• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 40
  • 15
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 69
  • 39
  • 34
  • 32
  • 25
  • 18
  • 18
  • 15
  • 15
  • 14
  • 12
  • 10
  • 10
  • 9
  • 8
  • 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.
31

ALTERNATIVE METHODOLOGIES FOR BORESIGHT CALIBRATION OF GNSS/INS-ASSISTED PUSH-BROOM HYPERSPECTRAL SCANNERS ON UAV PLATFORMS

Tian Zhou (6114419) 10 June 2019 (has links)
<p>Low-cost unmanned aerial vehicles (UAVs) utilizing push-broom hyperspectral scanners are poised to become a popular alternative to conventional remote sensing platforms such as manned aircraft and satellites. In order to employ this emerging technology in fields such as high-throughput phenotyping and precision agriculture, direct georeferencing of hyperspectral data using onboard integrated global navigation satellite systems (GNSS) and inertial navigation systems (INS) is required. Directly deriving the scanner position and orientation requires the spatial and rotational relationship between the coordinate systems of the GNSS/INS unit and hyperspectral scanner to be evaluated. The spatial offset (lever arm) between the scanner and GNSS/INS unit can be measured manually. However, the angular relationship (boresight angles) between the scanner and GNSS/INS coordinate systems, which is more critical for accurate generation of georeferenced products, is difficult to establish. This research presents three alternative calibration approaches to estimate the boresight angles relating hyperspectral push-broom scanner and GNSS/INS coordinate systems. For reliable/practical estimation of the boresight angles, the thesis starts with establishing the optimal/minimal flight and control/tie point configuration through a bias impact analysis starting from the point positioning equation. Then, an approximate calibration procedure utilizing tie points in overlapping scenes is presented after making some assumptions about the flight trajectory and topography of covered terrain. Next, two rigorous approaches are introduced – one using Ground Control Points (GCPs) and one using tie points. The approximate/rigorous approaches are based on enforcing the collinearity and coplanarity of the light rays connecting the perspective centers of the imaging scanner, object point, and the respective image points. To evaluate the accuracy of the proposed approaches, estimated boresight angles are used for ortho-rectification of six hyperspectral UAV datasets acquired over an agricultural field. Qualitative and quantitative evaluations of the results have shown significant improvement in the derived orthophotos to a level equivalent to the Ground Sampling Distance (GSD) of the used scanner (namely, 3-5 cm when flying at 60 m).</p>
32

Avaliação da variabilidade de biotipos de Moniliophthora perniciosa / Evaluation of Moniliophthora perniciosa biotypes variability

Lia Matelli Garcia 04 February 2010 (has links)
O basidiomiceto Moniliophthora perniciosa é conhecido por causar a doença vassoura-debruxa no cacau (Theobroma cacao), responsável por grandes perdas de produção nessa cultura. A população de M. perniciosa apresenta variabilidade devido à sua capacidade de colonização de outras espécies de plantas, o que permite a identificação de biótipos e conseqüente agrupamento de isolados com base no hospedeiro. A caracterização de biotipos do fungo contribui para melhor conhecimento da estrutura populacional e sua dispersão, o que é importante para utilização em programas de melhoramento. Com esse objetivo foi avaliada a variabilidade genética e fisiológica de isolados do fungo correspondentes a três biotipos considerando a análise de taxas de crescimento pelo desenvolvimento micelial em diferentes meios e ambientes de cultivo in vitro, como a incorporação de cisteína, metionina e lisina e das fontes de nitrogênio tartarato de amônio e nitrato de potássio, iluminação, suscetibilidade a fungicidas, compatibilidade somática (SCG Grupo de Compatibilidade Somática), análise de perfis protéicos por SDS-PAGE e seqüenciamento parcial do 28S rDNA. A história evolutiva do patógeno não está registrada em seqüências de genes ribossomais e proteínas totais. Além disso, crescimento e produção de pigmentos são características compartilhadas pelos biótipos, não sendo fatores primários para adaptação do patógeno, porém com provável papel na colonização do hospedeiro. / The Basidiomycete Moniliophthora perniciosa is known as the pathogen for witches\' broom disease in cocoa (Theobroma cacao), responsible for large yield losts. Population of M. perniciosa presents variability due to its ability to colonize other plant species, which allows biotype identification and strains grouping, based upon the host specie. Fungi biotype characterization contributes to the knowledge of population and its dispersion and epidemiological methods, important for breeding programs. To aim the genetic and physiological variability of three strains, characteristics as growing rates, measured by the mycelia spreading at different culture media and different culture conditions in vitro, cysteine, methionine, lysine, nitrogen sources ammonium tartrate and potassium nitrate incorporation, light, fungicide susceptibility, somatic compatibility (SCG), protein patterns by SDS-PAGE and partial sequencing of rRNA 28S region were done. The evolutional history of it is pathogen is not printed into ribosomal genes sequences and total proteins. Besides that, growing and dye production are characteristics shared by the biotypes and can not be a primary adaptation factor but it can play a role in the host colonization process.
33

