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  • 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

Biochemische und röntgenkristallographische Untersuchungen an pflanzlichen 4-Hydroxyphenylpyruvat-Dioxygenasen Röntgenstrukturanalyse der löslichen anorganischen Pyrophosphatase aus Heliothis virescens /

Fritze, Iris Maria. January 2003 (has links) (PDF)
München, Techn. Universiẗat, Diss., 2003.
2

Perspectiva de utilização da técnica do inseto estéril para lagarta da maçã Heliothis virescens (Lepidoptera: Noctuidae) e lagarta do velho mundo Helicoverpa armigera (Lepidoptera: Noctuidae) na cultura do algodoeiro como um método alternativo de controle / Perspective of using the sterile insect technique for Tobacco Budworms Heliothis virescens (Lepidoptera: Noctuidae) and Cotton Bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) in cotton crop as an alternative method of control

Haddad, Gianni Queiroz 16 March 2017 (has links)
Desde a década de 50, os cientistas tem utilizado radiação ionizante para esterilizar insetos, que são liberados na natureza para acasalar, mas sem nenhuma descendência. Conhecida como a técnica do inseto estéril (TIE), este método de controle de inseto vem tradicionalmente utilizando radiações ionizantes para esterilizar os insetos, sendo uma técnica que não gera resíduo, e pode agir em sinergia com as demais técnicas dentro do manejo integrado de pragas. O Brasil por vários anos vem lutando contra o aumento de pragas, introduzindo novas táticas e técnicas dentro dos programas de MIP, para driblar a resistência dos produtos químicos, como: diminuir os resíduos dos agrotóxicos; para algumas culturas importantes do o nosso país, temos um largo espectro de pragas ocorrendo do inicio ao fim da colheita, uma delas é a cultura do algodoeiro e dentre as pragas chave dessa cultura, temos algumas lagartas extremamente importantes, entre elas Heliothis virescens e Helicoverpa armigera. Essas espécies são parecidas morfologicamente, sendo a segunda identificada a poucos anos aqui no Brasil. Ainda não há trabalhos no Brasil utilizando TIE como ferramenta adicional para lepidópteros, portanto objetivou-se com esse estudo avaliar o efeito de doses de radiação gama nas diferentes fases do ciclo evolutivo de Heliothis virescens e Helicoverpa armigera, bem como avaliar a esterilidade na geração P e a capacidade de competição dos insetos irradiados com os não irradiados. A fase pupa foi a que apresentou um melhor resultado, pois com 75 Gy atingiu a esterilidade em Heliothis virecens e 100 Gy esterilizou Helicoverpa armigera, portanto contemplou a fase e a dose escolhida para avaliar a competição entre os insetos irradiados e os insetos normais de ambas as espécies. E tanto Heliothis virecens como Helicoverpa armigera apresentaram um resultado satisfatório, pois os insetos irradiados conseguiram reduzir significativamente a viabilidade dos ovos na proporção de 9: 1: 1 / Since the 1950s, scientists have used ionizing radiation to sterilize insects, which are released in nature to mate, but without any progeny. Known as the sterile insect technique (TIE), this method of insect control has traditionally used ionizing radiation to sterilize insects, a technique that does not generate residues, and can act in synergy with the other techniques within integrated pest management. For several years, Brazil has been fighting against the increase of pests, introducing new tactics and techniques within the IPM programs, to overcome the resistance of chemical products, such as: reducing the residues of agrochemicals; For some important crops of our country, we have a wide spectrum of pests occurring from the beginning to the end of the harvest, one of them is the cotton crop and among the key pests of this crop, we have some extremely important caterpillars, among them Heliothis virescens and Helicoverpa armigera These species are morphologically similar, the second being identified a few years ago in Brazil. There are still no studies in Brazil using TIE as an additional tool for Lepidoptera, therefore the purpose of this study was to evaluate the effect of doses of gamma radiation in the different phases of the evolutionary cycle of Heliothis virescens and Helicoverpa armigera, as well as to evaluate the sterility in generation P And the ability of insects to irradiate with non-irradiated insects. The pupal phase presented the best result because 75 Gy achieved sterility in Heliothis virecens and 100 Gy sterilized Helicoverpa armigera, therefore it contemplated the phase and dose chosen to evaluate the competition between the irradiated insects and the normal insects of both species. Both Heliothis virecens and Helicoverpa armigera presented a satisfactory result, as the irradiated insects managed to significantly reduce the viability of the eggs in a ratio of 9: 1: 1
3

