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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.
101

Influência da temperatura e período de molhamento no desenvolvimento da antracnose e nas características físico-químicas da banana

PESSOA, Wagner Rogério Leocádio Soares 28 February 2005 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-23T15:49:15Z No. of bitstreams: 1 Wagner Rogerio Leocadio Soares Pessoa.pdf: 1202325 bytes, checksum: 24359deb95d67f77dc4011b48213d142 (MD5) / Made available in DSpace on 2017-03-23T15:49:15Z (GMT). No. of bitstreams: 1 Wagner Rogerio Leocadio Soares Pessoa.pdf: 1202325 bytes, checksum: 24359deb95d67f77dc4011b48213d142 (MD5) Previous issue date: 2005-02-28 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The banana is the second largest fruit more consumed in the world, being the fresh fruit that detain the largest market. Brazil blunts as second largest producer of the fruit. In Brazil the varieties Silver and Pacovan approximately 60 % of the cultivate area. However, several phytopathological factors such as fungi and bacteria can cause the banana crop losses that could reach up to 40 %. Among these factors, anthracnose caused by Colletotrichum musae, deserve special attention in harming the commercialization and the consumption in natura. Because of the importance of this disease in banana and the lack of information on the subject, this work had two objectives: 1) study the influence of inoculation methods, different temperatures associates to different wetness period on the development of the disease; 2) verify alterations physicalchemistry happened in the banana fruits. The fruits were inoculated with 17 isolated of C. musae in two ways using PDA disk containing structures of the pathogen and suspension of conidia 4x 106 conidia / mL. The banana fruits were inoculated with the pathogen in the presence or not of artificial wounds. All C. musae isolates were pathogenic independently of the inoculation method used. Lesions could be observed in artificially wounded fruits independently of the inoculation method used (disk and suspension). In order to access the influence of temperature and wetness period, the isolates MAG2, SFV1 and FSA of C. musae were used isolated. These isolates were chosen because they show a wide rage of aggressiveness in the pathogenicity test. The bananas fruits were inoculated and incubated in the temperatures of 10, 15, 20, 25 and 30 oC with periods of wetness of 0, 12, 24 and 36 h, during five days. Temperatures of 20, 25 and 30 oC and with increasing wetness periods favored the development of lesions. Largest lesions wereobserved in the temperatures around 25 to 30 oC and 36 h of wetness period. Several physicalchemical alterations could be observed in the fruits during thexperiment: 1) there was an increase in the banana fruit humidity as the temperature and the wetness period increased, 2) They reach its highest pH value at 30 oC independently of the wetness period, 3) The largest ATT for the isolates SFV and MAG occurred at the same temperature of 25 oC, with wetness period of 12 and 24 h, respectively. The largest ATT value for the isolate FSA occurred at the temperature of 15 oC associated to the wetness period of 36 h, 4) Maximum SST occurred at temperature around 20 oC independent of the wetness period, 5) The largest potassium levels was reach at the temperature of 10 oC with wetness period of 24 h for SVF and MAG and without wetness period in FSA, 6) The total sugars content increased with the elevation of the temperature, decrease as the temperature approached of 30 oC, independent of the wetness period and the isolated of C. musae used. / A banana é a segunda fruta mais consumida no mundo, sendo (a fruta fresca neste contexto detentora de maior mercado no mundo) o Brasil segundo maior produtor, utilizando as variedades Prata e Pacovan em aproximadamente 60% de sua área cultivada. Entretanto, diversos fatores podem ocasionar perdas na produção, podendo chegar à ordem de 30 a 40%. Entre estes fatores encontram-se fungos e bactérias, merecendo destaque especial na pós-colheita a antracnose, causada por Colletotrichum musae, prejudicando a comercialização e o consumo in natura. Diante da importância desta doença na banana e a carência de informações sobre o assunto, este trabalho teve por objetivos, estudar a influência de métodos de inoculação, diferentes temperaturas associadas a distintos períodos de molhamento sobre o desenvolvimento da doença, e sua influência nas características físicoquímica. Avaliaram-se 17 isolados de C. musae, utilizando-se dois tipos de inóculo: disco de meio BDA contendo estruturas do patógeno e suspensão de conídios 4x106 conídios/mL, em duas formas de inoculação: com e sem ferimentos. Todos os isolados de C. musae mostraram-se patogênicos independente do tipo de inóculo utilizado. As lesões ocorreram nas frutas com ferimento, independente do tipo de inóculo (disco e suspensão). Para o estudo da influência da temperatura e período de molhamento, utilizaram-se três isolados do patógeno MAG2, SFV1 e FSA, por mostraram-se mais agressivo, intermediário e menos agressivo, respectivamente, no teste de patogenicidade. Asfrutas foram inoculadas e incubadas nas temperaturas de 10, 15, 20, 25 e 30oC e períodos de molhamento de 0, 12, 24 e 36 h, por cinco dias. As temperaturas em torno de 20, 25 e 30oC independente do período de molhamento favoreceram um maior desenvolvimento de lesões. As alterações físico-química mostraram que houve um aumento de umidade da fruta à medida que a temperatura e o período de molhamento aumentavam. Valores mais elevados de pH ocorreram em torno da temperatura de 30oC, independente do período de molhamento. Em relação a Acidez Titulável Total (ATT) para o isolado SFV1 e MAG2 ocorreu na temperatura ao redor de 25oC, com período de molhamento de 12 e 24 h, respectivamente, e para o isolado FSA ocorreu ao redor da temperatura de 15oC associado ao período de molhamento de 36 h. O teor de Sólidos Solúveis Totais (SST) ficou em volta de 20oC independente do período de molhamento. A temperatura ao redor de 10oC favoreceu a elevação no nível de potássio das frutas, associado ao período de molhamento de 24 h, em frutas inoculadas com os isolados SVF1 e MAG2, e 0 hora quando utilizou-se o isolado FSA. Os teores de açúcares totais aumentaram com a elevação da temperatura, declinando à medida que esta se aproximava de 30oC, independente do período de molhamento e isolados de C. musae.
102

