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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

A taxonomic study of the type section of the genus Lebeckia Thunb.(Fabaceae, Crotalarieae)

Le Roux, Margaretha Marianne 13 June 2008 (has links)
A taxonomic study of the type section of the genus Lebeckia Thunb. (sect. Lebeckia; syn. Eu-Lebeckia Benth., Phyllodiastrum Walp.) is presented. The genus Lebeckia (Fabaceae, Crotalarieae) is endemic to the western parts of southern Africa and the type section is endemic to the Cape Floristic Region. Species delimitations and relationships within the sections of the genus are not clear and are in urgent need of a revision since the genus has not been studied in its entirety for nearly 150 years. Lebeckia section Lebeckia, now consists of 14 species, all with acicular (needle-shaped) leaves. Based on fruit morphology, four informal species groups have here been distinguished within the section. An analysis of morphological characters revealed the existence of four undescribed species, namely “L. brevicarpa” M.M.le Roux and B-E.van Wyk sp. nov. ined., [previously confused with L. sepiaria (L.) Thunb.], “L. brevipes” M.M.le Roux and B-E.van Wyk sp. nov. ined., (hitherto confused with L. longipes Bolus and L. pauciflora Eckl. and Zeyh.), “L. uniflora” B-E.van Wyk and M.M.le Roux [previously confused with L. wrightii Bolus] and “L. zeyheri” M.M.le Roux and B-E.van Wyk [previously considered to be a variety of L. plukenetiana E.Mey.] A key to the 14 species of section Lebeckia is presented. Diagnostic characters, nomenclature, typification and distribution maps of all the species are presented, discussed and illustrated. Morphological data was used in a cladistic analysis and resulted in a partially resolved cladogram, confirming the presence of four (presumably monophyletic) groups within the section. In a molecular systematic study, four DNA sequences were used to explore relationships, but the resolution was low and unsatisfactory and the result only partially supported the hypothesis based on morphological characters. However, the molecular phylogeny agreed with the morphological analysis in providing convincing support for the monophyly of the section. / Prof. B.E. van Wyk
2

Isolation of an anti-HIV compound from Elaeodendron croceum (Thunb.) DC.

Prinsloo, Gerhard 08 June 2007 (has links)
HIV/AIDS threaten more than 40 million people worldwide and more than 5 million in South Africa alone. There is no cure for the disease yet, and novel drugs need to be discovered to make any progress in combating the disease. Twelve extracts from indigenous South African plants were analysed, of which one, Elaeodendron croceum, showed exceptionally good inhibition of transcription factors and a recombinant HIV strain in the HeLa-TAT-Luc and MT-2 VSV-pseudotyped recombinant virus assays. The pure compound isolated from this extract seemed to be the most toxic of all the samples, with toxicity of only 25% at a concentration of 100 _g/ml. When the concentration is increased, the toxicity increased slowly from 15% at a concentration of 0.195 _g/ml until it reached 25% toxicity at a concentration of 100 _g/ml. The active concentration of the compound against HIV is much lower at 100 ng/ml with an inhibition of approximately 90% of the recombinant virus. The therapeutic index of 250 makes it a promising possibility to be studied further for the compound to be used as a drug. The semi-purified extract and the pure compound were tested for its toxicity on VERO cells. The semi-purified extract had no toxicity up to a concentration of 50 _g/ml and the pure compound had toxicity of 20 % up to a concentration of 25_g/ml. The active concentration of 100 ng/ml for the VSV-Pseudotype assay is much lower than the start of toxicity at 25 _g/ml, and leaves a margin of activity before the toxicity level is reached. Both the extract and pure compound shows promising results in vitro to be developed into a medicine to be used against HIV, but need more research on the effects in vivo. Using an extract is easier, cheaper and faster than isolating a pure compound from the extract. It might also be possible that the extract could be prepared as a tea and its use could be very accessible. / Thesis (PhD (Plant Physiology))--University of Pretoria, 2007. / Plant Science / unrestricted
3