Efeito de um inibidor de proteinase serinica sobre o desenvolvimento e atividade enzimatica de Heliothis virescens (Lepidopter: Noctuidae) / Effect of a trypsin inhibitor on the development and enzymatic activity of Heliothis virescens (Lepidoptera: Noctuidae)

Kubo, Carlos Eduardo Gavira 27 February 2007 (has links)
Orientador: Maria Ligia Rodrigues Macedo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T03:11:15Z (GMT). No. of bitstreams: 1 Kubo_CarlosEduardoGavira_M.pdf: 1973367 bytes, checksum: afd46afbc30805315577f477defd25c7 (MD5) Previous issue date: 2007 / Resumo: As plantas sintetizam inibidores de proteinases (IPs) como um dos mecanismos de defesa contra o ataque de insetos-praga e patógenos. Os IPs são polipeptídios hábeis em se ligar às enzimas proteolíticas localizadas no intestino médio dos insetos, impedindo sua atividade proteolítica por inibição competitiva. Esse processo leva a uma redução da disponibilidade de aminoácidos para a síntese protéica, e desta maneira, a uma redução no crescimento e desenvolvimento por parte do inseto. Portanto, os IPs são considerados fatores anti-metabólicos. Heliothis virescens (Fabr., 1781) (Lepidoptera: Noctuidae) é uma mariposa, cujas larvas atacam principalmente culturas em campo como: alfafa, algodão, soja e fumo. Entretanto, ocasionalmente podem atacar também culturas como couve, alface, ervilha, pimentão, guandu, abóbora e tomate. Neste trabalho, um inibidor purificado das sementes de Adenanthera pavonina L. (Mimosaceae) ¿ ApTI foi utilizado em dietas artificiais, e através de bioensaios seu potencial inseticida contra H. virescens foi determinado. A inibição in vitro de proteinases do inseto por ApTI sugerem que o inibidor possua efeitos anti-metabólicos quando ingeridos pelas larvas . Entretanto, a ingestão de ApTI não resultou em uma redução significativa no crescimento e desenvolvimento do inseto. Não sendo observadas diferenças na mortalidade larval, no ganho de peso e no tempo de desenvolvimento larval e pupal. A fim de estudar a adaptação das lagartas à presença do inibidor, a atividade das proteinases intestinais das larvas que se alimentaram em dietas livres do inibidor e alimentadas em dieta contendo o inibidor a 0,4% foi comparada através de ensaios enzimáticos e eletroforese em géis de atividade enzimática. As larvas de quarto instar alimentadas em dieta contendo ApTI apresentaram um aumento de cerca de duas vezes na atividade tríptica, confirmado por ensaios enzimáticos e na eletroforese de atividade. Além disso, a atividade tríptica das larvas que se alimentaram em dieta com ApTI é menos sensível a inibição por ApTI, indicando que novas enzimas mais resistentes ao inibidor foram produzidas. Estes resultados sugerem que as larvas de H. virescens foram capazes de se adaptarem fisiologicamente ao inibidor pela superprodução de enzimas do tipo tripsina existente e pela produção de um novo tipo de enzima do tipo tripsina que é menos susceptível a ação inibitória de ApTI / Abstract: Proteinase inhibitor proteins (PIs) are one of the defensive chemicals produced by plants against pests and pathogens. PIs are polypeptides that are able to bind to insect midgut proteolytic enzymes, rendering them inactive by competitive inhibition. This process leads to a limitation of essential amino acids in protein synthesis, and thus, to reduction in growth and development. Therefore, PIs are known as antinutritional factors. The tobacco budworm, Heliothis virescens (Fabr., 1781) (Lepidoptera: Noctuidae) is a polyphagous insect larvae that is principally a field crop pest, attacking such crops as alfalfa, cotton, soybean and tobacco. However, it sometimes attacks such vegetables as cabbage, lettuce, pea, pepper, pigeon pea, squash, and tomato, especially when cotton or other favored crops are abundant. In this report, the pure inhibitor from seeds of Adenanthera pavonina L. (Mimosaceae) ¿ ApTI was monitoring by an insect bioassay its insecticidal activity toward H. virescens. The in vitro inhibitions of proteinases activities by ApTI suggest that ApTI would have a potential antimetabolic effect when ingested by insect larvae. However, chronic ingestion of ApTI did not result in a significant reduction of growth and development of tobacco budworm. No differences in larval mortality, weight gain, larval and pupal developmental time were observed. To study this adaptation, the midgut proteinases of H. virescens larvae reared on artificial PI-free diet and on a diet containing ApTI at 0.4% were compared by using enzymatic assays and polyacrilamide gel electrophoresis. The fourth instar larvae reared on a diet containing ApTI showed a 2-fold increase in tryptic activity, as confirmed by BApNA as substrate and by activity in gels. In addition, the tryptic activity in ApTI-fed larvae was less sensitive to ApTI, indicating that novel proteolytic form resistant to ApTI was induced in larvae reared on a diet containing this inhibitor. These results suggest that H. virescens larvae were able to physiologically adapt to inhibitor by overproduction of an existing trypsin-like enzyme and production of a new type of trypsin-like enzyme that is less susceptible to inhibitory action of ApTI / Mestrado / Bioquimica / Mestre em Biologia Funcional e Molecular
4

