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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.
11

Isolation of an ARGONAUTE gene in pelargonium and identification of candidate genes regulated through ARGONAUTE4-dependent RNA-dependent DNA methylation in Arabidopsis /

He, Jie. January 2009 (has links)
Dissertation (Ph.D.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for the Doctor of Philosophy degree in Biology." Bibliography: leaves 54-56, 91-95, 118-119, 133-139.
12

The effect of geography, cultivation and harvest technique on the umckalin concentration and growth of pelargonium sidoides (Geraniaceae) /

White, Andrew Graeme. January 2006 (has links)
Thesis (M.Sc. (Botany)) - Rhodes University, 2007.
13

Effect of water stress and arbuscular mycorrhiza on the plant growth and antioxidant potential of Pelargonium reniforme Curtis and Pelargonium sidoides DC

Ingarfield, Patricia Jean January 2018 (has links)
Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018. / Pelargoniums have been studied extensively for their medicinal properties. P. reniforme and P. sidoides in particular are proven to possess antimicrobial, antifungal and antibiotic abilities due to their high antioxidant potential from compounds isolated from their tuberous roots. These plants have now been added to the medicine trade market and this is now causing concern for conservationists and they are generally harvested from the wild populations. This study evaluated the effect of water stress alone and in conjunction with arbuscular mycorrhiza on two species of Pelargoniums grown in a soilless medium. The experiment consisted of five different watering regimes which were applied to one hundred plants of each species without inoculation with arbuscular mycorrhiza and to one hundred plants of each species in conjunction with inoculation with AM. All the plants in the experiment were fed with a half-strength, standard Hoagland nutrient solution at varying rates viz. once daily to pot capacity, every three days to pot capacity, every six days to pot capacity, every twelve days to pot capacity and every twenty-four days to pot capacity. The objectives of the study were to measure the nutrient uptake, SPAD-502 levels (chlorophyll production) and metabolite (phenolics) formation of both species, grown under various rates of irrigation and water stress, as well with or without the addition of arbuscular mycorrhiza at planting out. Each treatment consisted of 10 replicates. SPAD-502 levels were measured weekly using a hand held SPAD-502 meter. Determination of nutrient uptake of macronutrients N, K, P, Ca, Mg and Na and micronutrients Cu, Zn, Mn, Al and B were measured from dry plant material at the end of the experiment by Bemlab, 16 Van Der Berg Crescent, Gants Centre, Strand. Plant growth in terms of wet and dry shoot and root weight were measured after harvest. Determination of concentrations of secondary metabolites (phenolic compounds) were assayed and measured spectrophotometrically at the end of the experiment. The highest significant reading of wet shoot weight for P. reniforme was taken in treatments 1 and 2 with and without mycorrhiza i.e. WF1, WF1M, WF2 and WF2M, with the highest mean found in WF1 with no mycorrhiza. This indicates that under high irrigation AM plays no part in plant growth, possibly due to leaching. More research is necessary in this regard. With regard to wet root weight, this was found to be not significant in any of the treatments, other than the longest roots being found in WF4. Measurements for dry root weight showed that WF1,2,3 and 5 were the most significant at P≤ 0.001 significance, with the highest weight found at treatment being WF3 and WF3M. The highest mean of shoot length of the plants was measured in treatment WF2 at moderate watering, but no statistical difference was found with water application and mycorrhiza addition. Nutrient uptake was increased in P. sidoides in all the different watering levels in the experiment except in the uptake of Mg. AM inoculation showed an increase in the uptake of Ca, while absorption of N occurred at higher water availability. K uptake was enhanced by the addition of AM in high water availability and K utilisation decreased as water stress increased. Medium to low watering resulted in higher leaf content in P. sidoides while the interaction between water availability and AM inoculation increased chlorophyll production towards the end of the experiment.
14

Development of a quality control protocol for Pelargonium sidoides DC using Fourier transform infrared spectroscopy.

Maree, Johanna Elizabeth. January 2009 (has links)
Thesis (MTech. degree in Pharmaceutical Sciences)--Tshwane University of Technology, 2009. / Quality control procedures are vital in the pharmaceutical industry to guarantee the authenticity and quality of products. A major challenge in quality assurance of herbal material is the vast variation of active constituents in plants from the same species. As a result of this variation, the selection of only a few compounds as criteria for quality control is inadequate. Pelargonium (P.) sidoides is indigenous to South Africa and highly valued by traditional healers as a remedy to treat coughs, upper respiratory tract irritations and gastrointestinal conditions. An ethanolic extract of P. sidoides is used in the proprietary herbal tincture known as Umckaloabo®. The composition and concentration of polyphenols are parameters which determine the quality of this herbal medicine because it provides several therapeutic benefits in the non-specific medicinal treatment of infectious diseases. Despite the commercial development of P. sidoides very few studies have been conducted to document the full phytochemical range of variation for natural populations and no study has been published on the development of a fast accurate quality control method for the validation of raw material.
15