Development of an "A" genome-specific sequence characterised amplified region (SCAR) marker in Musa L. (bananas and plantains)

Mabonga, Lloyd 09 1900 (has links)
M. Tech. (Department of Biosciences, Faculty of Applied and Computer Sciences) Vaal University of Technology / Most cultivated bananas and plantains (Musa spp. sect. Eumusa), originated from two wild diploid species, Musa acuminata Colla (AA) and Musa balbisiana Colla (BB), which contributed the A and B genomes, respectively. The two genomes confer different traits to a banana plant. Intra- and interspecific hybridization between the wild diploid species, somatic mutations and selection over many thousands of years has given rise to considerable genetic variability in cultivated bananas. Bananas are classified according to its genome composition and a number of morphological traits are used to identify the genomes of a plant. Morphological classification can be misleading since the morphology of plants can be affected by environmental factors. Molecular techniques to identify the genomes of banana have many advantages. The objective of this study was to develop a SCAR (sequence characterized amplified region) marker from a previously reported A genome-specific RAPD fragment that distinguish the A genome of banana from the B genome. This fragment designated OPA17600 was cloned, sequenced and used to design longer 20-mer SCAR primers. Verification of the SCAR primers for its fidelity to the A genome was carried out on a sample of 22 homo-and heterogenomic accessions representing landraces and hybrids of different ploidy and genome combinations. Out of six primers sets that were tested one set (SC3) produced a unique 600 bp in all the A genome containing banana accessions. However, these primers also amplified an 800 bp fragment in all the BB genotypes and some accessions containing the A and B genomes. While previous reports suggested that there was considerable differentiation between the A and B genomes, recent evidence points to the contrary. The presence of the A genome fragment in the B genome genotypes and accessions may be due to recombination between the two genomes, translocations and substitutions. The study concluded that the 600-bp SCAR sequence is conserved across the A genome in Musa and can be used to identify the A genome in banana classification and Musa breeding programmes.
103

Beatriz, musa de Dante Alighieri, com suas transfigurações na Vita Nova e incursões na Divina Comédia / Beatriz, Dante Alighieris muse, her transfigurations in The New Life and incursions in The Divine Comedy

Robin, Paula Monteleone 01 April 2011 (has links)
A presente pesquisa teve como objetivo o estudo da Vita Nova de Dante Alighieri, onde o Amor, as musas e outros personagens surgem da mitologia grega. Esse Amor pagão é cristianizado por Dante, que o transforma na figura de Deus. Beatriz passa a ser a Musa de Dante, que é chamada pelo poeta primeiro de gentilissima, depois donna angelo, santa, filósofa e teóloga. No Convívio, pode-se constatar a aproximação de sua deusa à sabedoria filosófica e teológica. Tudo isso se passa pela elaboração da poesia, bem como a Divina Comédia, que são, segundo o autor, alegorias. Foram feitas algumas incursões na Divina Comédia para confirmar tais configurações entrou-se em trechos do Purgatório e do Paraíso. / The purpose of this research was to study Dante Alighieri\'s Vita Nova, where Love, muses, and other characters emerge from the Greek mythology. This pagan love is christianized by Dante, who transforms it into the figure of God. Beatrice becomes Dante\'s muse, who is initially called by him as very gentle lady, then as donna angelo (woman-angel), saint, philosopher and theologian. In Convivio, an approach between his goddess and a philosophical and theological wisdom can be observed. Convivio, as well as The Divine Comedy, are written in poetry and are both, according to the author, allegories.
104