Perspectiva de utilização da técnica do inseto estéril para lagarta da maçã Heliothis virescens (Lepidoptera: Noctuidae) e lagarta do velho mundo Helicoverpa armigera (Lepidoptera: Noctuidae) na cultura do algodoeiro como um método alternativo de controle / Perspective of using the sterile insect technique for Tobacco Budworms Heliothis virescens (Lepidoptera: Noctuidae) and Cotton Bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) in cotton crop as an alternative method of control

Gianni Queiroz Haddad 16 March 2017 (has links)
Desde a década de 50, os cientistas tem utilizado radiação ionizante para esterilizar insetos, que são liberados na natureza para acasalar, mas sem nenhuma descendência. Conhecida como a técnica do inseto estéril (TIE), este método de controle de inseto vem tradicionalmente utilizando radiações ionizantes para esterilizar os insetos, sendo uma técnica que não gera resíduo, e pode agir em sinergia com as demais técnicas dentro do manejo integrado de pragas. O Brasil por vários anos vem lutando contra o aumento de pragas, introduzindo novas táticas e técnicas dentro dos programas de MIP, para driblar a resistência dos produtos químicos, como: diminuir os resíduos dos agrotóxicos; para algumas culturas importantes do o nosso país, temos um largo espectro de pragas ocorrendo do inicio ao fim da colheita, uma delas é a cultura do algodoeiro e dentre as pragas chave dessa cultura, temos algumas lagartas extremamente importantes, entre elas Heliothis virescens e Helicoverpa armigera. Essas espécies são parecidas morfologicamente, sendo a segunda identificada a poucos anos aqui no Brasil. Ainda não há trabalhos no Brasil utilizando TIE como ferramenta adicional para lepidópteros, portanto objetivou-se com esse estudo avaliar o efeito de doses de radiação gama nas diferentes fases do ciclo evolutivo de Heliothis virescens e Helicoverpa armigera, bem como avaliar a esterilidade na geração P e a capacidade de competição dos insetos irradiados com os não irradiados. A fase pupa foi a que apresentou um melhor resultado, pois com 75 Gy atingiu a esterilidade em Heliothis virecens e 100 Gy esterilizou Helicoverpa armigera, portanto contemplou a fase e a dose escolhida para avaliar a competição entre os insetos irradiados e os insetos normais de ambas as espécies. E tanto Heliothis virecens como Helicoverpa armigera apresentaram um resultado satisfatório, pois os insetos irradiados conseguiram reduzir significativamente a viabilidade dos ovos na proporção de 9: 1: 1 / Since the 1950s, scientists have used ionizing radiation to sterilize insects, which are released in nature to mate, but without any progeny. Known as the sterile insect technique (TIE), this method of insect control has traditionally used ionizing radiation to sterilize insects, a technique that does not generate residues, and can act in synergy with the other techniques within integrated pest management. For several years, Brazil has been fighting against the increase of pests, introducing new tactics and techniques within the IPM programs, to overcome the resistance of chemical products, such as: reducing the residues of agrochemicals; For some important crops of our country, we have a wide spectrum of pests occurring from the beginning to the end of the harvest, one of them is the cotton crop and among the key pests of this crop, we have some extremely important caterpillars, among them Heliothis virescens and Helicoverpa armigera These species are morphologically similar, the second being identified a few years ago in Brazil. There are still no studies in Brazil using TIE as an additional tool for Lepidoptera, therefore the purpose of this study was to evaluate the effect of doses of gamma radiation in the different phases of the evolutionary cycle of Heliothis virescens and Helicoverpa armigera, as well as to evaluate the sterility in generation P And the ability of insects to irradiate with non-irradiated insects. The pupal phase presented the best result because 75 Gy achieved sterility in Heliothis virecens and 100 Gy sterilized Helicoverpa armigera, therefore it contemplated the phase and dose chosen to evaluate the competition between the irradiated insects and the normal insects of both species. Both Heliothis virecens and Helicoverpa armigera presented a satisfactory result, as the irradiated insects managed to significantly reduce the viability of the eggs in a ratio of 9: 1: 1
5

