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The expression of the activin phenotype in the wound healing of diabetic ratsTsai, Chiung-mei 31 July 2005 (has links)
Activin is a dimeric protein of inhibin beta subunit, which is abundantly stored in normal bone matrix, presumably produced by osteoblasts in the process of normal bone formation. The expression of activins was examined in the wound healing of diabetic rats. In this study,insulin-dependent diabetes mellitus was induced in a group of mature Sprague-Dawley rats by injecting streptozotocin. Control animals were injected with citrate buffer only. After 3 weeks,all of rats underwent extraction of the right maxillary molars teeth after anesthesia. Rats were killed at varying intervals and the maxilla and calvaria were recovered in continuity. Tissue sections were stained with hematoxylin-eosin as well as immunohistochemical gent. Hematoxylin-eosin analyses showed that at 7 days after tooth extraction in the control and insulin-streptozotocin-treated rats there were, thick collagen fibers which formed a pretrabecular the scaffold dictated the direction of the forming trabeculae. However,the collagen fibers in the diabetic socket were thin and scanty, and only formed a narrow layer in the apical part of the socket. These histologic observations suggest that in uncontrolled, insulin-dependent diabetes, the formation of the collagenous framework in the tooth extraction socket is inhibited, resulting in delayed healing.The immunohistochemical analyses showed that at 7 days after tooth extraction in both control and insulin-streptozotocin-treated rats, osteoblasts were increased in extra-alveolar bone formation.Our findings also suggested that activin was actively involve in bone modeling during osteogenesis. These findings suggest that activin may play important role in the regulation of bone formation and it may be useful in the future for the wound healing in diabetic patients.
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Interference redukujících látek s hematoxylinovým stanovením chelatace měďnatých iontů / Interference of reducing agents with the hematoxylin assay for determination of cupric chelationZsáková, Emily January 2019 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Emily Zsáková Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of diploma thesis: Interference of reducing agents with the hematoxylin assay for determination of cupric chelation Copper is an essential trace element of living organisms. Disorders of its homeostasis affect various pathological conditions. In excessive amounts, it is toxic due to its ability to form free radicals. Vitamin C, trolox (a water soluble form of vitamin E), glutathione and hydroxylamine possess reducing properties that protect our body from oxidative tissue damage. Oxidized glutathione (GSSG) was also tested for comparison. The object of study was to test the chelating ability of these substances. A simple and fast spectrophotometric method was used. The combination of reducing properties of copper and chelating agents could lead to an improvement in chelation therapy either in heavy metal poisoning, treatment of Wilson's disease, or other diseases. We found that all substances were chelators/copper-chelating agents in vitro in a slightly competitive environment, using hematoxylin as an indicator. However, by using the bathocuproine assays to verify chelating properties, none of the substances...
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Utvärdering av "dumpingmetoden" vid otillräckligt dehydrerade vävnadsprover / Evaluation of the “dumping method” for insufficiently dehydrated tissue samplesMellbo, Johan, Müller, Alisha January 2019 (has links)
När ett vävnadspreparat har genomgått en otillräcklig dehydrering måste det åtgärdas innan provet kan gå vidare i den histotekniska processen. I dagsläget finns det två åtgärdande metoder på Patologilaboratoriet, Region Jönköpings län. Den ena metoden går ut på att provet placeras i smält paraffin för mer stadga. Den andra metoden går ut på att provet rehydreras för att sedan dehydreras på nytt. Syftet med denna studie var att utvärdera en tredje metod, ”dumpingmetoden” som går ut på att vävnadspreparaten dehydreras på nytt direkt utan att först bli rehydrerade. Denna metod utförs i nuläget redan på vissa hud- och obduktionspreparat på Patologilaboratoriet. ”Dumpingmetoden” skulle kunna förenkla arbetet på laboratoriet då den är snabbare, kräver färre kemikalier och är automatiserad till skillnad från befintliga metoder. Resultaten från studien visade att ett otillräckligt dehydrerat vävnadspreparat aldrig kan bli lika bra som om det hade hanterats korrekt från början. Det är dock trots allt möjligt att åtgärda ett otillräckligt dehydrerat preparat i den graden att det blir bedömbart. ”Dumpingmetoden” förenklade snittningen av alla preparat som testades. Hos kolon- och tonsillpreparat verkade ”dumpingmetoden” ge bättre kvalitet av hematoxylin- och eosinfärgningen än de befintliga metoderna. För hudpreparat gav dock metoden där vävnadspreparat rehydrerats för att sedan dehydreras på nytt bäst kvalité av infärgningen. / A tissue that has been insufficiently dehydrated has to be fixed before it can continue through the histotechnological