Les îles d'Abou Moussa, de la Petite Tumb et de la Grande Tumb : une souveraineté contestée entre la République islamique d'Iran et les Émirats arabes unis / The islands of Abu Musa, Lesser Tunb and Greater Tunb : a sovereignty dispute between the Islamic Republic of Iran and the United Arab Emirate

Razavi, Seyed Abdoljalil 15 October 2016 (has links)
Dans cette recherche, nous avons opté pour une méthode à la fois descriptive, analytique et documentaire, fondée sur la collecte de données : enquêtes, entretiens et ressources de bibliothèque.Les résultats montrent qu’un pays nouvellement créé a besoin, pour se développer, de s’appuyer sur un sentiment d'intégration et d'identité nationale. Il semble que ce soit la raison fondamentale de la revendication par les Emirats arabes unis de ces îles appartenant à l’Iran, seul pays non arabe du golfe Persique. A travers ces revendications, les Emirats arabes unis ont pour objectif la création d’un Etat-nation. / In this research, we opted for a method that is descriptive, analytical and documentary, based on the collection of data in the forms of surveys, interviews and library resources. The results show that a newly created country, for its development, needs to build on a sense of integration and national identity. It seems that this is the fundamental reason for the claim by the United Arab Emirates on these islands belonging to Iran, the only non-Arab country of the Persian Gulf. Through these claims, the United Arab Emirates aim to creat a nation -state.
105

Beatriz, musa de Dante Alighieri, com suas transfigurações na Vita Nova e incursões na Divina Comédia / Beatriz, Dante Alighieris muse, her transfigurations in The New Life and incursions in The Divine Comedy

Paula Monteleone Robin 01 April 2011 (has links)
A presente pesquisa teve como objetivo o estudo da Vita Nova de Dante Alighieri, onde o Amor, as musas e outros personagens surgem da mitologia grega. Esse Amor pagão é cristianizado por Dante, que o transforma na figura de Deus. Beatriz passa a ser a Musa de Dante, que é chamada pelo poeta primeiro de gentilissima, depois donna angelo, santa, filósofa e teóloga. No Convívio, pode-se constatar a aproximação de sua deusa à sabedoria filosófica e teológica. Tudo isso se passa pela elaboração da poesia, bem como a Divina Comédia, que são, segundo o autor, alegorias. Foram feitas algumas incursões na Divina Comédia para confirmar tais configurações entrou-se em trechos do Purgatório e do Paraíso. / The purpose of this research was to study Dante Alighieri\'s Vita Nova, where Love, muses, and other characters emerge from the Greek mythology. This pagan love is christianized by Dante, who transforms it into the figure of God. Beatrice becomes Dante\'s muse, who is initially called by him as very gentle lady, then as donna angelo (woman-angel), saint, philosopher and theologian. In Convivio, an approach between his goddess and a philosophical and theological wisdom can be observed. Convivio, as well as The Divine Comedy, are written in poetry and are both, according to the author, allegories.
106

Caracterização morfológica e molecular de cultivares de bananeira / Morphological and molecular characterization of banana cultivars

