolvidas para controlar determinado grupo de insetos, de acordo com a toxina que expressam. Por?m ao serem expressas continuamente, essas toxinas ficam expostas aos demais herb?voros que se hospedam na planta, surgindo uma preocupa??o de que o uso em larga escala desta tecnologia possa ter efeitos adversos sobre artr?podes n?o alvos. O impacto das prote?nas Bt em artr?podes n?o visados ? menos compreendido do que os seus efeitos nos organismos alvos, onde o mecanismo da a??o t?xica ? conhecido. H? pouca informa??o sobre efeitos de transg?nicos Bt sobre popula??es de pulg?es e ?caros, e sobre o estresse causado pelo ataque desses artr?podes. Com isso, esse trabalho teve por objetivo avaliar o desenvolvimento de organismos n?o alvos em algod?o geneticamente modificado. E avaliar o estresse fisiol?gico causado pelo ataque de ?caros e pulg?es em algod?o transg?nico e convencional. De acordo com os resultados obtidos ? poss?vel concluir que as toxinas Cry1F e Cry1Ac n?o exercem qualquer efeito no desenvolvimento do T. ludeni, e que o algod?o Bt foi menos infestado por A. gossypii. A severidade da infesta??o desses artr?podes causa altera??es nos par?metros da fluoresc?ncia da clorofila, promovendo estresse fisiol?gico nas plantas, tanto do algod?o Bt como da isolinha. Coletivamente, esses resultados fornecem fortes evid?ncias de que a tecnologia Bt pode complementar outras t?ticas integradas de controle de pragas, especialmente se em conjunto com o controle biol?gico. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Brazil is one of the world's largest cotton producers, not only in terms of volume but also in quality and innovation. However, insect pest attack is one of the main barriers to cotton productivity, which is accentuated by large areas of monoculture. One of the management tactics that is being used is the resistance of plants. The culture hosts several organisms, including a large number of arthropods such as the aphid Aphis gossypii Glover 1877 (Hemiptera: Aphididae) and the phytophagous spider mite Tetranychus ludeni zacher, 1913 (Acari: Tetranychidae), which feed on the aerial part of the plants. Cause economic losses. The transgenic varieties used in pest management are developed to control a particular group of insects, according to the toxin they express. However, when expressed continuously, these toxins are exposed to other plant-eating herbivores, raising concerns that large-scale use of this technology may have adverse effects on non-target arthropods. The impact of Bt proteins on non-target arthropods is less understood than its effects on target organisms where the mechanism of toxic action is known. There is little information on the effects of Bt transgenics on populations of aphids and mites, and on the stress caused by the attack of these arthropods. The objective of this work was to evaluate the development of non-target organisms in genetically modified cotton and to evaluate the physiological stress caused by the attack of spider mites and aphids in transgenic and conventional cotton. According to the results obtained it is possible to conclude that the toxins Cry1F and Cry1Ac have no effect on the development of T. ludeni, and that Bt cotton was less infested by A. gossypii. The severity of the infestation of these arthropods causes changes in chlorophyll fluorescence parameters, promoting plant Physiological stress in both Bt cotton and isoline. Collectively, these results provide strong evidence that Bt technology can complement other integrated pest control tactics, especially if coupled with biological control.
7

Avaliação dos efeitos do fipronil (ingrediente ativo do FRONTLINE®) nos ovários de carrapatos Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) e no sangue periférico de roedores /

