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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

Ethylene sensitivity : the roles of polyamines and short-chain saturated fatty acids in petunia and cyclamen flowers

Van Wyk, Marie Louise 01 October 2014 (has links)
M.Sc. (Botany) / Please refer to full text to view abstract
2

A comparison of growth media on cyclamens in a controlled environment

Adriaanse, Pierre 08 July 2014 (has links)
Cyclamens are deemed an essential cold season crop for supplementing the income of commercial growers during winter. However, cyclamens have the reputation of being a demanding commercial crop mainly due to difficulty in successful crop cultivation, lengthy production time and production costs. The economic and environmental landscape in South Africa dictates that careful consideration be given to reducing production time and costs, but still improving the quality of the commercial crop for market readiness. Growth medium are considered an important factor contributing significantly to the quality of commercially grown container cyclamens in a controlled environment. The focus of this study was on establishing the most suitable growth medium for commercially grown cyclamens in a South African environment in order to improve the quality of the commercial crop. Only one F1 variety of cyclamen was used as the sample population with a sample size of five plants per growth medium mixture planted according to a randomised block design in a specified area within a greenhouse. Seven commercially available growth medium mixtures, five locally available and two imported, were subjected to a typical production cycle of commercial cyclamens in a controlled greenhouse. The growth medium mixtures for comparison were Cyclamen Mix; 45 Mix; 50% Cyclamen Mix - 50% 45 Mix; 49 Mix; 7 Mix; coarse coir; Klasmann base 4 Substrate mix . The measuring instrument used in the study was adapted from existing instruments used in the comparison of cyclamens and growth medium. It included various measurements and observations: Plant height, plant diameter, plant weight, number of leaves, leaf width, foliage fresh weight, number of flowers, diameter of tuber and root fresh weight. The results obtained in the comparison determine the most suitable growth medium for container cyclamens for South African circumstances. The physical properties of peat retain water for a longer time which is beneficial for the production of container cyclamen. The results of this study therefore indicate that growth mediums containing peat performed better than mediums containing no peat. / Agriculture and  Animal Health / M.Sc. (Ornamental Horticulture)
3

A Digital Method of Measurement and a Logistic Growth Model for the Blooming Angle of Miniature Roses and their Application on Cyclamen and Hyacinth

Luo, Violet 01 May 2009 (has links)
In this project, the angles of miniature rose petals throughout the course of their bloom were measured with a digital protractor constructed using a function plotting software. The angle was then modeled as a function of time, and an analogy was drawn from the blooming of rose petals to the logistic growth of populations. The digital method of measurement and the logistic growth model were also applied to cyclamen and hyacinth petals.
4

A comparison of growth media on cyclamens in a controlled environment

Adriaanse, Pierre 08 July 2014 (has links)
Cyclamens are deemed an essential cold season crop for supplementing the income of commercial growers during winter. However, cyclamens have the reputation of being a demanding commercial crop mainly due to difficulty in successful crop cultivation, lengthy production time and production costs. The economic and environmental landscape in South Africa dictates that careful consideration be given to reducing production time and costs, but still improving the quality of the commercial crop for market readiness. Growth medium are considered an important factor contributing significantly to the quality of commercially grown container cyclamens in a controlled environment. The focus of this study was on establishing the most suitable growth medium for commercially grown cyclamens in a South African environment in order to improve the quality of the commercial crop. Only one F1 variety of cyclamen was used as the sample population with a sample size of five plants per growth medium mixture planted according to a randomised block design in a specified area within a greenhouse. Seven commercially available growth medium mixtures, five locally available and two imported, were subjected to a typical production cycle of commercial cyclamens in a controlled greenhouse. The growth medium mixtures for comparison were Cyclamen Mix; 45 Mix; 50% Cyclamen Mix - 50% 45 Mix; 49 Mix; 7 Mix; coarse coir; Klasmann base 4 Substrate mix . The measuring instrument used in the study was adapted from existing instruments used in the comparison of cyclamens and growth medium. It included various measurements and observations: Plant height, plant diameter, plant weight, number of leaves, leaf width, foliage fresh weight, number of flowers, diameter of tuber and root fresh weight. The results obtained in the comparison determine the most suitable growth medium for container cyclamens for South African circumstances. The physical properties of peat retain water for a longer time which is beneficial for the production of container cyclamen. The results of this study therefore indicate that growth mediums containing peat performed better than mediums containing no peat. / Agriculture and  Animal Health / M.Sc. (Ornamental Horticulture)
5