JESUS, Onildo Nunes de 20 February 2006 (has links)
Submitted by (ana.araujo@ufrpe.br) on 2017-02-21T13:28:55Z No. of bitstreams: 1 Onildo Nunes de Jesus.pdf: 2414715 bytes, checksum: 214b16bf3a641fd0b947a2db75756cec (MD5) / Made available in DSpace on 2017-02-21T13:28:55Z (GMT). No. of bitstreams: 1 Onildo Nunes de Jesus.pdf: 2414715 bytes, checksum: 214b16bf3a641fd0b947a2db75756cec (MD5) Previous issue date: 2006-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Banana genetic breeding at Embrapa Cassava and Tropical Fruits has carried out great efforts in trying to obtain banana cultivars resistant to most pests and diseases and with good agronomic characteristics, once most of the existing cultivars are tall in height and susceptible to most diseases. In this attempt, great financial and intellectual efforts are required for the obtainment of new hybrids that present desirable characteristics. With the creation of the Cultivar Protection Law, the right to protect a cultivar being released, with the emission of a Cultivar Certificate, was instituted. Therefore, the characterization of new genotypes becomes necessary in order to minimize the risk of unlawful acquirement of cultivars being released. The actual characterization being accepted, is the one based in morphological descriptors, even though the isoenzime pattern has also been used. The characterization of the genotypes with morphological and isoenzimatic descriptors, present some limitations, for they are influenced by the environment and therefore, the use of DNA descriptors acting directly in the plant genome presents another tool to overcome these problems. The objective of the present work was to use two types of descriptors: morphological and molecular (RAPD and SSR) in thediscrimination of banana cultivars being recommended by Embrapa Cassava and Tropical Fruits. The morphological descriptors were made up of 12 quantitative and sixty-one qualitative characteristics. For the molecular characterization, 48 RAPD primers and 34 microsatellite primers were used. The results concluded that the application of the qualitative and quantitative descriptors showed a broad genetic variability between the genotypes studied, but the Preciosa, Pacovan Ken and Garantida cultivars presented little perceptible differences, being perceptible only at DNA level. The descriptors based on microsatellites were superior to the others due to their repeatability and high discriminating power, enabling the definition of molecular patterns for some of the cultivars evaluated. With the selected primers in addition to the ones indicated, the creation of a molecular data bank for varietal identification takes its first steps. / O melhoramento genético de bananeira da Embrapa Mandioca e Fruticultura Tropical vêm conduzindo esforços na tentativa de obter cultivares de bananeira resistentes às principais pragas e doença com boas características agronômicas, uma vez que a maioria das cultivares existentes apresenta porte elevado, além de serem suscetíveis às principais doenças. Nessa tentativa, grandes esforços financeiros e intelectuais são requeridos para a obtenção de novos híbridos que apresentem características desejáveis. Com a criação da Lei de Proteção de Cultivares, foi instituído o direito a proteção da cultivar que é efetivada mediante a emissão de Certificado de Cultivar. Para tal, torna-se necessário caracterizar os novos genótipos, para minimizar os riscos da apropriação indevida dos mesmos e maximizar a eficiência dos programas de melhoramento e a utilização do germoplasma elite. A caracterização atualmente aceita é a baseada em descritores morfológicos, embora padrões de izoenzimas têm sido também usados. A caracterização dos genótipos com descritores morfológicos e izoenzimáticos, apresenta algumas limitações por ser influenciada pelo ambiente, portanto, a utilização de descritores de DNA atuando diretamente no genoma da planta, apresenta-se como solução para contornar estes problemas. O presente trabalho teve como objetivo utilizar dois tipos de descritores: morfológico e molecular (RAPD e SSR),na diferenciação de cultivares de bananeira recomendadas pela Embrapa Mandioca e Fruticultura Tropical. Os descritores morfológicos constituíram-se de 12 características quantitativas e 61 características qualitativas. Para a caracterização molecular, utilizou 48 primers de RAPD e 37 primers de microssatélites. Os resultados permitiram concluir que a aplicação dos descritores qualitativos e quantitativos mostrou uma ampla variabilidade genética entre os genótipos estudados, mas as cultivares Preciosa, Pacovan Ken e Garantida apresentaram pouca diferença, diferença esta perceptível somente em nível de DNA. Os descritores baseados em microssatélites foram superiores aos demais pela repetibilidade e alta capacidade discriminatória detectada, permitindo definir padrões moleculares para algumas cultivares avaliadas. Com os primers selecionados, somados aos já indicados, tem-se o inicio da criação de um banco de dados moleculares para a identificação varietal de bananeiras.
107

Influ?ncia de Planta??es de Banana na assembleia de morcegos (Chiroptera) e na dieta e dispers?o de sementes / Influence of banana plantations in bats (Chiroptera) assemblage, diet and seed dispersal.