Estudo da função biológica da oxidase alternativa (AOX) de Moniliophthora perniciosa (fungo da vassoura de bruxa) em Saccharomyces cerevisiae / Study of the biological function of the alternative oxidase (AOX) from Moniliophthora pernicious (witches\' broom fungus) in Saccharomyces cerevisiae

Gabriel Moretti de Almeida 28 July 2014 (has links)
Moniliophthora perniciosa é um fungo basidiomiceto causador da doença vassoura de bruxa do cacaueiro. Um conjunto de técnicas para controle da doença vem sendo testado e aplicado, incluindo o uso de fungicidas a base de inibidores da cadeia respiratória principal, específicos para fungos. No entanto, M. perniciosa tem se mostrado resistente a estas drogas e uma possível explicação para tal resistência é a atividade de uma oxidase alternativa (AOXp), cuja expressão e atividade já vêm sendo caracterizadas. A análise funcional deste gene de M. perniciosa não foi realizada, pois uma técnica efetiva para produção de mutantes do fungo ainda não foi estabelecida. Assim, este projeto visou testar a hipótese de que a expressão do gene AOX de M. perniciosa (Mp-AOX) previne o estresse oxidativo devido à diminuição na produção de espécies reativas de oxigênio (ROS) pela cadeia respiratória. Para isso realizamos a caracterização do gene Mp-AOX por clonagem e expressão heteróloga em Saccharomyces cerevisiae. O vetor de expressão em levedura pYES2/CT com o gene Mp-AOX foi montado e a linhagem de levedura W303-1b transformada. Foram realizadas análises de medição de formação de massa celular, geração de espécies reativas de oxigênio (ROS) mitocondrial, testes de viabilidade na presença de inibidores da cadeia respiratória principal Antimicina A e azoxistrobina e do inibidor específico de AOXp - ácido salicil hidroxâmico (SHAM). Nossos resultados indicam que quando o gene Mp-AOX é expresso em S. cerevisiae há diminuição da geração de biomassa celular, menor proliferação celular e decaimento na produção de ROS, sugerindo que nossa hipótese inicial de que Mp-AOXp causa alívio no estresse oxidativo estar correta. A levedura recombinante expressando o gene Mp-AOX mostrou-se viável para utilização como modelo para estudos de novos análogos químicos para o combate da vassoura de bruxa, auxiliando a agricultura e promovendo novos entendimentos para o combate desse fungo. / Moniliophthora pernicious is a basidiomycete fungus that causes witches\' broom of cacao disease. A number of techniques for disease control has been applied and tested, including the use of the fungicides that inhibits the main respiratory chain, specific to fungi. However, M. pernicious has proven to be resistant to these drugs and one possible explanation to this resistance would be the activity of an alternative oxidase activity (AOXp), whose expression and activity have already been characterized. Functional analysis of this gene in M. pernicious was not performed because an effective technique for producing mutants of the fungus has not yet been established. This project aimed to test the hypothesis that the expression of Mp-AOX gene prevents oxidative stress due to decreased production of reactive oxygen species (ROS) by the respiratory chain. To perform this characterization, Mp- AOX gene was cloned and heterologous expressed in Saccharomyces cerevisiae. The yeast expression vector pYES2/CT with Mp-AOX gene was constructed and the yeast strain W303 - 1b transformed. Analyses measuring cell mass formation, generation of mitochondrial reactive oxygen species (ROS), viability tests challenging the cells against inhibitors of the main respiratory chain, Antimycin A and azoxystrobin, and against the specific inhibitor of the AOXp - salicylaldehyde hydroxamic acid (SHAM) were performed. Our results indicate that the Mp-AOX gene expression in S. cerevisiae causes decreased generation of cellular biomass, less cell proliferation and the decay in the production of ROS, suggesting that our initial hypothesis that Mp-AOXp reliefs the oxidative stress is correct. The recombinant yeast expressing Mp- AOX gene was feasible for use as a model for studies of new chemical to fight witches\' broom, helping with agriculture and promoting new understandings to combat this fungus.
34

Epidemiologia da vassoura-de-bruxa (Crinipellis perniciosa (STAHEL) Singer) em cacaueiros enxertados em Uruçuca, BA. / Epidemiology of witches' broom (Crinipellis perniciosa (STAHEL) Singer) on grafted cocoa in Uruçuca, BA.