Podocarpo, uma planta de interesse ornamental: propagação assexuada

Menegusso, Fernanda Jaqueline 27 February 2018 (has links)
Submitted by Helena Bejio (helena.bejio@unioeste.br) on 2018-06-08T00:45:40Z No. of bitstreams: 2 Fernanda_Menegusso_2018.pdf: 1828109 bytes, checksum: d3740fabed744c8f157c44a448d867b5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-08T00:45:40Z (GMT). No. of bitstreams: 2 Fernanda_Menegusso_2018.pdf: 1828109 bytes, checksum: d3740fabed744c8f157c44a448d867b5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of this study was to evaluate the potential of rooting of podocarpos cuttings in function of the number of leaves, concentrations of IBA and other phytorregulators, different application methods and cutting season. Two experiments were carried out under weaning conditions, in a factorial scheme containing 3 replicates of 15 cuttings, the first with 4 concentrations of IBA (0, 500, 1000 and 1500 mg L-1), 3 numbers of leaves at the cuttings (4, 6, 8) and 2 seasons (winter and summer). These were removed in August/2016 and January/2017, prepared with 10 cm in length and immersed in solutions for 10 s. In the second experiment three types of phytoregulators (IBA, NAA and IAA) and 2 application forms were tested (slow and quick immersion). Cuttings were prepared in the same manner as in the first experiment, maintaining 4 leaves. The bases of the cuttings were immersed for 10 s and 24 h in the solutions, then taken to root in sand bed. After 100 days of experimentation, it was concluded that podocarp cuttings collected in the summer had a higher percentage of rooting, 4 leaves and IBA concentration should be maintained between 750 and 800 mg L-1. The best form of application of phytoregulator is by rapid immersion. / Objetivou-se avaliar o potencial de enraizamento de estacas de podocarpos em função do número de folhas, concentrações de AIB e outros fitorreguladores, diferentes métodos de aplicação e época de estaqueamento. Dois experimentos foram conduzidos em condições de telado, em esquema fatorial contendo 3 repetições de 15 estacas, sendo o primeiro com 4 concentrações de AIB (0, 500, 1000 e 1500 mg L-1), 3 números de folhas na estaca (4, 6, 8) e 2 épocas (inverno e verão). Estas foram retiradas em agosto/2016 e janeiro/2017, preparadas com 10 cm de comprimento e imersas nas soluções por 10 s. No segundo experimento foram testados 3 tipos de fitorreguladores (AIB, ANA e AIA) e 2 formas de aplicação (imersão lenta e rápida). Estacas foram preparadas da mesma maneira que no primeiro experimento, mantendo 4 folhas. As bases das estacas foram mergulhadas por 10 s e 24 h nas soluções, em seguida levadas para enraizar em canteiro de areia. Após 100 dias de experimentação, concluiu-se que estacas de podocarpo coletadas no verão apresentaram maior percentagem de enraizamento, devem ser mantidas 4 folhas e concentração de AIB entre 750 a 800 mg L-1. A melhor forma de aplicação de fitorregulador é por imersão rápida.
4

Isolation and identification of a novel anti-diabetic compound from Euclea undulata thunb

