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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

Peeling, gluing and bonding characteristics of Nigerian plantation-grown Gmelina arborea (Roxb.)

Badejo, Solomon Olufunmilayo Olubunmi January 1977 (has links)
The gluing properties of plantation-grown gmelina wood (Gmelina arborea Roxb.) from Nigeria were investigated. Three wood peeling temperatures - 20°C, 50°C and 85°C; two glue types - urea-formaldehyde (UF) and phenol-formaldehyde (PF); two glue spreads - 25 kg/MDGL (55 lb) and 32 kg/MDGL (70 lb); and two closed assembly times - 10 minutes and 20 minutes were used. Veneers from the sample logs were peeled tight and were 1.27 mm (0.05 in) thick. The specific gravity for the logs was determined and its influence on the probable end uses of gmelina plywood discussed. Three 5-ply plywood panels were made, for each treatment combination for 72 in all. A total of 1438 shear test specimens were used. The UF specimens were tested dry and after vacuum-pressure treatment whereas the PF specimens received vacuum-pressure and boil-dry-boil tests. Bond quality was evaluated on the basis of wood shear strength and percentage wood failure. Results were compared to the U.S., British and German Plywood Standards. Wood peeling temperature was highly significant regardless of glue type and bond quality testing method. Heating of gmelina logs prior to peeling did not improve veneer peel-quality. Veneers were of the highest peel-quality (basis: Thickness variation and surface roughness) when logs were peeled at 20°C. The highest peeling temperature yielded the lowest peel-quality. Bond quality, (percentage wood failure), was consistently reduced by increasing peeling temperature and was lowest at 85°C in all the UF and PF treatments, regardless of bond quality testing method. Ignoring glue spreads, panels made from veneers cut at temperatures of 50°C and 85°C gave the highest shear strength values among the UF treatments. On the other hand, panels from veneers cut at temperatures of 20°C and 85°C gave the highest shear strength values among the PF treatments. All factors considered, treatment combination of Spread 55 - Time 20, arising from veneers cut at the control temperature of 20°C, gave an impressive bond quality in all the UF and PF treatments used. Five of the 12 PF treatments used, regardless of type of bond quality testing method, pass the U.S. Plywood Standard; one passes the British Standard; while all pass the German Standard. On the other hand, five of the 12 UF treatments from vacuum-pressure test pass the U.S. Standard; two pass the British Standard; while all pass the German Standard. Furthermore, all the 12 UF treatments from dry test pass the U.S. Standard; six pass the British Standard; while all pass the German Standard. From the results obtained, plantation-grown Gmelina arborea wood from Nigeria, with a specific gravity of 0.41 ± 0.027 (as determined), was found suitable for use as construction plywood, core and crossband veneer for decorative panel as well as container veneer and plywood. The dominant factor accounting for the general trend of low percentage wood failure was attributed to veneer surface inactivation, resulting from surface aging of veneers. / Forestry, Faculty of / Graduate
2

Ecology of Bryobia arborea (M & A) and Tetranychus urticae (Koch) in South Australian apple orchards /

Lamacraft, Lesley Beryl. January 1972 (has links) (PDF)
Thesis (B.Sc.(Hons.)) -- University of Adelaide, Dept. of Entomology, 1972.
3

Isolement et caractérisation des saponosides de trois plantes de la famille des araliaceae et dracaenaceae et évaluation de leurs activités cytotoxiques sur cellules tumorales / Isolation and caracterisation of saponins from three plants of Araliaceae and Dracaenaceae families and evaluation of their cytotoxic activities on tumoral cells

