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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

Etude de la relation mycoparasitaire Trichoderma harzianum avec Fusarium solani chez l’Olivier ; caractérisations moléculaires et fonctionnelles des aquaporines chez Trichoderma harzianum / Study of mycoparasitic relationship between Trichoderma harzianum with Fusarium solani in Olive trees; Molecular and functional characterizations of aquaporins from Trichoderma harzianum

Ben Amira, Maroua 24 May 2018 (has links)
La lutte biologique par utilisation de micro-organismes a indéniablement un potentiel de développement considérable. Dans un contexte multidisciplinaire et fondamental de physio-phytopathologie moléculaire et répondant à d’éminents enjeux appliqués et attendus par les acteurs de la profession oléicole et les consommateurs, nous nous sommes projetés dans l’étude des propriétés intrinsèques d’un agent de biocontrôle fongique, Trichoderma harzianum (souche Ths97) contre l’agent de la fusariose Fusarium solani (souche Fso14), qui sévit sévèrement sur une culture pérenne majeure pour la Tunisie, l’oléiculture. Deux axes de recherche ont été menés. Dans le premier axe, nous avons démontré que Ths97 est un agent de biocontrôle efficace contre la virulence de F. solani Fso14. Cette capacité s’accompagne d’une accumulation des défenses chez le partenaire végétal, des accumulations qui sont d’autant plus fortes quand l’agent bénéfique est en présence du pathogène (événements de priming). De même, des tests in vitro montrent que Ths97développe des activités mycoparasites envers F. solani Fso14, en émettant des structures d’infection classiques tels des enroulements et accolements d’hyphes, des appressoria et des papilles. Quant au second axe d’étude, nous avons étudié la superfamille des perméases Major Intrinsic Proteins (MIP) dans le genre Trichoderma. Cette famille multigénique n’a jamais été étudiée chez un agent fongique hyperparasite. Sept membres MIP sont présents chez T. harzianum, et se classent en 3 sous-groupes, les AQP, les AQGP et les XIP. La modélisation des structures tridimensionnelles et les fonctions putatives de transport pour l’eau et quelques polyols ont été étudiées. Enfin, leurs patrons transcriptionnels ont été suivis chez Ths97 in planta en situation d’antagonisme et in vitro en situation de parasitisme vis-à-vis de Fso14, et montrent que 4 MIP sont exprimées et régulées différentiellement selon que Ths97 est au contact de Fso14 ou pas. Nos travaux ont donc mis en lumière que Ths97 doit être considéré comme un agent biofongicide et biostimulateur de défenses végétales, puis que les MIP seraient impliqués dans les relations trophiques que met en place T. harzianum avec son environnement. Ces données devraient intégrer le développement de procédés plus efficaces et/ou plus durables pour la protection des cultures d’oliviers en Tunisie ainsi qu’à travers le monde. / Biological disease control through the use of microorganisms has a great potential for future use in integrated pest management. In a multidisciplinary and fundamental context of molecular physio-phytopathology and to provide solutions for the actors in the olive profession and the consumers, we have been studying the activity of a fungal biocontrol agent, Trichoderma harzianum (strain Ths97) against the olive tree pathogen Fusarium solani (strain Fso14), which causes major problems for olive production in Tunisia and elsewhere. The project consists of two parts. In the first part, we have demonstrated that Ths97 is a biocontrol agent effective against the F. solani Fso14 pathogen. Induction of plant defence responses by Ths97 was shown to be partly responsible for the biocontrol effect. In vitro tests further showed that Ths97 develops mycoparasitic activities towards F. solani Fso14, by forming infection structures such as hyphae windings and wedges, appressoria and papillae. In the second part of the study, we investigated the Major Intrinsic Proteins (MIP) superfamily in the Trichoderma genus. This multigenic family has never been investigated in a hyperparasitic fungal species. Seven MIP members are present in T. harzianum, and are classified into 3 subgroups: AQP, AQGP and XIP. Their three-dimensional structures and their putative involvement in transport of water and certain polyols have been examined. Finally, their transcription profiles were monitored in Ths97 in planta in antagonistic situations and in vitro in a parasitic situation with Fso14 and show that 4 MIP are expressed and regulated differentially during the interaction. Our work has shown that Ths97 must be considered as a biological control agent and biostimulator of plant defences, and that MIPs are involved in the trophic relationships between T. harzianum and the environment. These data contributes to the further development of T. harzianum as an efficient biocontrol agent for sustainable protection of olive trees in Tunisia and around the world.
2