Alves, Silvio André Meirelles 22 January 2003 (has links)
A vassoura-de-bruxa é a doença mais importante da cultura do cacaueiro, nos países onde ela ocorre. Em 1989 foi constatada pela primeira vez a presença do patógeno causador dessa doença na principal região produtora do Brasil. A falta de medidas de controle eficientes resultou, nos últimos anos, em menor produção, mudanças no uso da terra, venda de propriedades, diminuição do nível de emprego e danos ao meio ambiente. Em vista do pouco conhecimento sobre aspectos epidemiológicos da doença nas condições do sudeste da Bahia, elaborou-se o presente trabalho com os seguintes objetivos: estudar o gradiente de infecção da vassoura-de-bruxa em ramos e frutos em cacaueiros enxertados; comparar o efeito de genótipos e três tratamentos (poda fitossanitária semestral, poda fitossanitária mensal e poda fitossanitária aliada a aplicação de fungicida mensais) no controle da doença; estudar o progresso da vassoura-de-bruxa no tempo, quantificado em ramos e frutos doentes. O experimento foi conduzido em Uruçuca, BA, em área contendo 16 genótipos diferentes, adjacente a uma área com cacaueiros abandonados com alta incidência da doença. A área experimental foi dividida em três partes, as quais receberam os seguintes tratamentos: poda fitossanitária semestral, poda fitossanitária mensal e poda fitossanitária aliada a aplicação de fungicida mensal. Pelo menos uma vez por mês foram contados os ramos e frutos com vassoura. Os resultados mostraram a ausência de evidência clara da existência de gradiente de doença. Os níveis de resistência genética à vassoura-de-bruxa de ramos e frutos não foram correlacionados entre si. Houve bom ajuste do progresso da doença ao modelo monomolecular. As menores taxas de crescimento foram obtidas no tratamento com poda e aplicação de fungicida mensal. O tratamento que combinou poda e pulverização com fungicida apresentou diferença significativa na redução do percentual de frutos com vassoura. Os genótipos NO-34, NO-17 e NO-02 foram os que apresentaram menores percentagens de frutos com vassoura, sendo significativamente diferentes dos genótipos NO-24 e NO-13. / Witches' broom is the most important disease of cocoa, in the countries where it occurs. In 1989, it was verified for the first time the presence of the pathogen in the main producing area of Brazil. The lack of efficient control measures resulted, in the last years, in losses in the production, changes in the use of the soil, sale of properties, decrease of the employment level and damages to the environment. In view of the little knowledge on epidemic aspects of the disease in the conditions of the southeast of Bahia, the present work was elaborated with the following objectives: to study the gradient of the witches' broom infection in flushes and pods in grafted cocoa; to compare the effect of genotypes and three treatments (half-yearly phytosanitation, monthly phytosanitation and monthly phytosanitation allied to fungicide application) in the control of the disease; to study the witches' broom temporal progress, quantified in flushes and pods. Trials were carried out in Uruçuca, BA, in area contends 16 different genotypes, adjacent an area with abandoned cocoa with high incidence of the disease. The experimental area was divided in three parts, which received the following treatments: half-yearly phytosanitation, monthly phytosanitation and monthly phytosanitation allied to fungicide application. At least once a month, flushes and pods with broom were counted. Results showed the absence of clear evidence of the existence of disease gradient. The levels of genetic resistance to the witches' broom of flushes and pods were not correlated to each other. There was good adjustment of progress of the disease to the monomolecular model. The smallest growth rates were obtained in the treatment with monthly phytosanitation and fungicide application. The treatment that allied phytosanitation and fungicide application presented significant difference in the reduction of the percentage of witches' broom infected pods. The genotypes NO-34, NO-17 and NO-02 presented smaller percentages of diseased pods, being significantly different from the genotypes NO-24 and NO-13.
35

Identificação molecular de fitoplasmas associados ao amarelo da abobrinha-de-moita e à filodia de frutos do morangueiro / Molecular identification of phytoplasmas associated with summer squash yellow and strawberry fruit phyllody