Kougan Nkwokap, Guy Beddos 20 September 2010 (has links)
L’intérêt des substances d’origine naturelle, potentiellement anti-tumorales nous a amené à nous intéresser aux saponines triterpéniques et stéroïdiques de plantes issues de la biodiversité africaine de la famille des Araliaceae et des Dracaenaceae. En effet, des études antérieures menées sur quelques plantes de ces deux familles ont conduit à l’obtention de molécules complexes et originales possédant d’excellentes propriétés cytotoxiques, immuno-modulatrices, anti-inflammatoires. Au vu de ces résultats nous avons entrepris des investigations pharmaco-chimiques sur Cussonia arborea (Araliaceae), Dracaena deisteliana et Dracaena arborea (Dracaenaceae), plantes médicinales couramment utilisées en pharmacopée traditionnelle africaine pour traiter différentes maladies. Les travaux menés ont conduit à l’isolement de 31 composés purs en utilisant les différentes techniques analytiques du laboratoire notamment les diverses techniques de chromatographie liquide successive à pression atmosphérique, moyenne pression et flash chromatographie sur silice en phase normale et en phase inverse. Les structures ont été déterminées par les méthodes de spectrométrie de masse en source FAB et de spectroscopie de RMN 1D et 2D (COSY, TOCSY, NOESY, HMBC et HSQC). Parmi les 07 composés purs obtenus des écorces de Cussonia arborea, 5 sont des nouvelles saponines triterpéniques dont un dérivé de l’acide ursolique, un dérivé de l’hédéragénine et trois dérivés de l’acide oléanolique, tous disubstitués en position 3 et 28 par des chaînes oligosaccharidiques. 13 composés purs sont obtenus à partir des feuilles de Cussonia arborea, dont 7 nouvelles saponines triterpéniques dérivés de l’acide ursolique, de l’acide 23-hydroxyursolique, de l’hédéragénine et de l’acide oléanolique dont 04 d’entre elles sont obtenues sous forme de mélanges inséparables d’isomères acide oléanolique/acide ursolique et hédéragénine/acide 23-hydroxyursolique. A partir des écorces de Dracaena arborea et des tiges de Dracaena deisteliana, nous avons isolé et caractérisé 10 saponines stéroïdiques dont 4 nouvelles et une sapogénine. Les activités de certains de ces produits purs ont été évaluées sur deux lignées de cellules cancéreuses coliques humaines HCT 116 et HT-29. / The interest of the substances from natural origin, potentially antitumor led us to interest in triterpenoid and steroidal saponins of plants from the African biodiversity belonging to the Araliaceae and Dracaenaceae families of plants. Indeed, of the former studies undertaken on some plants of these two families led to obtaining complex and original molecules having excellent cytotoxic, immuno-modulating, anti-inflammatory properties. Within sight of these results we undertook pharmaco-chemical investigations on Cussonia arborea (Araliaceae), Dracaena deisteliana, and Dracaena arborea (Dracaenaceae), medicinal plants usually used in african traditional pharmacopeia to treat various diseases. The work led to the isolation of 31 pure compounds by using the various analytical techniques in particular the various chromatography techniques (CC, MPLC, TLC, flash) on silica gel, normal and reversed phases. The structures were determined by the methods of mass spectrometry (FAB, ESI, IE) and 1D (1H and 13C) and 2D (COSY, TOCSY, NOESY, HMBC and HSQC) NMR spectroscopy. Among the 07 pure compounds obtained of the barks of Cussonia arborea, 5 are new triterpenoid saponins derivatives of ursolic acid, hederagenin and three derived from the acid oleanolic, all disubstituted in position 3 and 28 by oligosaccharidic chains. 13 pure compounds were obtained from leaves of Cussonia arborea, seven of which are new triterpenoid saponins derivatives of oleanolic acid, ursolic acid, hederagenin and 23-hydroxyursolic acid of which four were obtained as mixtures of isomers oleanolic acid/ursolic acid and hederagenin/23-hydroxyursolic acid. From the bark of Dracaena arborea and stem of Dracaena deisteliana, we isolated and characterized ten steroidal saponins including 4 new and sapogenin. The activities of some of these pure products were evaluated on two cancerous lines human colic cells HCT 116 and HT-29.
4

Stand structure development effects on wood quality of Melina (Gmelina arborea roxb.)

Gonzalez Rubio, Hector Larsen, David R. January 2009 (has links)
Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 15, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. David Larsen Vita. Includes bibliographical references.
5

Etude Phytochimique de Plantes Médicinales des Andes Vénézuéliennes : Zanthoxylum rhoifolium LAM (Rutaceae) et Bulnesia arborea Cl. Gay (Zygophyllaceae) / Phytochemical Study of Medicinal Plants from the Venezuelan Andes : Zanthoxylum rhoifolium LAM (Rutaceae) and Bulnesia arborea Cl. Gay (Zygophyllaceae)

Santiago Brugnoli, Laura Vanessa 22 July 2011 (has links)
Ces travaux de thèse concernent l’étude phytochimique de deux plantes médicinales appartenant aux genres Zanthoxylum (Rutaceae) et Bulnesia (Zygophyllaceae) connus pour leur utilisation en médecine traditionnelle, et plus particulièrement deux espèces endémiques des Andes Vénézuéliennes : Z. rhoifolium LAM et B. arborea Cl. Gay. L’étude des feuilles et des tiges de ces deux plantes a conduit à l’isolement de dix composés purs et complètement caractérisés : sept sont nouveaux (e.g., l’alcaloïde zanthoxyfoline, des saponines de types triterpène et ergostane) et l’un d’entre eux présente un squelette sesquiterpénique jusqu’alors jamais décrit (i.e., le bulnéarboréanoside I). / This work is a phytochemical study of two medicinal plants belonging to the genera Zanthoxylum (Rutaceae) and Bulnesia (Zygophyllaceae), which are known for their use in folk medecine, and in particular two endemic species of the Venezuelan Andes: Z. rhoifolium LAM and B. arborea Cl. Gay. The study of leaves and stems of these two plants led to the isolation of ten pure and fully characterized compounds: seven are new natural products (e.g., the alkaloid zanthoxyfoline, triterpene- and ergostane-types saponins) and one of them presents a sesquiterpene skeleton hitherto ever described (i.e., le bulnearboreanoside I).
6

Caracterização tecnológica da madeira das espécies de maior frequência no segundo ciclo de corte na Floresta Nacional do Tapajós / Lumber technological characteristics of the more frequent species at second exploration cycle in the Tapajós National Forest