Communautés de nématodes phytoparasites associés à l'olivier : réponse aux forçages anthropiques et environnementaux / Plant-parasitic nematodes communities associated to olive trees : response to anthropogenic environmental and forcings

Ali, Nadine 08 October 2015 (has links)
Les interventions humaines de plus en plus fréquentes et persistantes dans les écosystèmes d'une part, et l'intensification des systèmes de cultures d'autre part qui s'accompagne pour partie de méthodes radicales pour combattre les bio-agresseurs des cultures, nous posent de multiples questions au sujet des risques écologiques liés aux changements des milieux, dont les perturbations induites sur les communautés d'organismes vivants. Les nématodes phytoparasites (NPP), vers ronds microscopiques telluriques qui occasionnent des pertes de production végétale importantes, sont partout présents en communautés. Ces nématodes répondent rapidement aux forçages extérieurs (e.g. anthropiques et environnementaux) par des modifications de la structure de leurs communautés. Par ce travail de thèse, nous cherchons à mieux comprendre l'effet des facteurs impliqués dans l'assemblage des espèces de NPP en communautés associées à l'olivier méditerranéen et à déterminer la réponse de ces communautés aux forçages imposés par la domestication de l'olivier, par l'intensification de sa culture et par différents facteurs environnementaux. L'étude a été réalisée au Maroc dans toutes les régions oléicoles (vergers traditionnels à faible densité et vergers à haute-densité), dans les zones refuge d'olivier sauvage (oléastre) et sur olivier féral. Les facteurs pédoclimatiques qui caractérisent les sites d'échantillonnage ont également été pris en considération. L'analyse de la nématofaune a révélé d'une grande diversité spécifique, de nombreuses espèces étant décrites pour la première fois sur olivier, et une nouvelle espèce (Meloidogyne spartelensis) ayant été découverte. La diversité, la composition taxonomique, trophique et fonctionnelle, la dominance des taxons, les patrons de communautés sont fortement affectés par les différents forçages pris en compte. Le gradient d'anthropisation croissante (sauvage vs féral vs cultivé traditionnel vs cultivé haute-densité) est la variable qui impacte le plus la diversité par réduction de la richesse spécifique et l'augmentation de l'abondance en NPP. L'étude a également porté une attention particulière sur la diversité des nématodes à galles des racines du genre Meloidogyne, un des principaux ravageurs de l'olivier. Elle a indiqué la dispersion de M. javanica dans les vergers et sur olivier féral, alors que d'autres espèces (M. arenaria, M. hapla et M. spartelensis) sont confinées dans les zones refuge des oléastres. Afin d'analyser la diversité génétique, des marqueurs morphologiques et moléculaires ont dévoilé d'une diversité importante entre et au sein des différentes populations de Meloidogyne. Les études diligentées dans le cadre de cette thèse confirment que la diversité et la structure des communautés de NPP pourraient être des indicateurs pertinents pour évaluer la santé des sols dans les agro et écosystèmes, en corrélant diversité et pathogénicité des communautés. Elles soulignent donc l'importance de la diversité parasitaire comme variable prioritaire à prendre en compte pour inspirer des stratégies de gestion des parasites basées sur le concept de résilience de la diversité (même s'il s'agit de parasites), pour une gestion durable des communautés de NPP et la préservation des milieux. / Human activities increasingly frequent and persistent in ecosystems on one hand, and cropping system intensification on the other hand partly with radical methods to control pests and diseases of crops, raise questions about the ecological risks related to biotop changes, including disturbances of living organism communities. Plant-parasitic nematodes (PPN), microscopic round soil-borne worms that cause significant losses of crop production, are everywhere present in communities. They respond quickly to external forces (e.g. human and environmental) by changing the structure of their communities. In this thesis, we seek to better understand the effect of the factors involved in the assemblage of PPN species in communities associated with the Mediterranean olive tree and to determine the response of these communities to forces imposed by olive domestication, by crop intensification and by various environmental factors. The study was conducted in all olive-growing regions in Morocco (traditional low density and high density orchards), in refugia areas for wild olive (oleaster) and on feral olive trees. The soil and climatic factors that characterize the sampling sites were also considered. The analysis of the nematofauna revealed a wide species diversity, many species being described for the first time on olive tree, and a new species (Meloidogyne spartelensis) have been discovered. The diversity, the species / trophic / functional structure of the communities, the dominance of the taxa, and the community patterns are strongly affected by the various forces considered. The increasing anthropogenic gradient (wild vs feral vs traditional cultivation vs high-density cultivation) is the variable that mostly impacts the diversity by reducing the species richness and increasing the abundance of PPN. A particular attention was attributed in this study to the diversity of root-knot nematodes Meloidogyne, a major pest of the olive tree. It revealed that M. javanica is widespread in orchards and olive feral, while other species (M. arenaria, M. hapla and M. spartelensis) are confined in oleaster refuge areas. In order to analyse the genetic diversity, morphological and molecular markers have revealed a significant diversity between and within different Meloidogyne populations. These thesis studies confirm that both the diversity and the structure of the PPN communities could be relevant indicators to assess soil health in agro and ecosystems, by correlating diversity and pathogenicity of communities. They therefore emphasize the importance of parasite diversity as a main variable to consider for inspiring pest control strategies based on the concept of diversity resilience (even if it concerns parasites) for sustainable management of PPN communities and for environment preservation.
3