Oliveira, Patrícia Rosa de. January 2010 (has links)
Resumo: O presente estudo avaliou os efeitos do fipronil em fêmeas semi-ingurgitadas de carrapatos Rhipicephalus sanguineus por meio do desenvolvimento de protocolo adequado de bioensaio in vitro (AIT), monitorado diariamente, com determinação da CL50 (concentração 50% letal) e intervalo de confiança a 95%, g (95): CL50 = 9.647 ppm (4.711 a 13.470), bem como analisou os efeitos histológicos e ultra estruturais deste produto nos ovários desses indivíduos, demonstrando quais são os mecanismos de defesa utilizados pelas células germinativas para eliminar o composto químico do sistema. Para o estudo morfológico, os carrapatos foram divididos em quatro grupos, onde o grupo I foi utilizado como controle e os grupos II, III e IV, foram submetidos às concentrações de 1, de 5 e de 10 ppm (CL50) de fipronil, respectivamente. As alterações variaram desde a presença de poucos e pequenos vacúolos até a interrupção da vitelogênese e morte celular. A concentração de 10 ppm de fipronil foi a que mais afetou o desenvolvimento dos ovócitos. Mecanismos de defesa celular como o aumento da quantidade e novo arranjo citoplasmático de elementos do citoesqueleto, bem como a grande quantidade de vacúolos digestivos e de figuras mielínicas foram observados. Simulando a ação do fipronil nos hospedeiros de carrapatos expostos aos acaricidas que tenham esse princípio ativo em sua composição, o presente estudo avaliou também o potencial citotóxico (danos causados nas células do fígado), genotóxico e mutagênico do fipronil utilizando camundongos submetidos a diferentes doses da droga. Os camundongos foram divididos em quatro grupos: grupo controle e grupos I, II e III, que foram expostos às doses de 15mg/Kg, 25 mg/Kg e 50 mg/Kg (DL50) de fipronil, respectivamente. Em seguida, o fígado dos indivíduos foi retirado, seccionado e analisado por meio de técnicas histológicas e histoquímicas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study evaluated the effects of fipronil on semi-engorged females of the tick Rhipicephalus sanguineus. A protocol for an in vitro bioassay (AIT) was developed, and the LC50 (lethal concentration 50%) and 95% confidence interval were determined: LC50 = 9.647 ppm (4.711 to 13.470). Histological and ultrastructural alterations in ovaries were also examined to describe the defense mechanisms of germ cells to eliminate the chemical compound from the system. For the morphological analysis, ticks were divided into four groups. Group I was used as the control group and groups II, III,and IV were exposed to concentrations of 1, 5, and 10 ppm (LC50) of fipronil, respectively. Alterations varied from the presence of few and small vacuoles to the interruption of vitellogenesis and cell death. The concentration of 10 ppm of fipronil had the strongest effect on oocyte development. Defense mechanisms of cells were observed such as increase in the amount and changes in the arrangement in the cytoskeleton elements in the cytoplasm, amount of digestive vacuoles and myelin figures. Simulating the action of fipronil in tick hosts exposed to fipronil, the present study also assessed the cytotoxic (damage caused in liver cells), genotoxic, and mutagenic potential of fipronil in mice treated with different doses. Mice were divided into four groups: control group and groups I, II, and III, which were exposed to doses of 15mg/Kg, 25 mg/Kg, and 50 mg/Kg (LD50) de fipronil, respectively. The liver of mice were dissected, sectioned, and analyzed with histological and histochemical techniques. Changes varied from proliferation of Kupffer cells, hypertrophy of hepatocytes, accumulation and distribution of proteins, polysaccharides, lipids, and presence of vacuoles in the cytoplasm of hepatocytes, as well as the obstruction of blood vessels, characterizing mainly a) autophagic processes, b) steatosis... (Complete abstract click electronic access below) / Orientador: Maria Izabel Camargo Mathias / Coorientador: Gervásio Henrique Bechara / Banca: Marcelo B. Labruna / Banca: Edson Luis Maistro / Banca: Odair Correa Bueno / Banca: Darci Moraes Barros-Battesti / Doutor
8

Efeito da soja geneticamente modificada DAS-81419-2, que expressa as proteínas Cry1Ac e Cry1F, sobre os organismos-alvo e na comunidade de artrópodes não-alvo / Effect of genetically modified soybean DAS-81419-2 expressing the proteins Cry1Ac and Cry1F on the target-organisms and non-target arthropod community