Cardoso, Cláudia da Costa 28 January 2015 (has links)
Ensaios pioneiros sobre o manejo de florestas tropicais, no final da década de 70, foram executados na Floresta Nacional (FLONA) do Tapajós; e atualmente surge a oportunidade de se iniciar os estudos relativos ao segundo ciclo de corte. Nisto, áreas experimentais em que a exploração inicial foi intensiva apresentam mudanças na cobertura vegetal, com abundância de espécies menos conhecidas ou não comerciais, sendo então necessário analisar tecnologicamente a madeira dessas espécies com o intuito de inseri-las no mercado. Visando colaborar nesse sentido, o presente trabalho teve como objetivo principal caracterizar tecnologicamente e elaborar programas de secagem para as madeiras de Acariquarana (Rinorea guianensis), Breu (Protium apiculatum) e Urucu da mata (Bixa arborea); espécies com alta densidade populacional na área do segundo ciclo de corte na FLONA Tapajós. Para tal, abateu-se cinco árvores de cada espécie, sendo coletado material tanto para a identificação botânica como para a caracterização anatômica, ensaios físico-mecânicos e elaboração dos programas de secagem, além destes foram realizados testes estatísticos de correlação canônica para identificar as associações entre as características estudadas. Com base nos resultados, a madeira das espécies Rinorea guianensis e Protium apiculatum apresentaram características anatômicas semelhantes às encontradas em literatura ao nível de gênero e, Bixa arborea para o nível de espécie. Em relação às principais propriedades físico-mecânicas, as madeiras de Acariquarana, Breu e Urucu possuem densidade básica de, respectivamente, 0,78; 0,51 e 0,27 g/cm³; e com Módulo de Ruptura (MOR) na flexão estática de 147,98; 79,10 e 34,06 Mpa, na mesma ordem. Em comparação com espécies já comercializadas, a espécie Rinorea guianensis (Acariquarana) pode ser indicada para construção civil, móveis, ferramentas, além de torneados e chapas; a espécie Protium apiculatum (Breu) pode ser usada na construção civil, embalagens, caixas, venezianas, para decoração, móveis e compensados e, Bixa arborea (Urucu da mata) pode ser indicada para molduras, palito de fósforo, compensados, laminados, divisórias internas, engradados, brinquedos, aeromodelismo, além de produção de papel. Foi possível a indicação de programas de secagem específicos para as madeiras de cada uma das espécies estudadas, os quais se mostraram coerentes com as indicações encontradas em literatura para espécies já comercializadas e com características semelhantes às das espécies em estudo. Com relação à analise das correlações canônicas ao nível de 1% de probabilidade entre as propriedades das madeiras observa-se que madeiras de maior frequência e espessura do raio e parede celular de menor espessura estão associadas a madeiras de alta contração tanto tangencial como radial, e baixa densidade básica; madeiras de maior frequência e espessura do raio e com paredes menos espessas estão associadas a madeiras de elevado módulo de ruptura no ensaio de flexão estática e menor módulo de ruptura no ensaio de compressão paralela; madeiras com paredes mais espessas e menor espessura dos raios estão associadas a madeiras de maior módulo de ruptura no ensaio de compressão paralela e menor módulo de ruptura no ensaio de flexão estática; madeiras com raios mais espessos e parede menos espessa estão associados a madeiras de baixo nível de colapso e elevado nível de rachadura. / Pioneering trials on management of tropical forests, in the 70s, were executed in the Tapajós National Forest (FLONA); and presently appears the opportunity to begin the studies for the second cutting cycle. However, experimental areas where initial exploration was intensive present changes in the forest composition, with abundance of lesser-known or non commercial species; being necessary technological analysis of these species lumber to insert it in the market. In order to contribute in this direction, the present work aimed the technological characterization and the development of drying programs for woods of Acariquarana (Rinorea guianensis), Breu (Protium apiculatum) and Urucu da mata (Bixa arborea); species with high population density in areas of second cutting cycle in the Tapajós National Forest. For this, the material was collected for botanical identification and for anatomical characterization, physical and mechanical testing and development of drying programs. The wood of Acariquarana presents some distinct growth rings, straight grain, very large vessels, solitary to multiple, intervascular switches pit, garnished, long fibers with thick cell wall, not septate; Axial parenchyma scanty paratracheal, heterogeneous rays, multiseriate, numerous and the presence of parenchymatical crystals. The wood of Breu has distinct growth rings, crossed grain, big vessels, solitary to multiple, diffuse porosity, intervascular switches pit, garnished, medium-wall fibers, septate, paratracheal vasicentric axial parenchyma, heterogeneous rays, multiseriate, numerous. Wood of Urucu da mata presents distinct growth rings, straight grain, big vessels, diffuse porosity, intervascular switches pit, garnished, thin-walled fibers, septate, axial parenchyma diffuse apotracheal, storied rays, heterogeneous, multiseriates and numerous. Regarding the main physical and mechanical properties the wood of Acariquarana, Breu and Urucu have basic density of, respectively, 0,78; 0,51 and 0,27 g/cm³; and with Module of Rupture (MOR) in static bending of 147,98; 79,10 and 34,06 MPa, in the same order. Compared to species already marketed, Rinorea guianensis (Acariquarana) may be indicated for construction, furniture, tools, turned and plates; Protium apiculatum (Breu) may be used in construction, packages, boxes, blinds, decorating parts, furniture and plywood, and Bixa arborea (Urucu da mata) may be indicated for frames, safety match, plywood, laminates, crates, toys, model airplanes, as well to paper production. It was possible to indicate specific kiln schedules for each one of the studied species lumber, which demonstrated consistent with the information found in literature for species already on the market and with similar characteristics to the studied species.
7