process. Currently, there are two established measures at the Pathology Laboratory, Department of Laboratory Medicine, Region Jönköping County. One of the methods is to put the sample in melted paraffin to give the tissue more support. The other method is to rehydrate the tissue followed by a new dehydration. The purpose of this study was to evaluate a third method called the “dumping method”. The “dumping method” involves a directly dehydration of the tissue, excluding rehydration. This method is currently being used on some of the skin and autopsy samples at the Pathology Laboratory. The “dumping method” would ease the work at the Laboratory since it is faster, requires fewer chemicals and can be automated, unlike the current available methods. The results from the study showed that an insufficiently dehydrated tissue can’t be restore to its original state. Never less it is possible to restore the tissue sufficiently for diagnosis. The “dumping method” eased the sectioning of all the tissue samples included in this study. For colon and tonsil tissues, the “dumping method” ensured higher quality of the haematoxylin and eosin staining than the current available methods. For skin tissues, however, the method of rehydration followed by a new dehydration resulted in the highest staining quality
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Porovnání interakcí ekvolu a desmethylangolensinu se železem a mědí / Comparison of interactions of equol and desmethylangolensin with iron and copperNěmcová, Hana January 2018 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: Hana Němcová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Title of Thesis: Comparison of interactions of equol and desmethylangolensin with iron and copper Iron and copper are essential trace elements, which are important for our body. Both elements have a significant effect on the correct function of organs and make part of many enzymes. They are able to accept or donate electrons - conversion between oxidized (Fe3+, Cu2+) and reduced (Fe2+, Cu+) forms. If these metals are excess in organism, they are accumulated in the cells and mediate the creation of free radicals, that destroy cell structures. This deficiency is treated with chelators, which facilitate the excretion of metals from the body. Isoflavonoids are polyfenolic substances, which can have antioxidant effects and they are involved in the scavening of free radicals. Isoflavonoids can have also a pro-oxidative effect, because they are able to reduce metal ions. In this study were tested interactions (chelation and reduction) between the metabolites of isoflavonoids (equol and desmethylangolensin) and ions of iron and copper. Both metabolites only weakly chelate metal ions, but they significantly reduce cupric ions. KEYWORDS: Iron,...
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Interakce tamarixetinu a isorhamnetinu s mědí / Interactions of tamarixetin and isorhamnetin with copperLomozová, Zuzana January 2019 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: Zuzana Lomozová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Title of Thesis: Interactions of tamarixetin and isorhamnetin with copper Keywords: tamarixetin, isorhamnetin, chelation, reduction, copper, bathocuproine, hematoxylin Copper is a biogenic trace element important for proper function of human organism. It is an essential part of several enzymes and is involved in metabolic processes in the body. Excess or lack of serum copper can lead to pathological conditions. Copper chelating agents are used to treat copper toxic effects. Flavonoids are polyphenolic substances belonging to secondary metabolites of various plants. They are part of the human diet and have a positive impact on our health. They exhibit antioxidant and anti-inflammatory effects and are able to chelate transient metals, especially iron and copper. Chelation therapy is currently used in Wilson's disease in which copper is overloaded. In the future, the chelating effects of flavonoids could be used to treat neurodegenerative diseases, cardiovascular diseases or cancer. In this diploma thesis, interactions of two flavonoids (namely tamarixetin and isorhamnetin) with copper ions in different buffers were tested....
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Interakce fenylpropionových kyselin s mědí / Interaction of phenylpropionic acids with copperZemanová, Kamila January 2017 (has links)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Kamila Zemanová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Title of Thesis: Interaction of phenylpropionic acids with copper Copper is an essential trace element which is essential for our body. It has a significant effect on the correct functioning of important organs and it plays an important role in the transfer of electrons at the major enzymatic pathways as a prostetic group. On the other hand, excess or deficiency of copper in the human body can cause many diseases. Phenylpropionic acids are group of substances which can have antioxidant, anti-inflammatory and anticancer effects. They are involved in the scavenging of free radicals and reactive oxygen species. In this diploma thesis, I tested copper chelating activity of six phenylpropionic acids at different pHs by spectrofotometric methods using a hematoxylin and a bathocuproinedisulfonic acid disodium salt as an indicator. 3-(3,4-dihydroxyphenyl)propionic acid showed the highest chelating potential but only using a hematoxylin. KEYWORDS: Copper, Phenylpropionic acids, Antioxidants, Chelating activity, Hematoxylin, Bathocuproin