Deutschlander, M.S. (Miranda Susan) 23 October 2010 (has links)
Four plant species traditionally used for the treatment of diabetes by South African traditional healers and herbalists were investigated for hypoglycaemic activity. Species included Schkuhria pinnata (Lam.) Cabrera, Pteronia divaricata (P.J. Bergius) Less Elaeodendron transvaalense (Burtt Davy) R.H. Archer and Euclea undulata Thunb var. myrtina (Burch.) Hiern. Acetone and ethanol plant extracts were prepared and tested in vitro, for glucose utilization, at concentrations of 12.5 µg/ml on three cell lines namely; Murine C2C12 myocytes, Chang liver cells and 3T3-L1 preadipocytes. Metformin, at a concentration of 1 µM (0.166 µg/ml) was used as positive control for hepatic cells and insulin at a concentration 1 µM (5.7 µg/ml) for myocytes and preadipocytes. Toxicity tests were done for all extracts on preadipocytes and hepatic cells, but not on myocytes as these cells were exposed to the extract for only a short period (1 hour) during the hypoglycaemic bioassay. Preadipocytes and hepatic cells were exposed to the plant extracts for 48 hours. The four plant extracts were further investigated for hypoglycaemic activity by evaluating inhibiting effects on carbohydrate-hydrolising enzymes alpha-glycosidase and alpha-amylase. In vitro hypoglycaemic analysis revealed that acetone and ethanol plant extracts of S. pinnata, E. undulata and E. transvaalense, displayed hypoglycaemic activity in one or more of the various cell lines, whereas, P. divaricata showed no hypoglycaemic activity. The best results were obtained with the ethanol and acetone extracts of S. pinnata in preadipocytes with a glucose uptake of 148.2% and 79.6% respectively, above control (100%). However, about 50% preadipocytes survived on exposure to the extracts of S. pinnata at 12.5 µg/ml indicating significant cytotoxicity. Glucose uptake of 63.3% was observed by the ethanol extract of S. pinnata on hepatic cells. E. transvaalense showed hypoglycaemic activity on preadipocytes exhibiting glucose uptake of 38.6% above control 100%. Glucose uptake of 62.2 % were obtained by the E. undulata extract in C2C12 myocytes, with 100% cell viability. E. undulata scored a +3 and was chosen for further analysis. Antidiabetic activity and toxicity of the plant extracts were taken into consideration when scoring was applied. Alpha-glucosidase and alpha-amylase results indicated that P. divaricata extract inhibited alpha-glucosidase (IC50 31.22 µg/ml) whereas E. undulata (IC50 2.80 µg/ml) and E. transvaalense (IC50 1.12 µg/ml) extracts inhibited alpha-amylase. Results obtained indicated that all four plant extracts tested have the ability to lower blood glucose levels to some extent and in different manners and therefore corroborate the ethnomedicinal use of these four species in the treatment of diabetes. Phytochemical studies of a crude acetone extract of the root bark of E. undulata var. myrtina produced a new á-amyrin-3O-β-(5-hydroxy) ferulic acid compound (1), and three known compounds; betulin (2), lupeol (3) and epicatechin (4). The chemical structures were determined by spectroscopic means. In vitro assays on C2C12 myocytes revealed that (2) (21.4%) and (4) (166.3%) were active in lowering blood glucose levels whereas (1) (IC50 4.79 µg/ml) and to a lesser extent (4) (IC50 5.86 µg/ml) and (3) (IC50 6.27 µg/ml) inhibited alpha-glucosidase. These results indicated that the crude, E. undulata acetone extract does contain compounds that display hypoglycaemic activity. The hypoglycaemic activity of four plant species including E. undulata, and the four isolated purified compounds, are reported for the first time. / Thesis (PhD)--University of Pretoria, 2010. / Plant Science / unrestricted
5

RESISTANCE TO THREE COMMON HERBICIDES IN CHAMELEON PLANT (HOUTTUYNIA CORDATA THUNB.), A HIGHLY INVASIVE EXOTIC SPECIES

David James Ice (14231480) 03 February 2023 (has links)
<p> Chameleon plant (<em>Houttuynia cordata</em> Thunb.) is native to Southern and Southeastern Asia. It can reproduce sexually through seeds and asexually through rhizomes and is invasive in multiple countries including the U.S. There has been much research on <em>H. cordata</em> as a medicinal species, and its potential as an invasive species is well documented. However, its herbicidal resistance has not previously been quantified. The objective of this study is to assess <em>H. cordata’s </em>resistance to herbicides. This study consisted of two rounds of tests to examine the resistance of <em>H. cordata</em> plants to three commonly used herbicides: SpeedZone, Weed-B-Gon, and Roundup. Two concentrations of each herbicide were used during each trial in the study: the recommended concentration and twice the recommended concentration. Herbicide treatments were applied outside the greenhouse. Herbicides were sprayed uniformly on the plants until the herbicide was dripping off the leaves. The growth of the treated plants was then monitored in the greenhouse. The herbicides generally reduced growth of the plants temporarily. However, plant extermination was not achieved. Plant samples from all herbicidal treatments regrew from rhizomes after all herbicide treatments. Results from the study showed that <em>H. cordata </em>could not be controlled by the recommended concentrations of herbicides commercially available for horticultural uses in the U.S. Doubling the recommended herbicide concentration was also ineffective in exterminating <em>H. cordata </em>plants. This research clearly showed that <em>H. cordata</em> has the potential to become a highly invasive species with the potential to negatively affect the ecological integrity of many communities in the U.S.</p>
6