Caracterização tecnológica da madeira das espécies de maior frequência no segundo ciclo de corte na Floresta Nacional do Tapajós / Lumber technological characteristics of the more frequent species at second exploration cycle in the Tapajós National Forest

Cláudia da Costa Cardoso 28 January 2015 (has links)
Ensaios pioneiros sobre o manejo de florestas tropicais, no final da década de 70, foram executados na Floresta Nacional (FLONA) do Tapajós; e atualmente surge a oportunidade de se iniciar os estudos relativos ao segundo ciclo de corte. Nisto, áreas experimentais em que a exploração inicial foi intensiva apresentam mudanças na cobertura vegetal, com abundância de espécies menos conhecidas ou não comerciais, sendo então necessário analisar tecnologicamente a madeira dessas espécies com o intuito de inseri-las no mercado. Visando colaborar nesse sentido, o presente trabalho teve como objetivo principal caracterizar tecnologicamente e elaborar programas de secagem para as madeiras de Acariquarana (Rinorea guianensis), Breu (Protium apiculatum) e Urucu da mata (Bixa arborea); espécies com alta densidade populacional na área do segundo ciclo de corte na FLONA Tapajós. Para tal, abateu-se cinco árvores de cada espécie, sendo coletado material tanto para a identificação botânica como para a caracterização anatômica, ensaios físico-mecânicos e elaboração dos programas de secagem, além destes foram realizados testes estatísticos de correlação canônica para identificar as associações entre as características estudadas. Com base nos resultados, a madeira das espécies Rinorea guianensis e Protium apiculatum apresentaram características anatômicas semelhantes às encontradas em literatura ao nível de gênero e, Bixa arborea para o nível de espécie. Em relação às principais propriedades físico-mecânicas, as madeiras de Acariquarana, Breu e Urucu possuem densidade básica de, respectivamente, 0,78; 0,51 e 0,27 g/cm³; e com Módulo de Ruptura (MOR) na flexão estática de 147,98; 79,10 e 34,06 Mpa, na mesma ordem. Em comparação com espécies já comercializadas, a espécie Rinorea guianensis (Acariquarana) pode ser indicada para construção civil, móveis, ferramentas, além de torneados e chapas; a espécie Protium apiculatum (Breu) pode ser usada na construção civil, embalagens, caixas, venezianas, para decoração, móveis e compensados e, Bixa arborea (Urucu da mata) pode ser indicada para molduras, palito de fósforo, compensados, laminados, divisórias internas, engradados, brinquedos, aeromodelismo, além de produção de papel. Foi possível a indicação de programas de secagem específicos para as madeiras de cada uma das espécies estudadas, os quais se mostraram coerentes com as indicações encontradas em literatura para espécies já comercializadas e com características semelhantes às das espécies em estudo. Com relação à analise das correlações canônicas ao nível de 1% de probabilidade entre as propriedades das madeiras observa-se que madeiras de maior frequência e espessura do raio e parede celular de menor espessura estão associadas a madeiras de alta contração tanto tangencial como radial, e baixa densidade básica; madeiras de maior frequência e espessura do raio e com paredes menos espessas estão associadas a madeiras de elevado módulo de ruptura no ensaio de flexão estática e menor módulo de ruptura no ensaio de compressão paralela; madeiras com paredes mais espessas e menor espessura dos raios estão associadas a madeiras de maior módulo de ruptura no ensaio de compressão paralela e menor módulo de ruptura no ensaio de flexão estática; madeiras com raios mais espessos e parede menos espessa estão associados a madeiras de baixo nível de colapso e elevado nível de rachadura. / Pioneering trials on management of tropical forests, in the 70s, were executed in the Tapajós National Forest (FLONA); and presently appears the opportunity to begin the studies for the second cutting cycle. However, experimental areas where initial exploration was intensive present changes in the forest composition, with abundance of lesser-known or non commercial species; being necessary technological analysis of these species lumber to insert it in the market. In order to contribute in this direction, the present work aimed the technological characterization and the development of drying programs for woods of Acariquarana (Rinorea guianensis), Breu (Protium apiculatum) and Urucu da mata (Bixa arborea); species with high population density in areas of second cutting cycle in the Tapajós National Forest. For this, the material was collected for botanical identification and for anatomical characterization, physical and mechanical testing and development of drying programs. The wood of Acariquarana presents some distinct growth rings, straight grain, very large vessels, solitary to multiple, intervascular switches pit, garnished, long fibers with thick cell wall, not septate; Axial parenchyma scanty paratracheal, heterogeneous rays, multiseriate, numerous and the presence of parenchymatical crystals. The wood of Breu has distinct growth rings, crossed grain, big vessels, solitary to multiple, diffuse porosity, intervascular switches pit, garnished, medium-wall fibers, septate, paratracheal vasicentric axial parenchyma, heterogeneous rays, multiseriate, numerous. Wood of Urucu da mata presents distinct growth rings, straight grain, big vessels, diffuse porosity, intervascular switches pit, garnished, thin-walled fibers, septate, axial parenchyma diffuse apotracheal, storied rays, heterogeneous, multiseriates and numerous. Regarding the main physical and mechanical properties the wood of Acariquarana, Breu and Urucu have basic density of, respectively, 0,78; 0,51 and 0,27 g/cm³; and with Module of Rupture (MOR) in static bending of 147,98; 79,10 and 34,06 MPa, in the same order. Compared to species already marketed, Rinorea guianensis (Acariquarana) may be indicated for construction, furniture, tools, turned and plates; Protium apiculatum (Breu) may be used in construction, packages, boxes, blinds, decorating parts, furniture and plywood, and Bixa arborea (Urucu da mata) may be indicated for frames, safety match, plywood, laminates, crates, toys, model airplanes, as well to paper production. It was possible to indicate specific kiln schedules for each one of the studied species lumber, which demonstrated consistent with the information found in literature for species already on the market and with similar characteristics to the studied species.
8