Marques, Luiz Henrique da Silva Fagundes 28 April 2017 (has links)
A soja (Glycine max (L.) Merrill) com o evento DAS-81419-2 (ConkestaTM technology) que expressa as proteínas de Bacillus thuringiensis (Bt) Cry1F e Cry1Ac protege a cultura de danos de alimentação de lepidópteros-praga primários e secundários. Experimentos de campo foram conduzidos de 2011 à 2016 na região sul e central do Brasil para caracterizar a eficácia da soja DAS-81419-2 infestada com Anticarsia gemmatalis (Lepidoptera: Erebidae), Chrysodeixis includens (Lepidoptera: Noctuidae), Chloridea virescens (Lepidoptera: Noctuidae), Spodoptera cosmioides (Lepidoptera: Noctuidae), Elasmopalpus lignosellus (Lepidoptera: Pyralidae), Agrotis ipsilon (Lepidoptera: Noctuidae) e Helicoverpa armigera (Lepidoptera: Noctuidae) durante os estágios vegetativo (V4) e reprodutivo (R2 e/ou R4) da cultura. A eficácia da soja DAS-81419-2 foi comparada com a variedade isogênica não-Bt manejada com ou sem inseticidas foliares comerciais para controle de lepidópteros. DAS-81419-2 reduziu significantemente o dano de alimentação causado por A. gemmatalis, C. includens, C. virescens, S. cosmioides e H. armigera durante os estágios vegetativo e reprodutivo, bem como, a mortalidade de plântulas causada por E. lignosellus. Entretanto, DAS-81419-2 apresentou moderada atividade em A. ipsilon. Além disto, um estudo de campo de três anos avaliou os potenciais efeitos adversos de DAS-81419-2 por meio da inspeção da diversidade e abundância de artrópodes não-alvos comparado com a isolinha não-Bt com ou sem aplicações convencionais de inseticidas. Estes estudos foram conduzidos em três regiões produtoras de soja onde os artrópodes não-alvos da parte aérea e da superfície do solo foram monitorados. Em geral, a abundância e diversidade total não foram afetadas signifativamente pela soja Bt. Desta maneira, DAS-81419-2 mostrou eficácia consistente ao longo dos anos, localidades e diferente estágios da cultura contra lepidópteros-pragas primários e secundários de importância econômica da cultura da soja e não afetou adversamente os artrópodes não-alvos que ocorrem nos campos de soja. / Soybean (Glycine max (L.) Merrill) event DAS-81419-2 (ConkestaTM technology) expresses Bacillus thuringiensis (Bt) Cry1F and Cry1Ac proteins to provide protection against primary and secondary lepidopteran pest feeding damage. Field experiments were conducted from 2011 to 2016 in southern and central Brazil to characterize the efficacy of DAS-81419-2 soybean infested with Anticarsia gemmatalis (Lepidoptera: Erebidae), Chrysodeixis includens (Lepidoptera: Noctuidae), Chloridea virescens (Lepidoptera: Noctuidae), Spodoptera cosmioides (Lepidoptera: Noctuidae), Elasmopalpus lignosellus (Lepidoptera: Pyralidae), Agrotis ipsilon (Lepidoptera: Noctuidae), and Helicoverpa armigera (Lepidoptera: Noctuidae) during vegetative (V4) and reproductive (R2 and/or R4) crop developmental stages. The efficacy of DAS-81419-2 was compared to a non-Bt isogenic variety managed with or without applications of commercial foliar insecticides for lepidopteran control. DAS-81419-2 significantly reduced the feeding damage caused by A. gemmatalis, C. includens, C. virescens, S. cosmioides, and H. armigera during both vegetative and reproductive crop growth stages as well as the seedling stage plant mortality caused by E. lignosellus. However, DAS-81419-2 showed moderate activity on A. ipsilon. In addition, a 3-yr in-field study evaluated the potential adverse effects of DAS-81419-2 by examining the diversity and abundance of non-target arthropods (NTAs) compared to the non-Bt near isoline with and without conventional insecticide applications. These studies were conducted in three Brazilian soybean producing regions where both soil surface and aerial NTA were monitored. Overall, the total abundance and diversity were not significantly affected by Bt soybean. Therefore, DAS-81419-2 showed consistent efficacy across years, locations, and crop stages against the most economically important primary and secondary lepidopteran pests of soybean and did not adversely affect non-target arthropods occurring in soybean field.
9