Cyclamen persicum Mill. - průzkum světového sortimentu

Žďárská, Zuzana January 2013 (has links)
No description available.
6

Ausprägung wichtiger Eigenschaften für die generative Vermehrung einer gartenbaulichen Modell-Kultur unter dem Einfluss von Genotyp und Umwelt

Ghanem, Ghofran 18 November 2011 (has links)
Die vorliegende Arbeit prüft bei der gärtnerischen Modell-Kultur Cyclamen den Einfluss des Genotyps (interspezifische Hybriden) auf generative Merkmale sowie bei C. persicum `Melody´ den Einfluss von Kultivierungsmaßnahmen wie die Besiedelung der Wurzeln durch einen symbiontischen Pilz (Piriformospora indica) in Kombination mit einem differenzierten Phosphor-Angebot auf vegetative und generative Merkmale: (1) Pflanzendurchmesser, (2) Blühzeitpunkt und Blütenanzahl, (3) Anzahl Samenanlagen pro Fruchtknoten, (4) Vitalität von Pollen und Samenanlagen, (5) Mikrosporogenese, (6) Befruchtungsvorgang (Pollenschlauchwachstum, Anteil Fruchtknoten mit Pollenschläuchen, Anzahl Pollenschläuche im Griffel und Penetration der Pollenschläuche in die Micropyle), (7) abortierte Blüten nach der Bestäubung (8) Samenbildung und (9) Samenanzahl. / The present paper investigates Cyclamen as an horticultural model-culture. A main Focus is on the characteristics of the Cyclamen genotype, notably with interspecific hybrids. Further, Cyclamen persicum cv. served as a model to analyse effects on parameters of pollination, seed development and number of ovules per ovary, which are caused by a root colonization of the seed bearer with the symbiotic fungus Piriformospora indica (Piri) in combination with a differentiated phosphorus supply. In this regard, plant diameter, flowering time and flower number, the viability of pollen and ovules, the microsporogenesis, the growth of pollen tubes, the seed formation and the seed count were considered among important parameters of pollination and seed development.
7

Isolement et caractérisation de saponosides extraits de deux plantes médicinales : Cyclamen africanum, Zygophyllum cornutum et évalution de leur activité anti-inflammatoire / Isolation and characterization of two saponosides extracts herbs Cyclamen africanum, Zygophyllum cornutum and assessment of their anti-inflammatory activity