El cultivo del olivo y la producción de aceite entre el Neolítico y el Imperio romano : el caso particular de la península Ibérica / La culture de l’olivier et La production oléicole du Néolithique à l’Empire romain : le cas particulier de la péninsule Ibérique / The culture of olive tree and the production of olive oil from the Neolithic Era to the Roman Empire : the case of the Iberian Peninsula

Bonora Andújar, Isabel 08 February 2016 (has links)
La culture de l’olivier et la production d’huile, du Néolithique à l’Empire romain : le cas particulier de la péninsule Ibérique. Ce titre met en lumière les deux axes principaux de cette recherche doctorale. La première concerne la domestication de la plante à partir des zones refuges de l’oléastre en Méditerranée ; la deuxième, l’apparition des différentes technologies de production oléicole, leur évolution, ainsi que les héritages observés entre les différents peuples du Bassin entre le Néolithique et l’Empire romain. Toutes ces problématiques sont analysées à partir du cas précis de la péninsule Ibérique, extrémité occidentale de la Méditerranée, lieu d’échanges et d’influences d’origine orientale – phéniciennes et grecques, principalement. Grâce à l’étude de la domestication et des premières implantations de l’olivier il a pu être mis en évidence la nécessité d’associer l’archéobotanique – identification d’endocarpes, du charbon de bois et du pollen – à la génétique. Cette dernière a récemment permis de démontrer l’autochtonie de la plante en Méditerranée occidentale depuis les dernières glaciations, contestant ainsi les théories diffusionnistes d’une origine phénicienne – exclusivement orientale – de l’espèce et de l’oléiculture. La deuxième partie consacrée à l’étude de la technologie oléicole péninsulaire, démontre l’importance d’une machinerie de type artisanal et local, contemporaine d’une mécanique de type « préindustrielle » d’origine orientale. Les deux groupes typologiques se complètent et s’influencent jusqu’à l’arrivée de l’industrie oléicole romaine. / The culture of olive tree and the production of olive oil from the Neolithic Era to the Roman Empire: the case of the Iberian Peninsula. The title highlights the two main research lines of this doctoral thesis. On the one hand, the domestication of the olive plant from the refuge areas of oleaster in the Mediterranean Sea; on the second hand, the emergence of different technologies of oil production, evolution and legacy observed between the different cultures of the Mediterranean from the Neolithic Era to the Roman Empire. All these issues are studied within the specific context of the Iberian Peninsula, western end of the Mediterranean world and place of exchanges and influences of from Eastern cultures - namely Phoenician and Greek. Through the study of domestication and first implantations of the olive tree emerged the need of involving scientific research from archaeobotany - identification of endocarps, wood charcoal and pollen - to genetics. The latter has recently demonstrated the indigeneity of the plant in West Mediterranean since the last glaciations, thus disputing the “diffusionist” theories of a Phoenician origin - exclusively Eastern - of the varieties of olive and their production. The second part of the research, dedicated to the study the Peninsular technology of olive oil, demonstrates the importance of craft and local machinery, as well as contemporary ‘preindustrial’ types of Eastern origin. Both typological groups complement and influence each other until the introduction of Roman olive industry.
4