Efeitos de inibidores de proteinases de soja em organismos não-alvo associados à cultura da cana-de-açúcar / Effects of soybean proteases inhibitors on non-target organisms associated to sugarcane

Simões, Renata Araújo 17 January 2008 (has links)
Genes de plantas que codificam inibidores de enzimas digestivas de insetos têm sido introduzidos em plantas cultivadas visando o controle de pragas. Os inibidores de proteinases estão presentes nos tecidos vegetais, principalmente nas sementes, e atuam em resposta a ataques por herbívoros e patógenos. Inibidores de serino-proteinases (IPs) dos tipos Bowman-Birk e Kunitz isolados de sementes de soja foram inseridos em variedades de cana-de-açúcar para aumentar a resistência à broca Diatraea saccharalis (Fabr.), principal praga desta cultura. Para utilização de plantas geneticamente modificadas contendo inibidores de proteinases é necessário um conhecimento profundo de sua sustentabilidade e segurança ambiental, determinando a estabilidade da característica inserida e os seus efeitos nos organismos não-alvo. O objetivo desta pesquisa foi avaliar os efeitos diretos e indiretos de inibidores de proteinases de soja em organismos não-alvos: um parasitóide larval, Cotesia flavipes (Cam.) (Hymenoptera: Braconidae); um patógeno, Metarhizium anisopliae (Mestch.) Sorokin (Deuteromycotina: Hyphomycetes); um polinizador, Apis mellifera L. (Hymenoptera: Apidae) e um decompositor, Scheloribates praeincisus (Berlese) (Acari: Oribatida: Scheloribatidae); associados à cultura da cana-de-açúcar. O consumo de Kunitz e BBI não afetou a sobrevivência de S. praeincisus. Por outro lado, a ingestão dos inibidores semi-purificados e purificados do tipo Kunitz diminuiu a duração das fases imaturas de S. praeincisus. A ingestão de folhas de cana GM expressando inibidores de proteinases (Kunitz e BBI) não afetou o tempo de desenvolvimento e a sobrevivência dos imaturos deste oribatídeo quando comparada à ingestão de suas isolinhas. Os inibidores de proteinases semi-purificados e purificados não afetaram a duração dos períodos larval e pupal, o peso e número de pupas e percentual de emergência do parasitóide C. flavipes em D. saccharalis. Por outro lado, a proporção de fêmeas em relação a machos de C. flavipes foi maior no tratamento onde as lagartas foram alimentadas com dieta contendo 0,5% de inibidores semi-purificados comparado-se à testemunha. A proporção fêmea:macho foi significativamente maior também quando os parasitóides foram alimentados com o inibidor do tipo Kunitz em relação ao controle e aos parasitóides alimentados com BBI. A adição de 0,5% (p/v) de inibidores de proteinases semi-purificados e 0,05% (p/v) de inibidores purificados do tipo Kunitz nos meios de cultura MC e BDA resultaram em maiores crescimento vegetativo e produção de conídios de M. anisopliae. Os inibidores purificados do tipo BBI não alteraram a esporulação do fungo. Os resultados dos estudos com A. mellifera não foram conclusivos e novas investigações precisam ser conduzidas para esclarecer os potenciais efeitos de inibidores de proteinases em abelhas. De uma forma geral, observou-se que os inibidores de proteinases (Kunitz e BBI) não afetaram negativamente os organismos não-alvo testados. Por outro lado, a ingestão de inibidor do tipo Kunitz alterou positivamente alguns parâmetros biológicos de C. flavipes, M. anisopliae e S. praeincisus. / Genes of plants expressing insect proteinase inhibitors have been introduced into plants for pest control. Proteases inhibitors are present in plant tissues, mainly in seeds, and act in response to predators and pathogens. The Bowman-Birk type and Kunitz type of serine proteases inhibitors (PI) from soybean seeds are been used to increase resistance of sugarcane to Diatraea saccharalis (Fabr.), the most important pest of this crop. The sustainability and environmental safety of PI crops is still unknown. For these reasons, it is necessary to understand the stability and the non-target effects of this new trait. The objective of this study was to evaluate the direct and indirect effects of soybean PI on the following non-target organisms associated to sugarcane: the larval parasitoid, Cotesia flavipes (Cam.) (Hymenoptera: Braconidae); the entomopathogen, Metarhizium anisopliae (Mestch.) Sorokin (Deuteromycotina: Hyphomycetes); the pollinator Apis mellifera L. (Hymenoptera: Apidae) and the soil mite involved in the process of recycling organic matter, Scheloribates praeincisus (Berlese) (Acari: Oribatida: Scheloribatidae). Kunitz and BBI did not affect S. praeincisus survival. On the other hand, Kunitz semi-purified and purified inhibitor ingestion reduced duration of the immature stages of S. praeincisus. Ingestion of GM senescent leaves did not have an effect on mite immatures development time and survival compared to ingestion of its isolines leaves. The semi-purified and purified proteinases inhibitors did not alter either the duration of larval and pupal stages of C. flavipes on D. saccharalis, or weight and number of pupae and parasitoid emergence. In other hand, the parasitism and proportion of female was higher on the treatment where caterpillars were fed with diet containing 0.5% of semi-purified inhibitors, comparing to control. The ratio female:male was significantly higher also when parasitoids were fed to the Kunitz type inhibitor compared to the control and BBI. The addition of 0.5 % (w/v) of semi- purified proteinase inhibitors and 0.05% (w/v) of Kunitz type purified inhibitors on two culture media (CM and PDA), resulted in increase of vegetative growth and production of conidia. BBI type purified inhibitors did not change the fungus sporulation. The results from the studies with A. mellifera were not conclusive and investigations are needed to clarify the potential impact of proteinase inhibitors on A. mellifera. Overall, proteinase inhibitors (Kunitz and BBI) did not negatively affect the non-target organisms tested. Conversely, ingestion of the Kunitz type of proteinase inhibitors altered positively some biological parameters of C. flavipes, M. anisopliae and S. praeincisus.
10