Desempenho de espécies de Trichogramma West. (Hym:Trichogrammatidae) para o controle de Heliothis virescens (Fabr.) (Lep.: Noctuidae) / Potential of Trichogramma West. (Hym:Trichogrammatidae) species to control Heliothis virescens (Fabr.) (Lep.: Noctuidae)

ANDRADE, Gilberto Santos 01 February 2007 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-11-24T15:08:38Z No. of bitstreams: 1 Gilberto Santos Andrade.pdf: 539005 bytes, checksum: 575c35c9686dfc82cb2bf5b3882e07f1 (MD5) / Made available in DSpace on 2016-11-24T15:08:38Z (GMT). No. of bitstreams: 1 Gilberto Santos Andrade.pdf: 539005 bytes, checksum: 575c35c9686dfc82cb2bf5b3882e07f1 (MD5) Previous issue date: 2007-02-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / One important aspect of maximizing pest natural mortality factors is to enhance the action of natural enemies into integrated pest management programs. Species of the egg parasitoid Trichogramma have been investigated and used successfully around the world. To boost the utilization of these parasitoids as biological control agent, basic studies on species selection regarding the interactions with environmental conditions and host plants is needed. In Brazil, Trichogramma pretiosum Riley is recommended to control lepidopteran pests of cotton. Thus, this research evaluated the potential of other three Trichogramma species in comparison to T. pretiosum parasitizing eggs of tobacco budworm Heliothis virescens (Fabr.) under constant (20, 25 and 30oC) and alternated (immature development at 25oC and adult submitted to 20 and 30oC) temperatures. Additionally, the best performing species at these temperature regimes were tested when offering egg of the host tobacco budworm on cotton leaves of two varieties (ca. colored BRS Safira and white fibers BRS 8H). The species studied were: Trichogramma exiguum Pinto & Platner, Trichogramma atopovirilia Oatman & Platner, Trichogramma acacioi Brun, Moraes & Soares and T. pretiosum. The evaluated parameters were: parasitism rate and its viability, sex ratio of the progeny and number of descendents emerged per egg parasitized. Overall, T. atopoviriliaexhibited the best performance through all temperature regimes studied. T. pretiosum and T.exiguum achieved similar parasitism rate of H. virescens eggs, while T. acacioi showed the lower performance. Based on the results above, parasitism of eggs offered on cotton leaves was conducted with the species T. exiguum, T. pretiosum and T. atopovirilia. The cotton variety affected the parasitism rate of T. exiguum and T. atopovirilia resulting in lower parasitism when eggs were offered on BRS Safira cotton leaves, but it was similar for T. pretiosum. Therefore, under constant and alternating temperatures and host exposure on cotton leaves all species parasitized eggs of H. virescens, but T. atopovirilia exhibited better performance in comparison to the others. Therefore, further studies should be conducted looking for other field aspects related with the use of this parasitoid such as dispersion and field parasitism. / Espécies do gênero Trichogramma têm sido pesquisadas em todo o mundo para o controle biológico de lepidópteros-praga. Para que a eficiência desses parasitóides seja aumentada faz-se necessário a realização de estudos básicos visando à seleção de espécies em relação ao ambiente e seus hospedeiros. No Brasil, a espécie Trichogramma pretiosum Riley é a mais utilizada para o controle de lepidópteros-praga do algodoeiro. Assim, comparou-se o desempenho de outras espécies tais como: Trichogramma exiguum Pinto & Platner, Trichogramma atopovirilia Oatman & Platner e Trichogramma acacioi Brun, Moraes & Soares (Hym.: Trichogrammatidae) parasitando ovos de Heliothis virencens (Fabr.) (Lep.: Noctuidae) sob temperaturas constantes (20, 25 e 30oC) e alternadas (fase imatura a 25oC e adultos submetidos a 20 e 30oC para parasitismo). Adicionalmente, as espécies com melhor desempenho nas temperaturas estudadas foram testadas oferecendo ovos de H. virescens em folhas de algodoeiro das cultivares BRS 8H e BRS Safira. As variáveis avaliadas foram: porcentagem de parasitismo e viabilidade; razão sexual e número de indivíduos por ovo. T. atopovirilia foi a espécie com melhor desempenho em todas as condições térmicas estudadas constatado através da maior porcentagem de parasitismo. T. pretiosum e T. exiguum apresentaram a mesma taxa de parasitismo em ovos de H. virescens e T. acacioi obteve a menor taxa de parasitismo. Com base nesses resultados, o estudo oferecendoovos em folhas das duas cultivares de algodoeiro foi conduzido com T. exiguum, T. pretiosum e T. atopovirilia. As cultivares de algodoeiro afetaram o parasitismo de ovos de H. virescens de T. atopovirilia e T. exiguum, sendo inferior quando os ovos foram oferecidos em folhas de BRS Safira. Não houve efeito das cultivares no parasitismo de H. virescens por T. pretiosum. Os resultados evidenciam que T. atopovirilia e T. exiguum apresentaram melhor parasitismo de ovos depositados em BRS 8H e o parasitismo de T. atopovirilia foi superior aquele de T. pretiosum quando ovos encontravam-se sobre a cultivar BRS Safira. Assim, futuros estudos devem ser conduzidos com T. atopovirilia parasitando ovos de H. virescens em condição de campo e onde sejam analisadas variáveis como quantidade de parasitóides a serem liberados para a obtenção de taxas de parasitismo satisfatórias.
6