Tolerância aos metais pesados chumbo e zinco e potencial fitorremediador de mudas de espécies arbóreas / Tolerance to the heavy metals lend and zinc and phytoremediation potential of seedlings of tree species

Souza, Sarah Caroline Ribeiro, 1986-, Andrade, Sara Adrián López de, 1971- 15 August 2018 (has links)
Orientadores: Marlene Aparecida Schiavinato, Sara Adrian Lopez de Andrade / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T21:26:06Z (GMT). No. of bitstreams: 1 Souza_SarahCarolineRibeiro_M.pdf: 990180 bytes, checksum: a52442f68f3a27dfa82cded6425db23c (MD5) Previous issue date: 2010 / Resumo: A contaminação do solo por metais pesados (MPs), causada por processos naturais ou atividade humana, é um dos mais graves problemas ambientais devido à persistência e alto poder de toxicidade dos MPs. Em ambientes contaminados por MPs, as plantas podem apresentar uma série de distúrbios fisiológicos e nutricionais. No entanto, algumas espécies de plantas são tolerantes aos MPs e essa tolerância tem sido selecionada durante a evolução, e envolve diversos mecanismos. A associação com fungos micorrízicos arbusculares (FMAs) pode reduzir os efeitos negativos do estresse induzido por altas concentrações de metais sobre a planta hospedeira. Considerando a existência de plantas tolerantes, a fitorremediação, especialmente com espécies arbóreas, aparece como uma estratégia eficiente para a reabilitação de áreas contaminadas com MPs, uma vez que essas espécies imobilizam os metais absorvidos por mais tempo em seus tecidos. Assim, este estudo teve como objetivos: avaliar a tolerância, o acúmulo e a distribuição dos MPs, Pb e Zn, em três espécies de leguminosas nas diferentes partes das plantas; avaliar a influência destes metais na colonização micorrízica e na fixação biológica de nitrogênio e avaliar o potencial fitorremediador de cada espécie. Foram realizados dois experimentos, um com Pb e outro com Zn, com delineamento experimental totalmente casualizado e em esquema fatorial 3 x 4. Os tratamentos consistiram em três espécies de leguminosas arbóreas Mimosa caesalpiniaefolia (sansão-do-campo), Erythrina speciosa (eritrina-candelabro) e Schizolobium parahyba (guapuruvu) e quatro concentrações de metais, 0, 250, 500 e 1000 mg.dm-3 de Pb e 0, 200, 400 e 600 mg.dm-3 de Zn, adicionados ao solo na forma de acetato de chumbo e sulfato de zinco. Após aproximadamente 180 dias de cultivo as mudas foram coletadas. Determinaram-se altura, área foliar total, massa da matéria seca (MS) da parte aérea e raízes, número de nódulos e MS de nódulos das espécies que nodulam. Na espécie que não nodula, S. parahyba, foi feita a medição da raiz pivotante e o volume total de raízes. Foram feitas as determinações dos teores de Pb e Zn, dos nutrientes essenciais e calculado o índice de translocação (IT). Foram determinados o conteúdo de pigmentos fotossintéticos, a atividade da nitrogenase, aminoácidos livres, nitrato, amônia, peroxidação lipídica (MDA) e a taxa de colonização micorrízica. Os dados foram submetidos à análise de variância, análise de regressão e teste de Tukey. Verificou-se que altas concentrações de Zn adicionadas ao solo afetam mais significativamente o desenvolvimento de mudas de espécies arbóreas quando comparadas às concentrações de Pb utilizadas. Todas as espécies apresentam maiores concentrações de Zn e Pb nas raízes que agem como uma barreira à translocação dos MPs, considerado um mecanismo de fitoestabilização. O fato de serem espécies de leguminosas arbóreas de crescimento rápido, de fácil propagação, sistema radicular extenso e aliado ao fato de conseguirem absorver e concentrar os metais pesados Pb e Zn em suas raízes, sugere que estas espécies arbóreas analisadas podem ser potencias plantas fitorremediadoras de solos moderadamente contaminados, sendo que, para o Pb a espécie mais tolerante seria M. caesalpiniaefolia e para o Zn, a E. speciosa. / Abstract: Soil contamination by heavy metals (HM), caused by natural processes or human activity, is one of the most serious environmental problems due to their persistence and high toxicity potential. In HM contaminated environments, plants may present a series of physiological and nutritional disorders. However, some plant species are tolerant to HM and this tolerance has been selected during evolution. The mechanisms involved in plant tolerance to HM excess are diverse and varied. The association with arbuscular mycorrhizal fungi (AMF) can reduce the negative effects of stress induced by high concentrations of metals to the host plant. Considering the existence of tolerant plants, phytoremediation appears as na efficient strategy for the rehabilitation of areas contaminated with HM, especially using tree species, since these species immobilize absorbed metals for greater time periods in their tissues. Thus, this study aimed to evaluate the tolerance, accumulation and distribution of Pb and Zn in three species of leguminous trees, and further, to evaluate the influence of these metals in mycorrhizal colonization and nitrogen fixation and evaluate the phytoremediator potential of each of the studied species. For this purpose, two experiments were conducted, one with Pb and another with Zn, with a completely randomized experimental design in a factorial 3 x 4 scheme. The treatments consisted of three species of tree legumes Mimosa caesalpiniaefolia (sansão-do-campo), Erythrina speciosa (eritrinacandelabro) and Schizolobium parahyba (guapuruvu) and four concentrations of metal, 0, 250, 500 and 1000 mg.dm-3 Pb and 0, 200, 400 and 600 mg.dm-3 Zn added to soil in the form of lead acetate and zinc sulfate. Approximately 180 days after sowing, the seedlings were collected. We determined the height and total leaf area, the dry matter (DM) of shoots and roots, nodule number and nodule DM of nodulating species. In species that do not nodulate, S. parahyba, measurements were made of the tap root and root volume. Determinations were made of the levels of Pb and Zn as well as essential nutrients and the rate of translocation (IT) was calculated. The content of photosynthetic pigments was determined as well as photosynthesis, nitrogenase activity, amino acids, nitrate, ammonia and lipid peroxidation (MDA) and the rate of colonization was estimated. The data were subjected to analysis of variance, regression analysis and the Tukey test (5% significance). It was found that the higher concentrations of Zn added to soil affected the development of seedlings of the tree species studied more significantly than those of Pb. All species had higher Zn and Pb concentrations in their root, indicating this organ acts as a barrier for metal translocation to the shoots in these plants, considered a phytostabilization mechanism. The fact that these species are fast growing, easily propagated and have a extensive root system that can absorb and concentrate Pb and Zn, suggests that they have potential for use in phytoremediation of contaminated soils. / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal
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Nature, périodicité des cernes et dendroclimatologie sur Gmelina arborea au Mali