The effect of geography, cultivation and harvest technique on the umckalin concentration and growth of pelargonium sidoides (Geraniaceae)

White, Andrew Graeme January 2007 (has links)
Pelargonium sidoides DC. (Geraniaceae) root extracts are used in the Eastern Cape Province of South Africa as a traditional medicine for the treatment of respiratory tract and gastro-intestinal infections. Ethanolic extracts are used globally as herbal treatments for bronchitis, asthma and as an immune system booster. Despite documented exploitation of wild populations by illegal harvesters, this species has not been awarded a protected status. The high level of harvest in the years preceding this study prompted this investigation of the prospects for sustainable root harvest through wild harvest and greenhouse cultivation. A novel method was developed for the purification of umckalin, a bioactive constituent in root extracts, such that the root umckalin concentrations of wild and cultivated plants could be quantified by HPLC. As part of the cultivation experiments, the concentration of umckalin in roots was measured for plants across part of the species’ distribution range in the Eastern Cape Province. This survey revealed that root umckalin concentrations were inversely related to the average annual rainfall of the collection site (r² = 0.94, p = 0.007) and directly related to soil pH (r² = 0.97, p = 0.002). Thus, the possibility of inducing high umckalin concentrations in greenhouse-cultivated plants was investigated by subjecting plants to rapid and prolonged water stress treatments. Two leaf applied hormone treatments (cytokinin and gibberellin) and a root competition treatment with a fast growing annual (Conyza albida) were also investigated based on the potential function of umckalin in P. sidoides plants. These five treatments did not significantly affect root umckalin concentrations compared to well-watered controls. The results of further experiments suggested that umckalin production may have been influenced by the geographical origin and genetics of plants rather than environmental variation. Following wild harvest experiments, the regrowth of replanted shoots from which a standard proportion of the root was harvested showed that water availability affected shoot survival but not root regrowth rate. Regrowth rates were low, questioning the viability of wild harvest. In contrast, greenhouse cultivated plants showed ca. six times greater growth rates, supporting the cultivation of roots to supply future market demand.
16

Evaluation of the effect of Pelargonium reniforme Curtis extract on alcohol induced liver damage in Nkonkobe Municipality Eastern Cape Province South Africa

Adewusi, Emmanuel Adekanmi January 2009 (has links)
Alcohol abuse is a very common practice (just like in many other parts of the world) in Nkonkobe Municipality, Eastern Cape Province, South Africa. This is associated with liver disease. An ethnobotanical survey of plants used for the treatment of alcohol-induced liver damage in Nkonkobe Municipality was conducted. During the survey and also from information gathered in the literature, Pelargonium reniforme Curtis, was prominently mentioned, among other plants, as the species used generally for the treatment of alcohol-induced liver damage. This project was designed to evaluate the effects of the plant on alcohol-induced liver damage, including its antioxidant and antimicrobial properties. It also involves safety evaluation studies to determine if the plant is safe for consumption. Studies using rats of the Wistar strain were carried out to determine the protective and curative effects of P. reniforme on alcohol-induced liver damage. Results obtained showed that the plant extract can protect the liver cells as well as enhance recovery from tissue damage. The plant also showed good antimicrobial and antioxidant activity and this further validates its use in the treatment of liver diseases. Safety evaluation studies of the extract were carried out by investigating the effects of the oral administration on some haematological and biochemical parameters in male Wistar rats. The results obtained from the study suggest that the plant extract is not toxic at the doses used and is therefore safe for medicinal uses. The results of the various bioassays carried out in this project have justified the traditional uses of P. reniforme for the treatment of alcohol-induced liver damage.
17

The protection of indigenous knowledge within the current intellectual property rights regime: a critical assessment focusing upon the Masakhane Pelargonium case

Msomi, Zuziwe Nokwanda January 2013 (has links)
The use of indigenous knowledge (IK) and indigenous bio-resources by pharmaceutical and herbal industries has led to concerns about the need to protect IK in order to prevent biopiracy and the misappropriation of indigenous knowledge and resources. While some commentators believe that intellectual property rights (IPR) law can effectively protect IK, others are more sceptical. In order to contribute to the growing debate on this issue, this study uses the relatively new and as yet largely critically unanalysed Masakhane Pelargonium case to address the question of whether or not IPR law can be used to effectively protect IK. It is argued here that discussion about the protection of IK is a matter that must be located within broader discussions about North-South relations and the continued struggle for economic and political freedom by indigenous people and their states. The Masakhane case suggests that IPR law in its current form cannot provide sufficient protection of IK on its own. Incompatibilities between IPR law and IK necessitate that certain factors, most important of which are land, organised representation, and what are referred as 'confidence and network resources', be present in order for IPR law to be used with any degree of success. The study also reveals various factors that undermine the possibility of using IPR law to protect IK. In particular, the study highlights the way in which local political tensions can undermine the ability of communities to effectively use IPR law to protect their knowledge. The thesis concludes with several recommendations that will enable indigenous communities and their states to benefit more substantially from the commercialisation of their bio-resources and associated IK.

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