Luz, J?lia Lins 29 February 2012 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-05T12:02:33Z No. of bitstreams: 1 2012 - Julia Lins Luz.pdf: 1276196 bytes, checksum: 90a4bf9cffa0df2d66d28e4e7c42b80b (MD5) / Made available in DSpace on 2017-04-05T12:02:33Z (GMT). No. of bitstreams: 1 2012 - Julia Lins Luz.pdf: 1276196 bytes, checksum: 90a4bf9cffa0df2d66d28e4e7c42b80b (MD5) Previous issue date: 2012-02-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Modification of the landscape for food production and other facilities for human consumption is the most common and severe threat to global biodiversity. The aims of this study were to analyze how banana plantations affect bats assemblages, to check whether the planting of bananas causes a decrease in the dispersion of seeds, to verify if the abundance of nutritional resources have some influence on bat abundance and richness in areas of banana plantation, to verify if bats move between plantations and forest fragments or if they show site fidelity to the areas. A total of 12 banana plantations in Rio de Janeiro State were sampled. Each month, from November 2008 to October 2010, two capture nights were conducted, being one night in a banana plantation area and another in an adjacent forest fragment. Bats were sampled with mist nets, totaling 142,560 m2.h of sampling effort. Bats were identified, marked, remained in cloth bags to obtain fecal samples, and released after it. The seeds obtained in fecal samples were counted and classified. The availability of food resources in banana plantation areas was estimated in five 100 m2 plots, where the number of banana trees, flowers and fruits was counted. A total of 2,369 captures and recaptures of bats of 27 species were recorded. In banana plantations 22 species were recorded (four of which were exclusive to such habitat), and in fragments 23 (with five exclusive). The capture frequency was higher in plantations than in fragments. Richness, diversity and evenness were similar between habitats. Artibeus lituratus, Carollia perspicillata, Glossophaga soricina and Phyllostomus hastatus were more abundant in the banana plantations. The abundance of frugivores, nectarivores and omnivores was higher in plantation areas while insectivores were more abundant in forest areas. The estimated richness for each environment suggests that forest fragments are richer than the banana plantations. A non-metric multidimensional scaling (NMDS) indicated separation between banana plantations and forest fragments based on species abundance, using Braycurtis similarity. We analyzed 1,127 fecal samples from 20 species that had 33 morphotypes of seeds of 12 plant families. There was presence of banana pulp in fecal samples from 10 species. The richness and abundance of seeds dispersed in the two environments did not differ, however the abundance of seeds per fecal sample was lower in banana plantations. The abundance of Sturnira lilium was correlated negatively with the abundance of banana and fruits. The abundance of G. soricina, A. lituratus, nectarivorous and frugivorous bats showed positive relationship with the abundance of food resource. We obtained 102 recaptures of 99 individuals of 10 species. The most recaptured species were C. perspicillata, A. lituratus and P. hastatus. Twenty-eight individuals moved between environments, 68 remained in the same environment of the capture. In all analyzed cases, the proportion of individuals recaptured in the same location of capture was higher than the recapture proportion in different environments. These results reinforce the potential of bats as regenerators in habitats modified by humans, since banana plantations maintain a diverse assemblage. The ability of bats to disperse pioneer plants species and the use of different environments assure that nature services of forest regeneration are continued / A modifica??o da paisagem para a produ??o de alimentos e outras comodidades para consumo humano representa a mais severa e comum amea?a ? biodiversidade global. Os objetivos deste trabalho foram analisar como o plantio de bananas afeta a comunidade de morcegos, analisar se o plantio de bananas diminui a dispers?o de sementes, verificar se a abund?ncia de recurso alimentar influencia a abund?ncia e a riqueza de morcegos em ?reas de planta??o de banana, verificar se os morcegos se deslocam entre ?reas de planta??es e fragmentos florestais e se mant?m fidelidade ? ?rea de captura. Foram selecionadas 12 ?reas de planta??o do estado do Rio de Janeiro. Mensalmente, entre novembro de 2008 e outubro de 2010, foram realizadas duas noites de coleta, sendo uma em ?rea de planta??o de banana e outra em um fragmento florestal adjacente. As coletas foram realizadas com redes de neblina, totalizando 142.560 m2.h de esfor?o amostral. Os morcegos foram identificados, permaneceram em sacos de pano para obten??o de amostras fecais, e soltos ap?s receberem marca??o. No laborat?rio, as sementes foram classificadas em morfotipos e contadas. A disponibilidade de recurso alimentar nas ?reas de planta??o de banana foi estimada atrav?s de cinco plots de 100 m2 , nos quais era contabilizado o n?mero de bananeiras, infrutesc?ncias e infloresc?ncias de banana. Um total de 2.369 capturas e recapturas de 27 esp?cies foi registrado. Nos bananais, foram capturadas 22 esp?cies, sendo quatro exclusivas; nos fragmentos, 23, sendo cinco exclusivas. A frequ?ncia de captura nos bananais foi maior do que nos fragmentos. A riqueza, a diversidade e a equitabilidade mostraram-se similares. As esp?cies significativamente mais abundantes nos bananais foram Artibeus lituratus, Carollia perspicillata, Glossophaga soricina e Phyllostomus hastatus. A abund?ncia de frug?voros, nectar?voros e on?voros foi maior em ?reas de plantio, enquanto a de inset?voros foi maior em ?reas de floresta. A riqueza estimada para cada ambiente sugere que os fragmentos florestais s?o mais ricos do que as ?reas de plantio. Uma an?lise de escalonamento multidimensional (NMDS) indicou separa??o entre os bananais e os fragmentos florestais baseado no n?mero de capturas por esp?cie, atrav?s da dist?ncia Bray-curtis. Foram analisadas 1.127 amostras fecais de 20 esp?cies, que apresentaram sementes de 33 morfotipos de 12 fam?lias de plantas. Foi poss?vel verificar a presen?a de polpa de banana em amostras fecais de 10 esp?cies. A riqueza e abund?ncia de sementes dispersadas nos dois ambientes n?o diferiram. No entanto, a abund?ncia de sementes por amostra fecal foi menor em ?reas de planta??o de banana. A abund?ncia de Sturnira lilium foi inversamente proporcional ? abund?ncia de bananeiras e infrutesc?ncias de banana. A abund?ncia de G. soricina, A. lituratus, morcegos nectar?voros e frug?voros foi diretamente proporcional ? abund?ncia de recurso alimentar. Foram obtidas 102 recapturas de 99 morcegos de 10 esp?cies. As esp?cies mais recapturadas foram C. perspicillata, A. lituratus e P. hastatus. Vinte e oito indiv?duos transitaram entre os ambientes, 68 permaneceram no mesmo ambiente da captura e tr?s foram recapturados duas vezes, uma em cada ambiente. Em todos os casos analisados, a propor??o de indiv?duos recapturados no mesmo local da captura foi maior do que a propor??o de indiv?duos recapturados em ambientes diferentes. Em ?reas de planta??o de banana, a ordem Chiroptera foi capaz de manter uma comunidade diversa, a capacidade de dispers?o de esp?cies pioneiras de plantas e a capacidade de deslocamento. Esses resultados refor?am o potencial dos morcegos como regeneradores de habitats modificados pelo homem.
108