Melo, Luciano de Aquino 13 March 2009 (has links)
Frequentemente, fitoplasmas têm sido associados com doenças em cucurbitáceas, tanto cultivadas, como silvestres e daninhas. Em abobrinha-de-moita cultivada no Vale do Ribeira, Estado de São Paulo, foi observado superbrotamento de hastes, malformação da parte aérea e folhas deformadas e enrugadas, sugerindo uma possível infecção por fitoplasmas. A associação de fitoplasmas com morangueiro parece ser rara no Brasil. No entanto, nos municípios de Domingos Martins e Santa Maria de Jetibá, Estado do Espírito Santo, foram observadas plantas de morango apresentando expressiva filodia de frutos, sintoma suspeito de infecção por fitoplasmas. O presente trabalho teve por objetivos detectar e identificar molecularmente os possíveis fitoplasmas associados às plantas doentes. O DNA total das amostras, extraído com um kit comercial ou pelo protocolo 2X CTAB, foi amplificado por dupla PCR com os primers universais P1/Tint e R16F2n/R16R2. Os produtos amplificados com o primeiro par de primers foram reamplificados usando os pares R16(I)F1/R16(I)R1 e R16(III)F2/R16(III)R1, visando a identificação e os produtos de dupla PCR, amplificados com o segundo par de primers, utilizados na análise por RFLP e no sequenciamento. Para as análises filogenéticas adotaram-se seqüências nucleotídicas de fitoplasmas pertencentes a diversos grupos. Observações feitas ao microscópio eletrônico de transmissão revelaram a presença de corpúsculos pleomórficos típicos de fitoplasmas no floema de morangueiro. Por dupla PCR com os primers universais, foi consistentemente detectada a presença de fitoplasmas nos tecidos das plantas doentes. Com o uso dos primers específicos foi possível a identificação de um fitoplasma afiliado ao grupo 16SrIII em abobrinha-de-moita e de fitoplasmas afiliados aos grupos 16SrI e 16SrIII em morangueiro. A análise por RFLP confirmou os resultados obtidos com os primers específicos e demonstrou a presença de um fitoplasma afiliado ao grupo 16SrXIII nas amostras de morangueiro. O sequenciamento permitiu a obtenção de duas seqüências a partir das amostras de morangueiro. A primeira seqüência nucleotídica, SFP-Br1 (EU719107), apresentou 99% de similaridade com as seqüências dos fitoplasmas afiliados ao grupo 16SrIII e a análise filogenética mostrou um maior relacionamento com o subgrupo 16SrIII-B. A segunda seqüência nucleotídica, SFP-Br-3 (EU719109), apresentou 98% de similaridade com as seqüências dos fitoplasmas afiliados ao grupo 16SrXIII. A análise filogenética mostrou este fitoplasma como um representante do grupo 16SrXIII, porém localizado em um novo ramo, diverso daqueles conhecidos para representantes deste grupo. Os coeficientes de similaridade calculados para SFP-Br3 e para os subgrupos 16SrXIII-A, 16SrXIII-B e 16SrXIII-C variaram de 0,91 a 0,96, o que distinguiu o fitoplasma presente no morangueiro dos outros subgrupos de fitoplasmas afiliados ao grupo 16SrXIII já existentes. Assim, através de análise molecular, foi possível relatar a abobrinha-de-moita como um novo hospedeiro de fitoplasmas do grupo 16SrIII, bem como detectar e identificar distintos fitoplasmas nas plantas de morango, inclusive um novo representante, aqui denominado de 16SrXIII-D. / Phytoplasmas have been associated with some diseases of cucurbit as cultivated as sylvester and weed species. Symptoms of witches broom and leaf malformation were observed in summer squash cultivated in the Vale do Ribeira, São Paulo State, suggesting infection by phytoplasma. The association of phytoplasmas with strawberry diseases seems to be rare in Brazil. Nevertheless, in Domingos Martins and Santa Maria de Jetibá cities, located in Espirito Santo State, strawberries plants with expressive fruit phyllody were observed. This kind of symptom also suggested infection associated to phytoplasma. So, the present work was conducted in order to detect and identify possible phytoplasmas associated to simptomatic plants through molecular analysis. The DNA, extracted with a commercial kit or through 2X CTAB protocol, was amplified by nested PCR with universal primers P1/Tint and R16F2n/R16R2. The amplified products with the first primers pairs were reamplified using the primers R16(I)F1/R16(I)R1 and R16(III)F2/R16(III)R1 for specific identification; and the products of nested PCR, amplified from second primers pair, were submitted to RFLP analysis and to sequencing. For phylogenetic analysis were included sequences of phytoplasmas belonging to many groups. Results showed that pleomorphic bodies were present in the phloem of diseased strawberries plants, by using electronic microscopy. The amplifications by nested PCR with universal primers allowed the detection of phytoplasmas in the tissues of symptomatic strawberry and squash plants. PCR assays with specific primers revealed a phytoplasma of 16SrIII group in summer squash and phytoplasmas of 16SrI and 16SrIII groups in strawberry plants. RFLP analysis confirmed the occurrence of a member of 16SrIII group in summer squash and demonstrated the presence of phytoplasmas affiliated to 16SrI, 16SrIII and 16SrXIII groups in strawberry samples. The sequencing allowed the attainment of two sequences from strawberries samples. The first sequence, designated SFP-Br1 (EU719107) representing a phytoplasma affiliated to 16SrIII group, showed 99% of similarity with other sequences of phytoplasmas affiliated with this group. The phylogenetic analysis showed that this phytoplasma was more related with the subgroup 16SrIII-B. The second sequence, designated SFP-Br3 (EU719109) representing a phytoplasma affiliated to 16SrXIII group, showed 98% of similarity with members of this group. The phylogenetic analysis revealed this phytoplasma belonging to 16SrXIII group, but located on a new different branch from those previously known. The similarity coefficient indicated variations between SFP-Br3 and the three phytoplasmas affiliated to 16SrXIII-A, 16SrXIII-B and 16SrXIII-C sub-groups, varying on 0.91 to 0.96, distinguishing the strawberry phytoplasma from the other sub-groups of phytoplasma affiliated with the 16SrXIII group already existing. This way, through molecular analysis, it was possible to relate summer squash as a new host of 16SrIII group phytoplasma, as well as detecting and identifying distinct phytoplasmas on strawberry plants and characterize a new 16SrXIII-D subgroup.
36