Betina-Bencharif, Soumeya 13 October 2014 (has links)
L’apparition de plusieurs maladies, telles que le cancer, le diabète, l'hypertension artérielle et la propagation d'infections de type virus mutagènes peuvent être liées à la qualité et au mode de vie que nous menons aujourd’hui. En effet, plusieurs études sur les facteurs déclenchant ces maladies dites "morbides" à long ou à court terme, sont liées au stress et à la qualité des aliments consommés, qu'ils soient d'origine végétale ou animale. Ces maladies deviennent un phénomène courant, elles touchent différentes races et toutes les catégories de la société. D'après les recherches ethnobotaniques, les substances d’origine naturelle, ont permis à des civilisations de survivre à des maladies mortelles. A titre d'exemple, on retrouve ainsi des références à des périodes de fièvre paludique en Chine et à des symptômes de cette maladie dans le «Huangdi Neijiang» Le Canon de Médecine datant des environs du premier siècle avant notre ère, plus de 2000 ans, qui relate de l'emploi de plantes médicinales, pour soulager les fièvres (Desgrouas et al., 2014).Vers 186 avant J.-C. apparaît, dans certaines régions de Chine, l'utilisation en tisane, du Qing hao su, appelé plus tard artémisinine en Occident et extrait d'une plante médicinale utilisée comme antipyrétique appelée "Qing hao", Artemisia annua ou Armoise annuelle. L'artemisinine bloque une enzyme qui permet au parasite de pomper le calcium et l'empêche ainsi de se développer. Au jour d'aujourd'hui l’Artemisinin-based combination therapy, en français Thérapie combinée à base d'artémisinine et en sigle ACT, est une thérapie et une prévention tertiaire dans les cas de paludisme simple.Dans cette optique notre étude vient s'ajouter à une longue série d'études menées sur les plantes médicinales et les substances naturelles extraites. Elle a pour objectif de révéler de nouvelles biomolécules, de mettre en évidence leurs activités biologiques grâce à des techniques de biotechnologies d'une part. D'autre part ces investigations permettront de valoriser les ressources naturelles qui se distinguent par leur endémicité.Pour se faire, notre choix s'est porté sur deux plantes médicinales endémiques à l'Algérie Cyclamen africanum Boiss. & Reuter et Zygophyllum cornutum Coss. , après une recherche ethnobotanique sur la pharmacopée traditionnelle du Nord de l'Afrique, et qui a révélé l’efficacité de ces plantes dans les problèmes inflammatoires minimes chez les autochtones, nous avons entrepris des investigations pharmaco- biochimiques.Ces dernières nous ont permis d'isoler : cinq composés à partir de l'extrait méthanolique des racines de l'espèce Cyclamen africanum Boiss. & Reuter, deux nouvelles saponines triterpéniques de type Oleanane, Afrocyclamin A et B (1, 2), ainsi que trois saponines triterpénoïdes connus sous le nom de lysikokianoside (3), deglucocyclamin I (4) et de son dérivé d'acide dicrotalique (5); et Sept saponosides connus à partir de l'extrait méthanolique de la plante entière de Zygophyllum cornutum Coss., ces saponosides sont de type ursane, ce type de triterpène est rapporté dans cette espèce pour la première fois et peuvent être considérés comme un marqueur chimio-taxonomique (chemotype) du genre Zygophyllum. Les structures ont été élucidées, sur la base de l'analyse des spectres de l'expérience RMN-1D et RMN- 2D (COSY, TOCSY, NOESY, HMBC et HSQC) et spectrométrie de masse en source FAB mode ion négatif. Des activités biologiques, des fractions saponosidiques Fr.1 et Fr.2, ont été testées sur des lignées de Rats mâles et femelles, de la race Winstar pour évaluer l'activité anti inflammatoire.La fraction saponosidique Fr.1 de Cyclamen africanum à la dose 5 mg, a montré un effet significatif sur l'inflammation causé par la carragénine, en réduisant l'oedème