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AVALIAÇÃO DA PROLIFERAÇÃO CELULAR E ESPESSURA DO ENDOMÉTRIO DE CADELAS EM DIFERENTES PERÍODOS DO DIESTRO / EVALUATION OF CELL PROLIFERATION AND ENDOMETRIAL THICKNESS OF BITCHES IN DIFFERENT PERIODS OF DIESTRUSGossler, Vanessa da Silva Alves 25 September 2015 (has links)
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Previous issue date: 2015-09-25 / This study aimed to determine the histological features of the endometrium of biches, as well as the cell proliferation at specific moments of diestrus, 10, 20, 30, 40, 50 and 60 days post-ovulation, correlating the endometrial thickness with the uterine cell proliferation and the metabolic state (weight, blood glucose and plasma cholesterol) of the animals. Therefore, the right and left uterine horns of 26 clinically healthy bitches submitted to ovariohysterectomy were histologically analyzed 10, 20, 30, 40, 50 and 60 days post-ovulation. The hematoxylin-eosin and AgNOR staining techniques were performed. All parameters were evaluated by the Shapiro-Wilk normality assumption and the samples subjected to ANOVA and post-hoc Tukey test (p<0.05). The correlation between endometrial thickness and uterine cell proliferation, weight, blood glucose and plasma cholesterol of animals was observed using the Pearson method (p<0.05). The software used was BioEstat® version 5.0. It was concluded that the endometrial thickness did not differs between post-ovulation days and was not correlated with the uterine cell proliferation, weight, blood glucose or serum cholesterol of the bitches. However, there was greater cell proliferation at 40 days post-ovulation compared to 60 days. / O presente estudo teve o objetivo de determinar as características histológicas do endométrio de cadela, assim como a sua proliferação em momentos específicos do diestro nos dias 10, 20, 30, 40, 50 e 60 pós-ovulação, correlacionando a espessura do endométrio com o peso, glicemia e colesterol das cadelas.Para tanto, foram analisados histologicamente os cornos uterinos direito e esquerdo de 26 cadelas clinicamente sadias ovariohisterectomizadas aos 10, 20, 30, 40, 50 e 60 dias após a ovulação. Foram realizadas a coloração de hematoxilina-eosinae também a coloração pelo método de AgNOR. Todos os parâmetros foram avaliados pelo pressuposto de normalidade de Shapiro-Wilk e as amostras submetidas a ANOVA seguida de Tukey (p<0,05). A correlação entre espessura de endométrio e peso, glicemia e colesterol plasmático foi verificada pelo método de Pearson (p<0,05). O programa utilizado foi o BioEstat® versão 5.0. Conclui-se que a espessura do endométrio não difere entre os dias pós-ovulação e que não tem correlação com o peso, glicemia ou o colesterol sérico das cadelas. Porém, há uma maior proliferação celular aos 40 dias pós-ovulação em relação aos 60 dias.
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Utilização da biópsia de mucosa e submucosa retal para o diagnóstico da Moléstia de Hirschsprung / Utilization of mucosal and submucosal rectal biopsy for the diagnosis of Hirschsprung\'s diseaseSuellen Serafini 04 August 2017 (has links)
Introdução: A moléstia de Hirschsprung (MH) se caracteriza pela ausência de neurônios intramurais em segmentos variáveis do intestino grosso, levando a suboclusão intestinal. Na forma mais frequente o reto-sigmoide está comprometido. A biopsia retal é o método histológico de escolha no diagnóstico da MH. O método da hematoxilina e eosina (HE) é classicamente utilizado na prática histopatológica. Nessa técnica, um fragmento de parede total do reto é processado através de parafinização, para posteriormente ser seccionado e corado por HE. Esta coloração evidencia células neurais em intestinos normais e troncos nervosos hipertrofiados nos casos de MH. É uma técnica muito simples, ainda hoje muito utilizada no diagnóstico da doença, necessitando de fragmentos grandes de reto para um maior acerto no diagnóstico. Este detalhe torna o diagnóstico do recém-nascido mais difícil. Outro método de coloração utilizado no diagnóstico da MH é o método histoquímico de pesquisa de atividade de Acetilcolinesterase (AChE). Nesta técnica é necessário apenas um pequeno fragmento de mucosa e submucosa que será congelado e depois processado. A pesquisa de AChE, nos casos de MH mostrará a presença desta enzima em quantidade aumentada, corando troncos e ou fibrilas de cor acastanhado. Este método já vem sendo utilizado pelo Instituto da Criança - HCFMUSP há mais de 30 anos e possui um acerto diagnóstico superior a 90%. Porém, por ser uma técnica mais elaborada, pouquíssimos centros no Brasil a utilizam no diagnóstico da MH. Um outro método mais recente, e que também pode ser realizado em fragmentos menores, é a marcação imunohistoquímica da calretinina, que permite a visualização dos neurônios do plexo submucoso e das fibrilas finas na região da lâmina própria em não doentes. Esta técnica também apresenta maior complexidade e, portanto, não é