THE ECOLOGY OF DISTURBANCES AND GLOBAL CHANGE IN THE MONTANE GRASSLANDS OF THE NILGIRIS, SOUTH INDIA

Srinivasan, Madhusudan P. 01 January 2011 (has links)
Biodiversity rich regions worldwide face threats from various global change agents. This research quantifies environmental influences on vegetation, and the impacts of exotic woody plant invasion and anthropogenic nitrogen (N) deposition in a global biodiversity hotspot. The study was conducted in the montane grasslands of the Nilgiris, Western Ghats, and outlines potential management options for this region. Specifically, I examined (1) the role of environmental factors in influencing native plant distribution and ecosystem properties, (2) the status and impact of exotic shrub (Scotch broom, henceforth broom) invasion, (3) the role of disturbances in the success of broom, (4) the role of fire in restoring invaded grasslands, and (5) the impacts of terrestrial N loading on the grassland ecosystem. I used experiments and surveys to assess these. Distributions of several key species were explained by a few complex environmental gradients. In invaded-grasslands, broom populations consisted mainly of intermediate size and age classes, with no clear indication of population decline. Invasion negatively impacted plant community structure and drastically changed composition, favoring shade-tolerant and weedy species. However, invasion did not greatly alter ecosystem function. Fire successfully eliminated mature broom stands, but resulted in a short-term increase in broom seedling recruitment. At the end of 18 months, the fire effects on uninvaded-grasslands were not apparent, but there was no conclusive evidence of the formerly invaded patches attaining the composition of uninvaded-grasslands following burning. N fertilization strongly influenced soil N dynamics, and shoot N concentrations, but effects on aboveground production were weak. Surprisingly, N enrichment had positive effects on diversity in the short-term. It is clear that these grasslands need immediate management intervention to forestall degradation from invasion. Fire could be used to eliminate mature broom stands and deplete persistent seedbanks, which will facilitate colonization by shade-intolerant grassland plants. Active restoration should be mindful of environmental preferences of framework species. Long-term studies of the impacts of N deposition in the context of disturbances will help determine realistic critical thresholds and utilize disturbances to buffer the potential adverse effects of increasing N loading.
37

Comparative Ecology and Conservation of Rare Native Broom, Carmichaelia (Fabaceae), South Island, New Zealand

Gruner, Ingrid Gerda January 2003 (has links)
Using a comparative approach, the presented study explores the ecology of ten species of native New Zealand broom, Carmichaelia, and their vulnerability to competition and herbivory, with the aim of gaining a better understanding of the significance of introduced species as a threat to rare indigenous plants in New Zealand. In particular, the study focuses on the relationship between characteristics of the Carmichaelia species and their vulnerability, as well as on other factors influencing the significance of introduced species as a threat. To gain a better understanding of the ecology of the Carmichaelia species, their current habitats and associated plant communities were investigated using quantitative-descriptive methods in the field. The effect of competition with introduced plants was studied in two glasshouse experiments, differentiating above ground competition for light from below ground competition for nutrients and water. The experiments focussed on the early life-stage of seedling establishment of the Carmichaelia species. The impact of herbivory by introduced mammals was studied in four field-based exclosure trials, focussing on the effects on survival and reproductive activity of adult Carmichaelia plants. The results showed that the effects of competition and herbivory vary between the different species. Furthermore, they provided a set of species characteristics that can be used as indicators to predict the vulnerability of Carmichaelia to the impact of introduced species. These indicators provide a useful tool for threatened species management, as they allow the identification of the most vulnerable species as well as the most significant threat to each species. Furthermore, the indicators can be used to group species, combining those with similar vulnerability profiles, and therefore, likely similar management needs. However, the example of the Carmichaelia species also illustrated that the use of indicators for the vulnerability of threatened species is limited and needs to be combined with case-by-case studies to verify the actual significance of threats for each population of concern. The vulnerability profiles derived from species’ characteristics can be used to guide such site specific studies, ensuring they focus on the most relevant threat factors. This combination of the understanding of general patterns in the vulnerability of species with targeted species and site-specific studies will lead to increased efficiency in the conservation management of threatened plant species.
38