et la réponse immunitaire, qui s'est traduite par la concentration des protéines de la réponse inflammatoire (PRI) à travers leurs action sur les pro-médiateurs de l'inflammation (COX-2, PGE2, TNF -α, iNOS). / The appearance of several diseases, such as cancer, diabetes, high blood pressure and spread of infections mutagenic virus type can be linked to the quality and lifestyle that we lead today. Indeed, several studies on the factors triggering these so-called "morbid" long-or short-term illnesses are related to stress and quality of food consumed, whether of plant and animal origin. These diseases are becoming a common occurrence, they affect different races and all classes of society. According ethnobotanical research, naturally occurring substances, allowed civilizations to survive deadly diseases. For example, we thus find references to periods of malarial fever in China and one of the symptoms of this disease in the "Huangdi Neijiang" The Canon of Medicine dating from around the first century BC, more than 2000 years, which relates to the use of herbal medicines to relieve fevers (Desgrouas et al., 2014).Around 186 BC appears, in some parts of China, the use in herbal tea, Qing hao su, later known as artemisinin in the West and extracted from a medicinal plant used as antipyretic called "Qing hao" Artemisia annua or annual wormwood. Artemisinin blocks an enzyme which enables the parasite to pump calcium and prevents it from developing. As of today the Artemisinin-based combination therapy in French Combination therapy of artemisinin and ACT acronym, is a therapy and tertiary prevention in cases of uncomplicated malaria.From this perspective our study adds to a long series of studies on medicinal plants and natural substances extracted. It aims to reveal new biomolecules, highlighting their biological activities through techniques of biotechnology on the one hand. Moreover, these investigations will develop natural resources that are characterized by endemic.To do this, our choice is focused on two endemic medicinal plants in Algeria Cyclamen africanum Boiss. & Reuter and Zygophyllum cornutum Coss. After an ethnobotanical research on traditional medicine in Northern Africa, which showed the effectiveness of these plants in minimal inflammatory problems among Aboriginal, we undertook biochemical pharmacological investigations.The latter allowed us to isolate, five compounds from the methanol extract of the roots of the species Cyclamen africanum Boiss. Reuter & two new oleanane triterpene saponins type, Afrocyclamin A and B (1, 2) and three triterpenoid saponins known lysikokianoside of (3), deglucocyclamin I (4) and its derivative dicrotalique acid (5) September and known from the methanol extract saponins from the whole plant of Zygophyllum cornutum Coss. these saponins are ursane type, type triterpenes are reported in this species for the first time and can be considered a chemotherapy marker Taxonomic (chemotype) of Zygophyllum kind. The structures were elucidated on the basis of the analysis of NMR spectra of the experience-1D and 2D-NMR (COSY, TOCSY, NOESY, HSQC and HMBC) and mass spectrometry method negative ion FAB source. The biological activities of saponosidiques FR.1 and Fr.2 fractions were tested on lines of male and female rats of the Winstar rats to evaluate the anti-inflammatory activity. The saponosidique fraction FR.1 Cyclamen africanum the 5 mg dose, showed a significant effect on inflammation caused by carrageenan, reducing edema and immune response, which resulted in the concentration of protein the inflammatory response (PRI) through their action on the pro-inflammatory mediators (COX-2, PGE2, TNF -α, iNOS). The fraction of Fr.2 saponosidique Zygophyllum dose 20 mg did not show a significant effect on inflammation in general.
8