Conception assistée par modèle de systèmes de culture durables : Application aux systèmes bananiers de Guadeloupe

TIXIER, Philippe 14 December 2004 (has links) (PDF)
Aujourd'hui, la culture bananière aux Antilles est confrontée à d'importants problèmes agronomiques (rendements faibles à cause du développement important de pathogènes), environnementaux (transport de pesticides et de sol vers les eaux de surface, dans un contexte écologique insulaire fragile) et économiques (variation du prix de vente des fruits et coût de la main d'œuvre élevé) susceptibles de remettre en cause la pérennité de la filière. Dans ce contexte, des systèmes de culture innovants répondant à un nouveau cahier des charges économique et environnemental doivent être mis au point. Plusieurs voies sont explorées qui, au delà d'un mode de conduite raisonné, visent à l'intégration de jachères, de rotations ou de plantes associées. <br /><br />L'évaluation et la conception de tels systèmes de culture innovants nécessitent l'utilisation d'outils de modélisation spécifiques qui rendent compte des caractéristiques particulières du système. Un modèle spécifique appelé SIMBA à été développé dans ce sens. SIMBA simule l'évolution de la structure du peuplement de bananiers au cours des cycles de culture, point clé qui conditionne l'ensemble de la dynamique du système. La composante parasitaire, qui influe sur la pérennité de la bananeraie et conditionne l'emploi des produits phytosanitaires est également prise en compte. Le parasitisme des nématodes phytoparasites est simulé, en interaction avec la croissance et la structure du peuplement, l'état du sol et l'emploi de nématicides. SIMBA simule également la croissance des bananiers et leur productivité, la structure du sol, la couverture du sol et le bilan hydrique. Des indicateurs qualitatifs et intégrateurs, conçus spécifiquement, permettent, couplés à ces modules biophysiques, l'évaluation au cours du temps de risques environnementaux comme le risque de pollution des eaux par les produits phytosanitaires et le risque d'érosion. Les pratiques culturales sont prises en compte à travers des règles de décision qu'il est ainsi possible d'évaluer. Le modèle SIMBA, en fournissant des sorties agronomiques, environnementales et économiques (marge brute), permet ainsi l'évaluation multicritère de systèmes de culture simulés selon plusieurs points de vue.<br /><br />SIMBA a ensuite été utilisé selon une méthode originale de prototypage en deux étapes (exploration globale puis optimisation spécifique). Les résultats obtenus ont permis d'identifier certains systèmes de culture qu'il conviendra de tester ‘au champ'. Cette approche systémique et fonctionnelle, qui a permis des avancées significatives au niveau de la modélisation des systèmes bananiers, constitue un outil performant pour la conception de systèmes de culture durables.
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Molecular cloning and characterisation of potential Fusarium resistance genes in banana (Musa acuminata ssp. Malaccensis)