Controle biológico de Moniliophthora perniciosa, agente causal da vassoura de bruxa do cacaueiro, por diferentes espécies e linhagens de Trichoderma spp

Simões, Maria Lúcia Garcia [UNESP] 25 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-25Bitstream added on 2014-06-13T20:04:39Z : No. of bitstreams: 1 simoes_mlg_dr_rcla.pdf: 7383499 bytes, checksum: 3bdb988e95e0edaf3bc9450a229443f5 (MD5) / Diferentes isolados de Trichoderma (T. stromaticum, T. pseudokoningii, T. harzianum, e T. viride) e um isolado de T. atroviride, T. longibrachiatum, T. virens e T. pilulliferum foram estudados para uso no biocontrole de quatro subgrupos genéticos de Moniliophthora perniciosa, designados como Mp1441, Mp1445, Mp1893 e Mp1916. A associação das características dos isolados de Trichoderma avaliados quanto à velocidade de crescimento micelial, germinação, produção de esporos e produtividade massal de esporos em arroz, além das suas capacidades de antibiose e micoparasitismo a cada subgrupo do patógeno, resultou na determinação do índice denominado Potencial para uso no biocontrole (%PCB) a cada subgrupo de M. perniciosa. Os %PCBs variaram, demonstrando haver variabilidade genética entre os isolados do antagonista quanto às características avaliadas, como também nos níveis de resistência do patógeno. T. harzianum 911 apresentou o melhor %PCB para todos os subgrupos de M. perniciosa, sendo o pior apresentado por T. reesei 1612. Mp1445 foi o subgrupo que apresentou a menor capacidade de supressão aos antagonistas, sendo a maior apresentada por Mp1916. T. harzianum 906 inibiu o crescimento de Mp1916 por metabólitos não voláteis e todos os isolados de Trichoderma avaliados inibiram todos os subgrupos do patógeno pela ação de metabólitos voláteis, variando, porém, os percentuais de inibição entre as espécies e entre isolados da mesma espécie. Mp1445 inibiu o crescimento de T. virens 2007 por metabólitos não voláteis, sendo comprovada, portanto, a possibilidade do patógeno inibir o antagonista. T. harzianum 911 apresentou capacidade de micoparasitismo em placa e em vassouras infectadas individualmente pelos subgrupos do patógeno, além de produzir as enzimas β-1,3-glucanase, quitinase, protease, FPase, CMCase e amilase, tanto em substratos específicos como em cultivos... / Different isolates of Trichoderma (T. stromaticum, T. pseudokoningii, T. harzianum and T. viride) and one isolate of T. atroviride, T. longibrachiatum, T. virens e T. pilulliferum were studied for their usage in biocontrol of four genetic subgroups of Moniliophthora perniciosa named as Mp1441, Mp1445, Mp1893 e Mp1916. The association of the characteristics of the Trichoderma isolates evaluated regarding to velocity of mycelial growth, germination, spores production in Petri dish and mass production of spores in rice, besides their capacities of antibiosis and mycoparasitism to each subgroup of the pathogen, resulted in the determination of the index named Potential to be used in Biocontrol (%PCB) to each subgroup of M. perniciosa. The %PCBs varied, pointing out that there is a genetic variability among the antagonistic isolates regarding to the evaluated characteristics, as well as the levels of the pathogen resistance. T. harzianum 911 showed the best %PCB for all subgroups of M. perniciosa, being the worst presented by T. reesei 1612. Mp1445 was the subgroup that presented the lowest antagonistic suppression capacity, being the highest presented by Mp1916. T. harzianum 906 inhibited the growth of Mp1916 by non-volatile metabolites and all the evaluated isolates of Thrichoderma inhibited all the subgroups through volatile metabolites, varying, although, the percentages of inhibition among the species and among the isolates of the same species. Mp1445 inhibited the growth of T. virens 2007 by non-volatile metabolites, being proved, therefore, the possibility of the pathogen to inhibit the antagonist. T. harzianum 911 presented the mycoparasitism capacity in Petri dishes and in brooms infected indiviadually by the pathogen, besides the production of β-1,3-glucanase, chitinase, protease, FPase, CMCase and amilase, in both specific substrates and in cultivations with dried mycelia... (Complete abstract click electronic access below)
39

POTENCIAL ANTIPROLIFERATIVO, ANTIGENOTÓXICO E ANÁLISE FITOQUÍMICA DOS EXTRATOS AQUOSOS E DO ÓLEO DE Baccharis dracunculifolia DC. (Asteraceae) / ANTIPROLIFERATIVE POTENTIAL, ANTIGENOTOXIC AND PHYTOCHEMICAL ANALYSIS OF AQUEOUS EXTRACTS AND OIL OF Baccharis dracunculifolia DC. (Asteraceae)