INHIBITORY PROPERTIES OF <i>MICROPLITIS CROCEIPES</i> TERATOCYTE SECRETORY PRODUCTS AND THE RECOMBINANT PROTEIN TSP14 ON PROTEIN SYNTHESIS

DiLuna, Francis Anthony 01 January 2003 (has links)
Microplitis croceipes is a solitary endoparasitic wasp that oviposits in the hemocoel of Heleothis virescens larvae. Upon parasitization, the host larvaes physiology is altered; resulting in a compromised immune system and a decrease in the production of some vital proteins resulting in a terminal post-wandering prepupal state. Teratocytes, cells derived from the extraembryonic serosa of the parasitic wasp, mimic symptoms of parasitization when injected into host larvae, independent of other factors like polydnavirus and venom. Some of the inhibition of protein synthesis can be attributed to proteins secreted by the teratocytes (teratocyte secretory proteins or TSP). A fraction of TSP between 330 kDa inhibits protein synthesis in vivo, in the in vitro fat body and testes assays, and in the rabbit reticulocyte lysate and wheat germ extract assays. This fraction, however, has no effect on nucleic acid synthesis. Its effect on protein synthesis is dose dependent and exposure time sensitive. A 13.9 kDa protein isolated from TSP and expressed in a baculovirus system seems primarily responsible for the inhibition. Although TSP14 production was low, it did bind to the cell surface, enter the cell, and inhibit protein synthesis as the 330 kDa factor did.
7

Comparing the midgut regenerative responses in <i>Bacillus thuringiensis</i>-susceptible and resistant <i>Heliothis virescens</i> larvae

Castagnola, Anais Severiana 01 December 2011 (has links)
The crystal (Cry) toxins from Bacillus thuringiensis (Bt) display high specificity and toxicity against relevant insect pests and the use of Bt-based products continues to contribute to insect pest management. To protect this investment, further its potential, and investigate possible unintended effects, various research questions have been proposed. One issue related to Bt usage is the evolution of pest resistance to Bt toxins. The midgut epithelium is targeted by Cry toxins killing enterocytes, facilitating invasion of the hemocoel, leading to septicemia and mortality. While resistance may emerge from alterations to these steps, most research efforts have been focused on reduced toxin binding to midgut receptors as resistance mechanism. Lepidopteran crop pest Heliothis virescens strains have been hypothesized to have enhanced midgut proliferation and differentiation of stem cell populations allowing for regeneration and resistance to diverse Cry toxins. However, the molecular mechanisms involved are not known. We developed a flow cytometry method to monitor stem cell proliferation and differentiation to compare midgut regenerative responses to Cry intoxication in larvae from susceptible and Bt-resistant strains of H. virescens. The structure of the epithelial healing response was studied in vivo using hematoxylin-eosin stained midguts derived from larvae fed Cry1Ac toxin. We detected less regenerative cells in midguts from a Bt-susceptible strain (YDK) compared to midguts from resistant (KCB and CXC) strains, and an overall increase in the total number of cells per unit surface area in KCB midguts. Using primary midgut cell cultures, the midgut regeneration response to Cry1Ac in CXC was an increase in available differentiated cells compared to YDK. In contrast, KCB exhibited an increased abundance of stem cells compared to both YDK and CXC. Using a differential proteomics approach we characterized the proteins secreted by H. virescens midgut cells in response to Cry1Ac and identified a relevant role for arylphorin in promoting midgut regeneration in response to Cry1Ac and DiPel intoxication in both susceptible and resistant H. virescens larvae. The potential fitness costs associated with altered hexamerin transcript expression were monitored using larval bioassays.

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