Echeverria, Santy Peraza January 2007 (has links)
Banana is the most important fruit crop in the world but ironically one of the crops least studied. This fruit constitutes a major staple food for millions of people in developing countries and also it is considered the highest selling fruit in the world market making this crop a very important export commodity for the producing countries. At the present time, one of the most significant constraints of banana production that causes significant economical losses are fungal diseases. Among these, Panama disease, also known as Fusarium wilt has been the most catastrophic. Panama disease is caused by the soil-borne fungus Fusarium oxysporum formae specialis (f.sp) cubense (FOC), which infects susceptible bananas through the roots causing a lethal vascular wilt. To date, the race 4 of this pathogen represents the most serious threat to banana production worldwide since most of the commercial cultivars are highly susceptible to this pathogen. Introduction of FOC resistance into commercial cultivars by conventional breeding has been difficult because edible bananas are sterile polyploids without seeds. Genetic transformation of banana, which has already been established in various laboratories around the world has the potential to solve this problem by transferring a FOC race 4 resistance gene into susceptible banana cultivars (eg. Cavendish cultivars). However, a FOC resistant (R) gene has not been isolated. Genes that confer resistance to Fusarium oxysporum have been isolated from tomato and melon using a map-based positional cloning approach. The tomato I2 and melon Fom-2 genes belong to the non-Toll/interleukin like receptors (TIR) subclass of nucleotide-binding site and leucine-rich repeat (NBS-LRR) R genes. These genes confer resistance only to certain races of F. oxysporum in their corresponding plant families limiting their use in other plant families. The fact that these two Fusarium resistance genes share the same basic non-TIR-NBS-LRR structure suggests a similar Fusarium resistance mechanism is shared between the families Solanaceae and Cucurbitaceae. This observation opens the possibility to find similar Fusarium resistance genes in other plant families including the Musaceae. A remarkable discovery of a population of the wild banana Musa acuminata subspecies (ssp.) malaccensis segregating for FOC race 4 resistance was made by Dr. Ivan Buddenhagen (University of California, Davis) in Southeast Asia. Research carried out at Queensland Department of Primary Industries (Australia) using this plant material has demonstrated that a single dominant gene is involved in FOC race 4 resistance (Dr. Mike Smith, unpublished results). Tissue-culture plantlets of this FOC race 4 segregating population were kindly provided to the Plant Biotechnology Program (Queensland University of Technology) by Dr. Mike Smith to be used in our research. This population holds the potential to assist in the isolation of a FOC race 4 resistance gene and other potential Fusarium resistance genes. The overall aims of this research were to isolate and characterise resistance gene candidates of the NBS-type from M. acuminata ssp. malaccensis and to identify and characterise potential Fusarium resistance genes using a combination of bioinformatics and gene expression analysis. Chapter 4 describes the isolation by degenerate PCR of five different classes of NBS sequences from banana (Musa acuminata ssp malaccensis) designated as resistance gene candidates (RGCs). Deduced amino acid sequences of the RGCs revealed the typical motifs present in the majority of known plant NBS-LRR resistance genes. Structural and phylogenetic analyses showed that the banana RGCs are related to non-TIR subclass of NBS sequences. The copy number of each class was estimated by Southern hybridisation and each RGC was found to be in low copy number. The expression of the RGCs was assessed by RT-PCR in leaf and root tissues of plants resistant or susceptible to Fusarium oxysporum f. sp. cubense (FOC) race 4. Four classes showed a constitutive expression profile whereas no expression was detected for one class in either tissue. Interestingly, a transcriptional polymorphism was found for RGC2 whose expression correlated with resistance to FOC race 4 suggesting a possible role of this gene in resistance to this devastating FOC race. Moreover, RGC2 along with RGC5 showed significant sequence similarity to the Fusarium resistance gene I2 from tomato and were chosen for further characterisation. The NBS sequences isolated in this study represent a valuable source of information that could be used to assist the cloning of functional R genes in banana. Chapter 5 describes the isolation and characterisation of the full open reading frame (ORF) of RGC2 and RGC5 cDNAs. The ORFs of these two banana RGCs were predicted to encode proteins that showed the typical structure of non-TIR-NBS-LRR resistance proteins. Homology searches using the entire ORF of RGC2 and RGC5 revealed significant sequence similarity to the Fusarium resistance gene I2 from tomato. Interestingly, the phylogenetic analysis showed that RGC2 and RGC5 were grouped within the same phylogenetic clade, along with the Fusarium resistance genes l2 and Fom-2. These findings suggest that the banana RGC2 and RGC5 are potential resistance gene candidates that could be associated with Fusarium resistance. The case of RGC2 is more remarkable because its expression was correlated to FOC race 4 resistance (Chapter 4). As a first step to test whether RGC2 has a role in FOC race 4 resistance, different expression constructs were made with the ORF of this sequence. One of the constructs contains a RGC2 putative promoter region that was successfully cloned in this work. These constructs will be used to transform susceptible banana plants that can then be challenged with FOC race 4 to assess whether resistance has been acquired by genetic complementation. The results of this thesis provide interesting insights about the structure, expression and phylogeny of two potential Fusarium resistance genes in banana, and provide a rational starting point for their functional characterisation. The information generated in this thesis may lead to the identification of a Fusarium resistance gene in banana in further studies and may also assist the cloning of Fusarium resistance genes in other plant species.
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Efeito do líquido do pseudocaule da bananeira combinado com solução nutritiva na formação de mudas de bananeira. / Effect of fluid from the pseudostem of banana combined with nutrient solution in the formation of banana plantlets.