Pasqualli, Marina 29 July 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Baccharis dracunculifolia is a medicinal species, popularly known as broom, and has its use based on the preparation of infusions of leaves for the treatment of gastric disorders, physical fatigue, lack of appetite, fever diseases and organic weakness. Its essential oil stands out in the perfumery industry as well as in biological studies. The study aimed to evaluate the potential antiproliferative, genotoxic and antigenotoxic of two populations of B. dracunculifolia on the test systems Allium cepa L. and Lactuca sativa L. as well as performs the phytochemical analysis of the aqueous extract and oil obtained from the leaves. The material used in the preparation of infusions and oil consisted of two populations collected in Santa Maria (SM) and São Pedro do Sul (SPS), which part was dehydrated to prepare infusions in 5g.L-1 and 10g.L -1 concentrations, and the other part was frozen for later extraction of essential oil. To determine the antiproliferative, genotoxic and antigenotoxic activities, the effects of aqueous extracts and oil on the A. cepa test and L. sativa systems. The experiment whith A. cepa consisted of twelve groups of four bulbs, each group corresponding to a treatment. The bulbs were rooted in water an than subjected to treatments for 24 hours. The experiment whith L. sativa consisted of nine groups of four Petri dishes. Each plate was soacked whith about 7 mL of extract, which were in contact with the seeds for 72 hours. After this period the roots of A. cepa and L. sativa seeds were collected, fixed in Carnoy 3:1 and stored in refrigerated in 70% ethanol until the preparation of the slides. The determination of phenolic compounds from aqueous extracts was performed by the High Performance Liquid Chromatography (HPLC). The compounds of the essential oil were determined by Gas Chromatography (GC). The genotoxicity data were subjected to analysis Chi-square test, whereas the data of the chromatographic analysis were subjected to Tukey test (p <0.05). The results of the A. cepa test showed that extracts from B. dracunculifolia have antiproliferative and antigenotoxic potential as well as the essential oil of the SPS population, while the oil SM population induces cell proliferation. For L. sativa test, aqueous extracts of the two populations demonstrated atiproliferativo effect, except the aqueous extract of SPS population at a concentration of 10 g.L-1, in which there was an increase in cell proliferation. Chromatographic analysis indicated as major compounds, p-coumaric acid to the aqueous extracts and E-nerolidol to the essential oil. / Baccharis dracunculifolia DC. é uma espécie medicinal, conhecida popularmente como vassourinha, e tem sua utilização baseada no preparo de infusões das folhas para o tratamento de distúrbios gástricos, cansaço físico, inapetência, afecções febris e debilidade orgânica. Seu óleo essencial se destaca na indústria de perfumaria, bem como em estudos biológicos. O trabalho teve por objetivos avaliar o potencial antiproliferativo, genotóxico e antigenotóxico de duas populações de B. dracunculifolia sobre os sistemas teste de Allium cepa L. e Lactuca sativa L., bem como realizar a análise fitoquímica do extrato aquoso e do óleo obtidos a partir das folhas. O material utilizado no preparo das infusões e do óleo constou de duas populações coletadas em Santa Maria (SM) e São Pedro do Sul (SPS), do qual parte foi desidratado para preparo das infusões nas concentrações 5g.L-1 e 10g.L-1 e outra parte foi congelada para posterior extração do óleo essencial. Para determinação das atividades antiproliferativa, genotóxica e antigenotóxica, foi avaliado o efeito dos extratos aquosos e do óleo sobre os sistemas teste de A. cepa e L. sativa. O experimento com A. cepa constou de doze grupos de quatro bulbos, cada grupo correspondendo a um tratamento. Os bulbos foram enraizados em água e posteriormente submetidos aos tratamentos por 24 horas. O experimento com L. sativa constou de nove grupos de quatro placas de Petri, cada grupo correspondendo a um tratamento, onde foram dispostas 50 sementes por placa. Cada placa foi embebida com aproximadamente 7 mL de extrato, os quais ficaram em contato com as sementes por 72 horas. Após esse período as raízes de A. cepa e as sementes de L. sativa foram coletadas, fixadas em Carnoy 3:1 e armazenadas sob refrigeração em etanol 70% até o preparo das lâminas. A determinação dos compostos fenólicos presentes nos extratos aquosos foi realizada pela técnica de Cromatografia Líquida de Alta Eficiência (CLAE). Os compostos do óleo essencial foram determinados pela técnica de Cromatografia Gasosa (CG). Os dados obtidos da análise de genotoxicidade foram submetidos ao teste Qui-quadrado, enquanto que, os dados da análise cromatográfica foram submetidos ao teste de Tukey (p<0,05). Os resultados do teste de A. cepa demonstraram que os extratos de B. dracunculifolia possuem potencial antipoliferativo e antigenotóxico, bem como o óleo essencial da população de SPS, enquanto que o óleo da população SM induziu a proliferação celular. Para o teste de L. sativa, os extratos aquosos das duas populações demonstraram efeito antiproliferativo, com exceção do extrato aquoso da população SPS na concentração de 10 g.L-1, no qual houve um aumento da proliferação celular. As análises cromatográficas indicaram como compostos majoritários, o ácido p-cumárico para os extratos aquosos e o E-nerolidol para o óleo essencial.
40