Physiological response of the succulent Augea capensis (Zygophyllaceae) of the southern Namib desert to SO2 and drought stress / J.W. Swanepoel

Swanepoel, Jacoba Wilhelmina January 2006 (has links)
The main aim of this study was to investigate the effects of water availability and SO2 pollution, imposed separately or simultaneously, on the photosynthetic metabolism of Augea capensis Thunb., a succulent of the Namib Desert in the region of Skorpion Zinc mine, Namibia. The main driver for this investigation was the need to distinguish between the effects of water availability on plants native to a desert environment, where water availability dominates plant response, but where the possibility of anthropogenic SO2 pollution poses a new threat to the unique succulent vegetation. Fifteen measuring sites were selected in the vicinity of the mine to determine how rainfall influenced the physiological status of the vegetation. Chlorophyll a fluorescence measurements, and analysis of recorded OJlP fluorescence transients with the JIP-test, were used for this purpose. A series of laboratory experiments were also conducted on A. capensis to determine the precise physiological response that water deprivation and SO2 pollution had under controlled growth conditions. Potted plants were exposed to water deprivation or SO2 fumigation in the light or dark. Besides chlorophyll a fluorescence, photosynthetic gas exchange and Rubisco activity were also measured. Changes in fast fluorescence rise kinetics observed under field conditions suggest considerable modulation of photosystem II function by rainfall with concomitant involvement of a heat stress component as well. In both the field and laboratory experiments, one of the JIP-test parameters, the so-called performance index (PIABS), was identified as a very sensitive indicator of the physiological status of the test plants. Moreover, under laboratory conditions, a good correlation existed between the water deprivation-induced decline in CO2 assimilation rates and the decline in PIABS values. The JIP-test in general, and the PIABS in particular, shows considerable potential for application in the investigation of water availability influences on desert ecosystems. In the laboratory experiments, water deprivation caused stomatal closure but also a slight elevation in intercellular C02 concentration and inhibition of Rubisco activity, suggesting that mesophyll limitation was the dominant factor contributing to the decrease in C02 assimilation rates. Following re-watering, A. capensis showed remarkable recovery capacity. Fumigation of A. capensis with 1.2 ppm SO2 in the dark or light revealed relatively small effects on C02 assimilation. The inhibitory effects on photosynthesis were also fully reversible, indicating no permanent metabolic/structural damage. The effects on photosynthesis were more pronounced when fumigation occurred in the dark. This phenomenon might be related to diurnal differences in cellular capacity for SO2 detoxification. When long-term moderate water deprivation was combined with simultaneous SO2 fumigation, there was no additional inhibitory effect on photosynthesis. These findings suggest that water deprivation do not increase sensitivity towards SO2 pollution in A. capensis. Fumigation with SO2, singly or in combination with water deprivation also had no major effect on chloroplast ultrastructure. It appears that A. capensis is remarkably resistant to SO2 pollution even in the presence of low water availability, which is a common phenomenon in desert ecosystems. Since A, capensis seems to be highly tolerant to S02, its suitability as an indicator species for the detection of SO2 pollution effects at Skorpion Zinc mine is questionable. Because water availability dominates the physiological/biochemical response in this species, subtle SO2 pollution effects might be difficult to detect against this dominant background. The high water content of A. capensis and similar succulents might act as a substantial sink for SO2 and could convey considerable tolerance against this form of air pollution. / Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2006.
7

牛樟芝複方飲品抗疲勞功能之評估 / Evaluation of Anti-fatigue Properties of Antrodia Camphorata Drink