Kone, Bather 05 April 2024 (has links)
L'objectif que nous visions dans notre recherche était l'étude de la structure anatomique du Gmelina arborea, ainsi que la nature et la périodicité des cernes en première instance, et ensuite l'étude de l'influence de l'âge, des conditions climatiques et des traitements sur la largeur des cernes au Mali. Pour cela, nous avons pris un total de 37 arbres venant de sites différents (Monts Mandingues, Faya, Farako) et nous avons prélevé des rondelles sur ces arbres. Ensuite, par des examens macroscopiques et microscopiques, nous avons essayé un repérage et un comptage des cernes. Nous avons trouvé que le Gmelina arborea forme des cernes annuels, entre autre des particularités présentant des difficultés d'interprétation. Parmi celles-ci, les cernes des premières années que nous avons appelés "pseudo-cernes", les faux-cernes, les cernes accidentels ou traumatiques, les cernes incomplets, les cernes étroits, et rarement, les veines colorées. Les cernes annuels ne présentent pas la structure de bois initial et bois final à une observation macroscopique, bien qu'au point de vue microscopique, on puisse observer parfois des différences d'épaisseur des parois des fibres. Les cernes annuels sont beaucoup mieux visibles dans les Gemlina des Monts Mandingues et de la Faya que ceux de Farako qui présentent des cernes beaucoup plus onduleux dans les dernières années qui ont précédé l'abattage des arbres. En général, les cernes ont une largeur très variable en suivant la circonférence de l'arbre. Nous avons trouvé que c'est la courbe polynomiale de la forme: y = A₀ + A₁/ x +A₂ x (où x est l'âge de l'arbre, y la largeur de cerne correspondante, A₀, A₁ et A₂ des coefficients) qui convient le mieux comme courbe de fonction de croissance biologique du Gmelina au Mali. Le site a une influence sur la largeur des cernes, et nous avons constaté que la croissance était meilleure aux Monts Mandingues et à la Faya qu'à Farako; alors que la pluviométrie de la région de Sikasso (où se trouve la plantation de Farako) est nettement supérieure à celle de la région de Bamako. On a essayé d'interpréter ce phénomène par la dégradation des sols, la concurrence de la végétation arbustive, la vigueur de la strate graminéenne et le moindre entretien des plantations à Farako. Nous avons essayé d'étudier l'influence des différents facteurs climatiques sur la largeur des cernes; ceci nous a donné 36% de coïncidence avec la pluviométrie et 18% avec l'humidité relative aux Monts Mandingues, 55% avec la pluviométrie de la Faya, alors qu'à Farako, nous avons eu 57% pour la pluviométrie et 29% pour l'humidité relative. Il convient cependant de souligner ici l'éloignement des stations de relevés météorologiques qui doit avoir son influence. Nous pensions trouver des largeurs plus faibles pour les années correspondantes de la période de sécheresse du Sahel; tel n'a pas été le cas, ce qui pourrait agréer davantage l'hypothèse qui veut que le rythme de croissance soit commandé plus par des causes génétiques. Le traitement par éclaircie a également une influence sur la largeur des cernes annuels. Dans le cas des Monts Mandingues, il apparaît que le taux optimum est de 50% puisqu'il donne des largeurs de cernes supérieures à celles du taux de 75%. De plus, il semble que l'effet de l'éclaircie sur la largeur des cernes ne dura pas plus de 7 années. Compte tenu des valeurs que nous avons obtenues et de l'importance de l'estimation de la largeur moyenne des cernes, nous pensons qu'il serait d'un grand intérêt de tenir compte de l'orientation dans la mesure des cernes. Ainsi, on pourrait mesurer des largeurs sur une orientation donnée et les utiliser pour les analyses.
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Atividade inseticida dos óleos essenciais de manjericão e candeeiro e seus componentes sobre Callosobruchus maculatus (Coleoptera: Bruchidae) / Insecticidal activity of essential oils of basil and lamp and its components on Callosobruchus maculatus (Coleoptera: Bruchidae)