Controle biológico de Moniliophthora perniciosa, agente causal da vassoura de bruxa do cacaueiro, por diferentes espécies e linhagens de Trichoderma spp /

Simões, Maria Lúcia Garcia. January 2010 (has links)
Resumo: Diferentes isolados de Trichoderma (T. stromaticum, T. pseudokoningii, T. harzianum, e T. viride) e um isolado de T. atroviride, T. longibrachiatum, T. virens e T. pilulliferum foram estudados para uso no biocontrole de quatro subgrupos genéticos de Moniliophthora perniciosa, designados como Mp1441, Mp1445, Mp1893 e Mp1916. A associação das características dos isolados de Trichoderma avaliados quanto à velocidade de crescimento micelial, germinação, produção de esporos e produtividade massal de esporos em arroz, além das suas capacidades de antibiose e micoparasitismo a cada subgrupo do patógeno, resultou na determinação do índice denominado Potencial para uso no biocontrole (%PCB) a cada subgrupo de M. perniciosa. Os %PCBs variaram, demonstrando haver variabilidade genética entre os isolados do antagonista quanto às características avaliadas, como também nos níveis de resistência do patógeno. T. harzianum 911 apresentou o melhor %PCB para todos os subgrupos de M. perniciosa, sendo o pior apresentado por T. reesei 1612. Mp1445 foi o subgrupo que apresentou a menor capacidade de supressão aos antagonistas, sendo a maior apresentada por Mp1916. T. harzianum 906 inibiu o crescimento de Mp1916 por metabólitos não voláteis e todos os isolados de Trichoderma avaliados inibiram todos os subgrupos do patógeno pela ação de metabólitos voláteis, variando, porém, os percentuais de inibição entre as espécies e entre isolados da mesma espécie. Mp1445 inibiu o crescimento de T. virens 2007 por metabólitos não voláteis, sendo comprovada, portanto, a possibilidade do patógeno inibir o antagonista. T. harzianum 911 apresentou capacidade de micoparasitismo em placa e em vassouras infectadas individualmente pelos subgrupos do patógeno, além de produzir as enzimas β-1,3-glucanase, quitinase, protease, FPase, CMCase e amilase, tanto em substratos específicos como em cultivos...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Different isolates of Trichoderma (T. stromaticum, T. pseudokoningii, T. harzianum and T. viride) and one isolate of T. atroviride, T. longibrachiatum, T. virens e T. pilulliferum were studied for their usage in biocontrol of four genetic subgroups of Moniliophthora perniciosa named as Mp1441, Mp1445, Mp1893 e Mp1916. The association of the characteristics of the Trichoderma isolates evaluated regarding to velocity of mycelial growth, germination, spores production in Petri dish and mass production of spores in rice, besides their capacities of antibiosis and mycoparasitism to each subgroup of the pathogen, resulted in the determination of the index named Potential to be used in Biocontrol (%PCB) to each subgroup of M. perniciosa. The %PCBs varied, pointing out that there is a genetic variability among the antagonistic isolates regarding to the evaluated characteristics, as well as the levels of the pathogen resistance. T. harzianum 911 showed the best %PCB for all subgroups of M. perniciosa, being the worst presented by T. reesei 1612. Mp1445 was the subgroup that presented the lowest antagonistic suppression capacity, being the highest presented by Mp1916. T. harzianum 906 inhibited the growth of Mp1916 by non-volatile metabolites and all the evaluated isolates of Thrichoderma inhibited all the subgroups through volatile metabolites, varying, although, the percentages of inhibition among the species and among the isolates of the same species. Mp1445 inhibited the growth of T. virens 2007 by non-volatile metabolites, being proved, therefore, the possibility of the pathogen to inhibit the antagonist. T. harzianum 911 presented the mycoparasitism capacity in Petri dishes and in brooms infected indiviadually by the pathogen, besides the production of β-1,3-glucanase, chitinase, protease, FPase, CMCase and amilase, in both specific substrates and in cultivations with dried mycelia... (Complete abstract click electronic access below) / Orientador: Sâmia Maria Tauk-Tornisielo / Coorientador: Givaldo Rocha Niella / Banca: Antonio Carlos Monteiro / Banca: Iracema Helena Schoenlein-Crusius / Banca: Sandra Regina Ceccato Antonini / Banca: Carlos Renato Corso / Doutor

Page generated in 0.0405 seconds