劉仁溥, Ren-Pu Liu January 1900 (has links)
牛樟芝 (Antrodia camphorata; AC) 為台灣特有的藥用真菌,是常見的傳統 中藥,富含三萜類化合物及多醣體。本研究使用牛樟芝、葛花、枳椇子與山楂共 四種萃取物製成之牛樟芝複方飲品 (A. camphorate drink, ACD)為原料,評估此一 複方飲品之抗疲勞功效。本研究從運動表現、疲勞生化指標、肌肉損傷生化指數 以及能量儲存等做為抗疲勞評估標準。將 5 週齡雄性 ICR (Institute of Cancer Research) 小鼠,分為三組,每組各 10 隻,分組如下:(1) 對照組 (vehicle, V); (2) 餵食 15.625 mL/kg 牛樟芝複方飲品 (ACD-1X);(3) 餵食 31.25 mL/kg 牛樟芝 複方飲品 (ACD-2X),連續經口餵食 28 天後進行以下試驗: 1. 測試小鼠前肢抓 力、2. 測試 5%負重游泳力竭時間、3. 進行游泳運動 15 分鐘後立即進行採血觀 察乳酸、血氨、血糖及肌酸激酶、4. 小鼠犧牲後,採集肝臟及肌肉組織進行肝醣 分析與切片。結果顯示,ACD-1X 組 (1124 g) 與 ACD-2X 組 (125 6 g) 在前肢 抓力與對照組 (95 6 g) 相比,分別顯著提升 1.19 與 1.32 倍 (p < 0.05)。ACD-1X 組 (56.714.3 min) 與 ACD-2X 組 (60.717.7 min) 在游泳力竭時間與對照組 (18.23.7 min) 比較分別延長 3.12 及 3.34 倍,均有顯著差異 (p < 0.05)。游泳運 動結束後,ACD-1X 組與 ACD-2X 組之乳酸、血氨及肌酸肌酶均顯著低於對照組 (p < 0.05),而血糖方面則顯著高於對照組(p < 0.05)。肌肉肝醣部分,ACD-1X 組 (1.79 ± 0.12 mg/g) 與 ACD-2X 組 (2.36 ± 0.21 mg/g) 相較於對照組 (1.54 ± 0.06 mg/g),2倍牛樟芝複方飲品組顯著提升1.53倍。肝臟肝醣部分,ACD-1X組 (48.9± 4.1 mg/g) 與 ACD-2X 組 (54.1 ± 5.8 mg/g) 與對照組 (27.0 ± 2.4 mg/g) 比較分別 增加 1.18 及 2.00 倍。研究結果顯示,牛樟芝複方飲品具有增加肝臟及肌肉組織 中的肝醣儲存量,且在游泳運動過程中降低血乳酸、血氨及肌酸激酶的產生。進 一步延長負重游泳力竭的時間及前肢抓力表現。因此,本研究證實牛樟芝複方飲 品具有抗疲勞及提升運動表現之功效。 / Antrodia camphorata is an endemic medical mushroom in Taiwan and has been reported to have multi-biological activities such as anti-fatigue, liver protection, anti-cancer, and anti-inflammation. This study was designed to ascertain the ergogenic and anti-fatigue properties of an A. camphorata drink (ACD) (comprising A. camphorata, Pueraria flos flowers, Hovenia dulcis Thunb, and Crataegus pinnatifida) by forelimb grip strength, load-weighted swimming test, and biochemical examinations in mouse model. Thirty male ICR mice (5-week-old) were randomly divided into three groups (n=10 per group): (1) vehicle; (2) a recommended dosage of 15 mg per 75 mL once per day for adult human (ACD-1X); (3) a 2-fold of recommended usage for adult human (ACD-2X). Mice were given orally either vehicle or A. camphorate drink by gavage for 28 days. The groups ACD-1X and ACD-2X showed significant increases in forelimb grip strength, swimming time to exhaustion skeletal, and muscle glycogen as compared to the vehicle group. Blood lactate and ammonia levels in the ACD-1X and ACD-2X groups were significantly lower than in the vehicle group post a swimming test. Moreover, the activity of plasma creatine kinase (CK), a marker of muscular damage, was significantly decreased in the ACD-1X and ACD-2X groups than vehicle group after swimming exercise. These results suggest that A. camphoratahas great potential for application in relevant fields for its ergogenic and anti-fatigue activities. / 第一章 緒論 .........................................................................................................................1 第一節 研究目的..............................................................................................................2 第二章 文獻探討 .................................................................................................................3 第一節 牛樟芝成份及相關研究......................................................................................3 第二節 葛花成份及相關研究..........................................................................................6 第三節 枳椇子成份及相關研究......................................................................................7 第四節 山楂成份及相關研究..........................................................................................8 第五節 運動與疲勞..........................................................................................................9 第三章 材料與方法 ...........................................................................................................12 第一節 實驗測試樣品....................................................................................................12 第二節 實驗動物之飼養與實驗流程............................................................................14 第三節 血液與組織樣本之收集與前處理....................................................................16 第四節 統計分析............................................................................................................17 第四章 結果與討論 ...........................................................................................................18 第一節 補充牛樟芝複方飲品對於小鼠游泳運動能力表現之測試............................18 第二節 補充牛樟芝複方飲品對於小鼠游泳運動後血液中乳酸、血氨、血糖濃 度以及 CK 活性之分析..................................................................................................19 第三節 補充牛樟芝複方飲品對於小鼠前肢抓力表現之測試....................................20 第四節 補充牛樟芝複方飲品對於小鼠肌肉與肝臟部位肝醣含量之分析................21 第五章 結論 .......................................................................................................................22 參考文獻.............................................................................................................31
8