Moura, Eridiane da Silva 17 June 2015 (has links)
Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-02-15T13:55:21Z No. of bitstreams: 1 texto completo.pdf: 1142937 bytes, checksum: 0984fe5cce7d693509543f408c6416db (MD5) / Made available in DSpace on 2016-02-15T13:55:21Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1142937 bytes, checksum: 0984fe5cce7d693509543f408c6416db (MD5) Previous issue date: 2015-06-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O feijão-caupi (V. unguiculata) destaca-se como alimento para a população e alternativa de renda principalmente no Nordeste, com 60% da produção do gênero Vigna. O cultivo deste feijão está sujeito a perdas pós-colheita, devido a pragas no armazenamento, incluindo Callosobruchus maculatus (Coleoptera: Bruchidae). Inseticidas sintéticos são eficazes contra essa praga, mas seu uso excessivo pode comprometer a qualidade dos alimentos e ocasionar resistência nos insetos. Em razão deste problema, métodos alternativos para o controle de insetos em grãos armazenados, como inseticidas de origem vegetal, tem sido pesquisados. O objetivo deste trabalho foi avaliar a inibição da oviposição, taxa instantânea de crescimento populacional (ri), taxa de desenvolvimento de C. maculatus e a perda de massa de grãos de feijão-caupi após aplicação dos óleo essenciais de Ocimum basilicum (manjericão) e Vanillosmopsis arborea (candeeiro) e seus principais componentes (linalol, estragol e - bisabolol). As unidades experimentais foram constituídas por frascos de 0,8 L tratados com -1 -1 -1 -1 de ar de ar; -1 -1 de ar -1 de ar -1 de ar -1 de ar dos óleos essenciais de manjericão, linalol e estragol -1 de ar -1 de ar -1 de ar de ar -1 de ar -1 de ar de ar de ar; -1 -bisabolol. O óleo essencial de manjericão e os componentes linalol e estragol foram diluídos em etanol e o óleo essencial de candeeiro e o componente -bisabolol em h ou componente foi aplicado por disco de papel filtro com uma microsseringa. O disco de papel foi colocado em placa de Petri coberta com organza em um frasco com 20 insetos adultos sexados ou não, para a avaliação da toxicidade para machos e fêmeas de C. maculatus com 1 a 2 dias de idade. Cada tratamento teve quatro repetições com os insetos expostos ao óleo por fumigação durante 48 h. A taxa de desenvolvimento de C. maculatus foi avaliada com procedimento semelhante, mas a contagem dos adultos foi realizada diariamente após a emergência do primeiro. A oviposição desse inseto foi avaliada nas concentrações letais (CL50, CL25, CL10 e CL1) com 10 casais expostos as mesmas por fumigação durante 48 h (4 repetições por tratamento) e o número de ovos contabilizado por repetição. As CL50 e CL95 do estragol L-1 de ar, -1 -bisabolol foram de -1 -1 de ar -1 de ar -1 respectivamente. As CL50 e CL95 foram de -1 -1 de ar de ar de ar -1 de ar -1 de ar, de ar para de ar para linalol. O aumento das concentrações dos óleos essenciais reduziu a ri, a taxa de desenvolvimento, oviposição e o número de ovos. A perda de massa do feijão tratado com óleo essencial de manjericão foi de 8,2% e a do controle de 14,9%. O feijão tratado com o óleo essencial de candeeiro mostrou perda de 8,4% comparado ao controle, de 15%. Linalol e estragol foram letais a C. maculatus em menores concentrações que os óleos essenciais de manjericão e candeeiro e mostraram maiores inclinações das curvas de mortalidade, o que pode ser explicado pela sua ação de inibição mista à enzima acetilcolinesterase (AChE) ao se ligar à enzima livre e ao complexo enzima- -bisabolol foi mais letal em menores concentrações (CL50 e CL95) para C. maculatus que o óleo essencial de candeeiro, o que pode se explica pelo seu mecanismo de ação que está relacionado com a ativação dos canais K+ATP. Os óleos essenciais de manjericão e candeeiro -bisabolol, possuem efeito inseticida fumigante sobre adultos de C. maculatus e representam uma alternativa ao uso de inseticidas sintéticos. / The cowpea (V. unguiculata) stands out as food for the population and alternative income mainly in the Northeast, with 60% of production of Vigna genre. The cultivation of beans is subjected to postharvest losses due to storage