Severino, Daniely dos Santos Barboza January 2011 (has links)
SEVERINO, D. S. B. Efeito do líquido do pseudocaule da bananeira combinado com solução nutritiva na formação de mudas de bananeira. 2011. 86 f. Dissertação (Mestrado em Agronomia/Solos e Nutrição de Plantas) - Centro de Ciências Agrárias, Universidade Federal do Ceará, Fortaleza, 2011. / Submitted by Francisco Lacerda (lacerda@ufc.br) on 2014-08-19T19:10:14Z No. of bitstreams: 1 2011_dis_dsbseverino.pdf: 860276 bytes, checksum: a599ace8b6da04f4de4542ad726043db (MD5) / Approved for entry into archive by José Jairo Viana de Sousa(jairo@ufc.br) on 2014-08-27T17:35:22Z (GMT) No. of bitstreams: 1 2011_dis_dsbseverino.pdf: 860276 bytes, checksum: a599ace8b6da04f4de4542ad726043db (MD5) / Made available in DSpace on 2014-08-27T17:35:22Z (GMT). No. of bitstreams: 1 2011_dis_dsbseverino.pdf: 860276 bytes, checksum: a599ace8b6da04f4de4542ad726043db (MD5) Previous issue date: 2011 / The cultivation of banana trees generate lignoselulosic residue by cutting shoots and the plants after bunch collection. The pseudo-stem represents the largest portion of that residue and serves as a medium for the proliferation of pests in banana field. By industrial processing of that fibrous residue is also generated expressive volume of Net’s speudo-stem (LPCB). This study aimed to evaluate the effects LPCB combined with nutrient solution on physiological parameters, shot growth and nutrition of seedlings of the cultivar ‘Prata Anã’. Plantlets were grown on PVC columns of 20 cm diameter by 65 cm high filled with Ultisol from five layers (0-10, 10-20, 20-30, 30-40 and 40-60 cm) and subjected to five dosages of LPCB (0, 288, 576, 864 and 1152 mL, represented by volumetric combinations of water and LPCB (100:0, 75:25, 50:50, 25:75, 0:100, v:v), combined with two concentrations of Hoagland nutrient solution (one strength and half strength), using five replicates for each treatment. After 60 days of plant cultivation the stomata conductance, photosynthetic and chlorophyll contents in leaves were determined and, at the time of harvest, 68 days, were measured plant height and pseudo-stem diameter, counted leaves, determined fresh and dry weight of roots and aerial parts and analyzed N, K and Na contends in roots and aerial parts of banana plants. In layers of soil were evaluated microbiological and chemical characteristics. The results indicated that LPCB affects the dynamics of nutrients in the soil, favoring the accumulation of Na and K in a layer near the surface and reducing the pH in subsurface layers. The LPCB application rates increased microbial biomass and edaphic respiration. A higher dosage of that residue inhibits the plantlet growth and dry weight accumulation. The increasing of LPCB dosages promoted higher photosynthetic rate, but reduces stomata conductance, transpiration and chlorophyll content in leaves of banana plants. / No cultivo de bananeiras faz-se o desbaste de brotações e o corte de plantas que já frutificaram gerando resíduos lignocelulósicos. Os pseudocaules cortados formam a maior porção desse resíduo e servem como meio para proliferação de pragas na cultura. Na utilização industrial desse resíduo fibroso gera-se o Líquido do Pseudocaule da Bananeira (LPCB). Este estudo teve por objetivo avaliar efeitos do LPCB combinado com solução nutritiva nos parâmetros fisiológicos, no crescimento e na nutrição de mudas da cultivar Prata Anã. Mudas micropropagadas foram cultivadas em colunas de PVC de 20 cm de diâmetro por 65 cm de altura contendo cinco camadas de Argissolo (0-10, 10-20, 20-30, 30-40 e 40-60 cm) e submetidas a cinco dosagens do LPCB (0, 288, 576, 864 e 1152 mL), representados por concentrações volumétricas de água e o resíduo (100:0, 75:25, 50:50, 25:75, 0:100, v:v), combinadas com duas concentrações da solução nutritiva de Hoagland (uma força e meia força), utilizando-se cinco repetições em cada tratamento. Após 60 dias de cultivo determinou-se a taxa fotossintética, a condutância estomática e o teor de clorofila nas folhas e, na ocasião da colheita, aos 68 dias, obteve-se dados de altura e diâmetro do pseudocaule, número de folhas, peso fresco e seco das raízes e das partes aéreas e analisaram-se os teores de N, K e Na das raízes e das partes aéreas das bananeiras. Em camadas de solo avaliaram-se características microbiológicas e químicas. Os resultados indicaram que LPCB afeta a dinâmica de nutrientes no solo, favorecendo o acúmulo de Na e K numa camada mais próxima da superfície e reduzindo o pH do solo em camadas sub-superficiais. A aplicação do resíduo incrementou a biomassa microbiana e a respiração edáfica. Maiores doses do resíduo resultaram no menor crescimento e acúmulo de biomassa da parte aérea. A aplicação de doses crescentes do resíduo resultou no incremento da taxa fotossintética e na redução da condutância estomática, transpiração e teor de clorofila das folhas das bananeiras.

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