Fusariose du cyclamen : détection préventive du risque et contrôle biologique / Fusarium wilt of cyclamen : early detection and biocontrol

Lecomte, Charline 19 May 2016 (has links)
La fusariose vasculaire du cyclamen est une maladie causée par le champignon tellurique Fusarium oxysporum f. sp. cyclaminis. Elle est considérée comme l’une des maladies les plus graves du cyclamen et se traduit par des pertes atteignant jusqu’à 50 % de la production. Actuellement, les moyens de lutte ne permettent pas de contrôler la maladie. Dans ce contexte, une collaboration s’est engagée entre l’institut technique de l’horticulture, Astredhor, représentant les producteurs, l’INRA de Dijon pour son expertise sur F. oxysporum et la société Agrene pour son expertise en lutte biologique. Les objectifs de cette collaboration étaient doubles : i) identifier un marqueur spécifique de la forme spéciale cyclaminis et développer un outil de détection de l’agent pathogène permettant de mettre en place des méthodes de lutte appropriées ; ii) identifier un agent de lutte biologique efficace contre le pathogène. Le travail s’est donc structuré autour de ces deux objectifs.Une collection de souches représentatives de la diversité des populations de F. oxysporum f. sp. cyclaminis a été constituée. Elle regroupe des souches provenant de collections internationales et des isolats obtenus de cyclamens symptomatiques ou non. L’analyse moléculaire de cette collection a permis de caractériser son importante diversité génétique et a mis en exergue la difficulté d’identifier un marqueur moléculaire spécifique. Néanmoins, un fragment d’ADN spécifique de l’agent pathogène a pu être mis en évidence par amplification aléatoire d’ADN polymorphe. A partir de ce fragment, un couple d’amorces spécifiques a été dessiné et un outil moléculaire a été développé. Ce dernier permet une détection du champignon in planta en PCR conventionnelle et en PCR en temps réel.Parallèlement, une étude bibliographique approfondie relative aux méthodes de lutte biologique contre les fusarioses induites par F. oxysporum sur les plantes ornementales a été effectuée. Cette revue a souligné la possibilité d’utiliser des ressources d’origine microbienne et d’origine végétale pour contrôler F. oxysporum, mais cette stratégie impliquant une étape de sélection nous est apparue lourde et laborieuse. Nous avons opté pour une autre démarche visant à identifier, parmi des produits déjà sur le marché, ceux susceptibles de réduire significativement la gravité de la maladie. Des bioessais ont été conduits en serre, dans des conditions proches de celles de la production pour tester sept produits reposant sur la formulation de bactéries, de champignons ou de combinaisons de ces microorganismes. Les produits les moins performants ont été éliminés à l’issue d’un premier essai. Des bioessais ont été conduits à nouveau avec trois produits. Un seul de ces produits donne satisfaction mais son efficacité devra être validée en conditions de production réelles.En conclusion, l’outil de détection spécifique permettra aux producteurs de s’assurer de la qualité sanitaire de la culture et des supports de culture. L’agent de lutte biologique retenu à l’issue de nos essais permettra dans un premier temps aux producteurs de prévenir le risque d’activité infectieuse de F. oxysporum f. sp. cyclaminis. Cependant, un travail de recherche d’un agent de lutte plus performant s’avère nécessaire. Des pistes sont proposées. / Fusarium wilt of cyclamen is one of the most damaging diseases of cyclamen. The causal agent, Fusarium oxysporum f. sp. cyclaminis, is a soil-borne fungus. Losses can reach more than 50 % of the production. Several methods of control are available, but none of them offer an efficient and environmentally friendly solution. In this context, a project was developed in collaboration with the French institute of horticulture, Astredhor, which represents the producers, the INRA of Dijon, for its expertise on F. oxysporum and the company Agrene for its expertise in biological control. The project has two goals: i) design a molecular marker specific of Fusarium oxysporum f. sp. cyclaminis allowing a better management of the disease, ii) identify one or several efficient biological control agents.A collection of strains representative of the diversity of F. oxysporum f. sp. cyclaminis populations was made up with strains from international collections and isolates collected from symptomatic and asymptomatic cyclamens. A molecular study of the collection demonstrated the high genetic diversity of the forma specialis, which makes the identification of a specific molecular marker more complicated. However, a specific DNA fragment was identified by random amplified polymorphic DNA. A primer pairs was designed and a specific tool of detection was developed. Thanks to this tool, it is now possible to detect the fungus in planta by conventional and real-time PCR.Simultaneously, a broad literature analysis on the biocontrol of ornamental plant diseases caused by F. oxysporum was performed. The review emphasized that biocontrol of F. oxysporum encompassed both microbial biocontrol agents and botanicals. To avoid the laborious and time-consuming screening step, we decided to assess the antagonistic activity of seven commercial products containing bacteria, fungi or a combination of both microorganisms. Greenhouse trials were performed under conditions similar to those of the production. First trial led to the exclusion of the less efficient products. Other trials were conducted with the three remaining products. Disease reduction was obtained with one of these products although it must be validated in production.Finally, the molecular tool of detection will allow producers to insure the health status of the culture. In addition, the efficient biocontrol agent identified will prevent the disease progress for a while but more investigations are needed to obtain reliable, efficient and sustainable biocontrol agents. Proposals to improve Fusarium wilt control are discussed.

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