The dialectics of global imperatives and local identities in Ethiopian teacher education

Teferi Bizuayehu Dorsis 11 1900 (has links)
The dialectics of globalization and multiculturalism is encountered everywhere and is an inescapable world reality. It has also become a major factor affecting teacher education. As a meeting ground and intercept for educational programs, teacher education provides an interface for both global imperatives and local identities. Ethiopia has pronounced achievements in most education programs at all levels, although official documents indicate variance in the quality of attainment across the levels (ESDP IV, 2011). Local studies (Ambisa, 2008; Amaliraj, 2008) also found that teacher education suffers from a lack of relevance and poor quality. Moreover, the demand for qualified teachers who are competent to shape the young generation through balancing the glocal context is increasing. This study investigated how local identities and global imperatives are integrated in contemporary Ethiopian teacher education at all levels. Critical theory was employed as the paradigm for the study. This epistemological view underpinned a discussion of the effect of globalization and multiculturalism on the world’s functioning. The research approach in the empirical study was qualitative and an interpretive case study method was employed. The units of analysis were literatures, such as The Lexus vs. the Olive Tree; McWorld vs. Jihad; The Clash of Civilization: The West vs. the Rest; and Demonstrating Common World Culture of Education (CWCE) or Locating A Globally Structured Agenda for Education (GSAE); and the contemporary Ethiopian teacher education programs (the PGDT and TESO programs). Data collection tools were basic dialectical questions under Eemeren’s (1986) established ‘system of norms’, observation, interviews and focus group discussions. Confidentiality, anonymity, informed consent, resolution of conflict of interest and intellectual ownership were considered in the study. The dialectical analysis investigated the four quadrant glocal relationships model and described the role players in each quadrant where nations may locate themselves. Moreover, the comparative analysis indicated that globalization has not yet become an issue in contemporary Ethiopian teacher education, while multicultural practices are fragmented and are addressed only in response to ethnic demands for accommodation. To this end, Ethiopian teacher education should redefine its programs in order to adjust to global understanding in an endeavor to produce competent teachers for the global market. / Curriculum and Instructional Studies / D. Ed. (Curriculum Studies)
5

The dialectics of global imperatives and local identities in Ethiopian teacher education

Teferi Bizuayehu Dorsis 11 1900 (has links)
The dialectics of globalization and multiculturalism is encountered everywhere and is an inescapable world reality. It has also become a major factor affecting teacher education. As a meeting ground and intercept for educational programs, teacher education provides an interface for both global imperatives and local identities. Ethiopia has pronounced achievements in most education programs at all levels, although official documents indicate variance in the quality of attainment across the levels (ESDP IV, 2011). Local studies (Ambisa, 2008; Amaliraj, 2008) also found that teacher education suffers from a lack of relevance and poor quality. Moreover, the demand for qualified teachers who are competent to shape the young generation through balancing the glocal context is increasing. This study investigated how local identities and global imperatives are integrated in contemporary Ethiopian teacher education at all levels. Critical theory was employed as the paradigm for the study. This epistemological view underpinned a discussion of the effect of globalization and multiculturalism on the world’s functioning. The research approach in the empirical study was qualitative and an interpretive case study method was employed. The units of analysis were literatures, such as The Lexus vs. the Olive Tree; McWorld vs. Jihad; The Clash of Civilization: The West vs. the Rest; and Demonstrating Common World Culture of Education (CWCE) or Locating A Globally Structured Agenda for Education (GSAE); and the contemporary Ethiopian teacher education programs (the PGDT and TESO programs). Data collection tools were basic dialectical questions under Eemeren’s (1986) established ‘system of norms’, observation, interviews and focus group discussions. Confidentiality, anonymity, informed consent, resolution of conflict of interest and intellectual ownership were considered in the study. The dialectical analysis investigated the four quadrant glocal relationships model and described the role players in each quadrant where nations may locate themselves. Moreover, the comparative analysis indicated that globalization has not yet become an issue in contemporary Ethiopian teacher education, while multicultural practices are fragmented and are addressed only in response to ethnic demands for accommodation. To this end, Ethiopian teacher education should redefine its programs in order to adjust to global understanding in an endeavor to produce competent teachers for the global market. / Curriculum and Instructional Studies / D. Ed. (Curriculum Studies)
6