Subletální vliv agrochemikálií na pavouky rodu Pardosa / Sublethal effect of agrochemicals on \kur{Pardosa} sp.

KRIŠTOFOVÁ, Lucie January 2017 (has links)
In the last decades, there has been a growing interest in studying particular those arthropods who have an important role in agroecosystems. For example, they are natural enemies of pests and therefore they are considered to be beneficial organisms. However, these beneficial arthropods may be negatively affected by the application of chemicals under the management of agroecosystems and their potential to inhibit pests can be significantly reduced. Such organisms certainly include spiders which occure in abundant numbers practically in all types of terrestrial habitats including agricultural ecosystems where they have a role of very important predators. Therefore, the thesis focused on current issues of pesticides, especially from the view of their negative effects on behavioral modification of beneficial invertebrate organisms in agricultural crops. The theoretical part is devoted to a brief characteristics of pesticides, their sublethal effects on non-target organisms and the importance of spiders as natural regulators of pests in agroecosystems. The practical part describes the experiment whereconventionally used agrochemicals were tested the influence of the herbicide and desiccant Basta 15, the Arrest preparation and their combination (mixture Basta 15 + Arrest) on spiders genus Pardosa. I focused on the side effects of these solutions, specifically on the modification of predatory behavior and on the mortality of spiders. It has been shown that agrochemicals affect the predation successfulness of spiders. From the short term and the long term point of view, it has been shown that spiders treated with the tested preparations killed less prey than the individuals in the control group which were treated only with distilled water. The dependence of mortality and the number of killed prey on the size and sex has not been proved. Preparations Basta 15 and the mixture caused significantly higher mortality of spiders. The Arrest preparation did not increase the mortality.

Page generated in 0.0828 seconds