Physiological response of the succulent Augea capensis (Zygophyllaceae) of the southern Namib desert to SO2 and drought stress / J.W. Swanepoel

Swanepoel, Jacoba Wilhelmina January 2006 (has links)
The main aim of this study was to investigate the effects of water availability and SO2 pollution, imposed separately or simultaneously, on the photosynthetic metabolism of Augea capensis Thunb., a succulent of the Namib Desert in the region of Skorpion Zinc mine, Namibia. The main driver for this investigation was the need to distinguish between the effects of water availability on plants native to a desert environment, where water availability dominates plant response, but where the possibility of anthropogenic SO2 pollution poses a new threat to the unique succulent vegetation. Fifteen measuring sites were selected in the vicinity of the mine to determine how rainfall influenced the physiological status of the vegetation. Chlorophyll a fluorescence measurements, and analysis of recorded OJlP fluorescence transients with the JIP-test, were used for this purpose. A series of laboratory experiments were also conducted on A. capensis to determine the precise physiological response that water deprivation and SO2 pollution had under controlled growth conditions. Potted plants were exposed to water deprivation or SO2 fumigation in the light or dark. Besides chlorophyll a fluorescence, photosynthetic gas exchange and Rubisco activity were also measured. Changes in fast fluorescence rise kinetics observed under field conditions suggest considerable modulation of photosystem II function by rainfall with concomitant involvement of a heat stress component as well. In both the field and laboratory experiments, one of the JIP-test parameters, the so-called performance index (PIABS), was identified as a very sensitive indicator of the physiological status of the test plants. Moreover, under laboratory conditions, a good correlation existed between the water deprivation-induced decline in CO2 assimilation rates and the decline in PIABS values. The JIP-test in general, and the PIABS in particular, shows considerable potential for application in the investigation of water availability influences on desert ecosystems. In the laboratory experiments, water deprivation caused stomatal closure but also a slight elevation in intercellular C02 concentration and inhibition of Rubisco activity, suggesting that mesophyll limitation was the dominant factor contributing to the decrease in C02 assimilation rates. Following re-watering, A. capensis showed remarkable recovery capacity. Fumigation of A. capensis with 1.2 ppm SO2 in the dark or light revealed relatively small effects on C02 assimilation. The inhibitory effects on photosynthesis were also fully reversible, indicating no permanent metabolic/structural damage. The effects on photosynthesis were more pronounced when fumigation occurred in the dark. This phenomenon might be related to diurnal differences in cellular capacity for SO2 detoxification. When long-term moderate water deprivation was combined with simultaneous SO2 fumigation, there was no additional inhibitory effect on photosynthesis. These findings suggest that water deprivation do not increase sensitivity towards SO2 pollution in A. capensis. Fumigation with SO2, singly or in combination with water deprivation also had no major effect on chloroplast ultrastructure. It appears that A. capensis is remarkably resistant to SO2 pollution even in the presence of low water availability, which is a common phenomenon in desert ecosystems. Since A, capensis seems to be highly tolerant to S02, its suitability as an indicator species for the detection of SO2 pollution effects at Skorpion Zinc mine is questionable. Because water availability dominates the physiological/biochemical response in this species, subtle SO2 pollution effects might be difficult to detect against this dominant background. The high water content of A. capensis and similar succulents might act as a substantial sink for SO2 and could convey considerable tolerance against this form of air pollution. / Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2006.

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