L’histoire de l’olivier et de l’huile d’olive en Corse de la fin du XVIème siècle au début du XXème siècle – Economie – Société – Aspects culturels / The history of olive and olive oil in Corsica from the end of the sixteenth century to the beginning of the twentieth century – Economy – Society – Cultural Aspects

Jouffroy, Denis 09 April 2013 (has links)
L’histoire de l’olivier et de l’huile d’olive est indissociable de l’histoire de l’agriculture corse. La réalité historique de la culture de l’olivier et de la production d’huile a été appréhendée à partir de la fin du XVIe siècle jusqu’à la veille de la première guerre mondiale. Le paysage oléicole a connu un grand développement à l’époque moderne sous l’impulsion de la Sérénissime République de Gênes ; il s’est poursuivi au XIXe siècle sous l’autorité de l’administration française. L’étude de l’ensemble des microrégions de l‘île a mis en évidence le rôle majeur joué par les communautés dans l’économie oléicole insulaire. On parle d’une diversité et non d’une unicité de l’olivier en Corse : diversité des variétés, des pratiques culturales, des modes d’extraction de l’huile, des paysages… L’impact économique de cette culture durant la période étudiée a été très important pour la Corse. L’olivier est au cœur des préoccupations des hommes, il a transformé partiellement l’agriculture, les paysages, les infrastructures de transports, l’architecture rurale et a participé à l’émergence d’une société microrégionale originale. / The olive tree and olive oil's history is inseparable from the History of the Corsican agriculture. The real nature of the culture of the olive tree and the production of the olive oil have been comprehended from the end of the XVIth century to the eve of the first world war. The olive landscape knew a great development during the modern age with the Serene highness Republic of Genoa; it pursuded on the XIXth century under the authority of the French administration. The study on the whole microregions of the island higlights the main part played by the comunities in the oleicol economy of the island. Concerning the olive tree in Corsica we notice an important diversity of trees not an uniquiness: diversity of the sorts of trees, of the cultural pratices, of ways to extract the oil, of landscapes... the economic impact of this culture during the era studied had been really important for Corsica. The olive tree is at the heart of the humans' concerns, it partially transformed the agriculture, the landscapes and the substructure of the transports, the rural architecture and took part in the emergence of an original regional micro society. / A storia di l'alivu è di l'oliu d'aliva hè propiu ligata à a storia di l'agricultura corsa. A realità storica di a cultura di l'olivu è di a produzzione d'oliu hè stata studiata da a fine di u XVIe seculu finu à a prima guerra mundiale. U paisaghju d'alivi hà cunnisciutu un grande sviluppu durante l'epica muderna per via di l'abbrivu datu da a Republica di Genuva. S'hè perseguitu durante u XIXe seculu sottu à l'autorità di l'admministrazione francesa. U studiu di l'inseme di a rughjoni di l'isula hà dimustratu a funzione maestra di e communità in l'ecunumia à partesi di a cultura di l'alivi. Si parla d'una diversità è micca d'un'unicità di l'alivu in Corsica : diversità di e varietà, di e pratiche culturale, di e manere per fragne l'alive, di i paisaghji... U pesu ecunomicu di sta cultura durante u periodu studiatu hè statu assai impurtante per a Corsica. L'alivu face parte di e riflessione di l'omi. Hà cuntribuitu à transfurmà l'agricultura, i paisaghji, l'infrastrutture di i trasporti, l'architettura campagnola è hà participatu ancu à a nascita d'una sucetà micro regiunale originale.

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