pests, including Callosobruchus maculatus (Coleoptera: Bruchidae). Synthetic insecticides are effective against this pest, but their excessive use may compromise the quality of food and cause resistance in insects. By reason of this problem, alternative methods for the control of insects in stored grains such as vegetable insecticides, have been researched. The objective of this study was to evaluate the inhibition of oviposition, instantaneous rate of population growth (laughs), C. maculatus development rate and the mass loss of cowpea beans after application of the essential oil of Ocimum basilicum (basil) and Vanillosmopsis arborea (lamp) and its main components -bisabolol). The experimental units consisted of 0.8 L bottles treated with 1,2 L L-1 air; 1,6 L L-1 air; 2 L L-1 air; 2,4 L L-1 air; 2,8 L L-1 air; 3,2 L L-1 air and 3,6 L L-1 air to basil essential oil, linalool and estragole and ,2 L L-1 air; 1,6 L L-1 air; 2 L L-1 air, 2,4 L L-1 air; 2,8 L L-1 air; 5,6 L L-1 air; 8,4 L L-1 air e 11,2 L L-1 air for the essential oil lamp and the -bisabolol. The essential oil of basil and linalool and estragole were dil -bisabolol in hexane. A total of 25 L of each solution or oil component was applied by the filter paper disc with a microsyringe. The paper disc was placed in a covered petri dish with organza a vial with the components sexed and 20 adult insects or not for the evaluation of toxicity to C. maculatus males and females with 1 to 2 days old. Each treatment was replicated four times with the oil insects exposed for 48 h. The instantaneous rate of increase (ri) in the presence of essential oils was determined with the lethal concentrations (LC50, LC25, LC10, LC1, LC0,5 e LC0,25) of bioassays of toxicity. Bottles with 100 g of bean and 20 adult insects, non-sexed aged 1-2 days, and four replications were used for LC. After 45 days, the adult offspring was recorded. A similar procedure was done to assess the development rate, but the count was performed daily after the emergence of the first adult. The paper disc was placed in a covered Petri dish with organza and added at the bottom of the flasks then received 20 adult insects or unsexed sexed in the case of the evaluation of toxicity for males and females aged 1 to 2 days. Each treatment consisted of 4 replications, and the insects were exposed to oil for fumigation for 48 h. The instantaneous rate of increase (laughs) insects in the presence of essential oils was determined using the lethal. Oviposition was evaluated in lethal concentrations (LC 50, LC25, LC10 and LC1) 10 couples with the same exposed for fumigation for 48 hours (four replications per treatment), and counted the number of eggs per replicate. The LC 50 and LC95 were 1.79 L L-1 air and 4.36 L L-1 air to 1.68 L L-1 air and basil oil and 3.35 L L-1 air to linalool respectively. The LC50 and LC95 showed estragole 1.51 L L-1 air and 2.87 L L-1 air, essential oil lamp showed 5.23 L L-1 air for the LC50 and LC95 was 12.97 L L-1 air. The -bisabolol 2.47 L L-1 air and 8.82 L L-1 air to LC50 and LC95, respectively. Increasing concentrations of essential oils decreased the laughs, the rate of development and oviposition. The number of eggs decreased with increasing concentrations. The mass loss of the treated beans with basil essential oil was 8.2% and in control of 14.9%. The essential oil lamp showed loss of 8.4% compared to the control of 15%. Linalool and estragole were lethal to C. maculatus at concentrations less than the essential oils of basil and lamp and showed higher slopes of the mortality curves, which can be explained by its action mixed inhibiting the enzyme acetylcholinesterase (AChE) to connect to free and enzyme-substrate complex -bisabolol was deadliest in lower concentrations (LC50 and LC95) for C. maculatus that the essential oil lamp, which can be explained by their mechanism of action that is related to the activation of K+ ATP channels. The essential oil of basil and lamp and its -bisabolol possess fumigant insecticidal effect on adults C. maculatus and represent an alternative to the use of synthetic insecticides.

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