utilizada. A possibilidade de realizar o diagnóstico da MH através da coloração HE em fragmentos menores poderia ser uma alternativa para os serviços que não dispõe de técnicas mais especificas. Objetivos: Avaliar a concordância dos resultados obtidos pelo método de coloração HE e da calretinina com a pesquisa de atividade de AChE em fragmentos de mucosa e submucosa no diagnóstico da Moléstia de Hirschsprung. Métodos: Para este trabalho foram selecionados 50 casos arquivados em nosso laboratório. O material encontrava-se emblocado em parafina. Foram feitos 60 níveis de cada fragmento para o HE e mais 3 níveis para a calretinina. Essas lâminas foram analisadas em microscópio, fotografadas e classificadas como positivas para MH quando não foram encontradas células neurais e houve a presença de troncos nervosos, e em negativas nos casos de visualização dos neurônios. Foi realizado estudo cego por dois pesquisadores. Os resultados da leitura das lâminas foram comparados com o da AChE. Resultados: Dos 50 casos avaliados pela técnica do HE, apenas 5 discordaram do diagnóstico realizado pela AChE, com um valor de Kappa de 0,800 e acurácia 90%. Na comparação entre a calretinina e a AChE 8 casos discordaram, com um valor de Kappa de 0,676 e acurácia de 84%. Conclusões: A concordância obtida entre os métodos da AChE e HE foi satisfatória. Tornando possível a utilização do método do HE em 60 níveis de fragmento de mucosa e submucosa como alternativa para o diagnóstico da MH. A técnica imunohistoquímica da Calretinina não apresentou a concordância esperada com a pesquisa de atividade de AChE em nosso estudo / Introduction: Hirschsprung disease (HD) is characterized by the absence of intramural neurons in variable segments of the large intestine, leading to intestinal subocclusion. In the most frequent form the rectum-sigmoid is compromised. Rectal biopsy is the histological method of choice in the diagnosis of HD. The hematoxylin and eosin (HE) method is classically used in histopathological practice. In this technique, a full-thickness rectum wall fragment is processed through paraffinization, to be later sectioned and stained by HE. This staining shows neural cells in normal intestines and hypertrophied nerve trunks in cases of HD. It is a very simple technique, still used today in the diagnosis of the disease, requiring large fragments of the rectum for a better diagnosis. This detail makes the diagnosis of the newborn more difficult. The staining histochemical methods more used are the research of acetylcholinesterase activity (AChE) and staining of calretinin. However, these techniques are not available in all centers and the possibility of diagnosing HD through HE staining in smaller fragments could be valuable alternative for services that do not have more specific techniques. Objectives: To evaluate the concordance of the results obtained by the HE staining and the calretinin method with the investigation of AChE activity in fragments of mucosa and submucosa in the diagnosis of Hirschsprung\'s disease. Methods: For this study, 50 cases from our laboratory were selected. The material was embedded in paraffin. Sixty levels of each fragment were made for HE and other 3 levels for calretinin. These slides were analyzed under microscope, photographed and classified as positive for HD when no nerve cells were found and there were nerve trunks present, and in negative in cases of visualization of the neurons. A blind study was carried out by two researchers. The results of reading the slides were compared with that of AChE. Results: Of the 50 cases evaluated by the HE technique, only 5 disagreed with the diagnosis performed by AChE, with a Kappa value of 0.800 and accuracy of 90%. In the comparison between calretinin and AChE, 8 cases disagreed, with a Kappa value of 0.676 and an accuracy of 84%. Conclusions: The concordance of results from AChE and HE methods was satisfactory, allowing the possibility of the use of the HE method in fragments of mucosa and submucosa as valid alternative for the diagnosis of HD. The immunohistochemical technique of Calretinin did not show a good agreement with the AChE activity in our study
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Utilização da biópsia de mucosa e submucosa retal para o diagnóstico da Moléstia de Hirschsprung / Utilization of mucosal and submucosal rectal biopsy for the diagnosis of Hirschsprung\'s diseaseSerafini, Suellen 04 August 2017 (has links)
Introdução: A moléstia de Hirschsprung (MH) se caracteriza pela ausência de neurônios intramurais em segmentos variáveis do intestino grosso, levando a suboclusão intestinal. Na forma mais frequente o reto-sigmoide está comprometido. A biopsia retal é o método histológico de escolha no diagnóstico da MH. O método da hematoxilina e eosina (HE) é classicamente utilizado na prática histopatológica. Nessa técnica, um fragmento de parede total do reto é processado através de parafinização, para posteriormente ser seccionado e corado por HE. Esta coloração evidencia células neurais em intestinos normais e troncos nervosos hipertrofiados nos casos de MH. É uma técnica muito simples, ainda hoje muito utilizada no diagnóstico da doença, necessitando de fragmentos grandes de reto para um maior acerto no diagnóstico. Este detalhe torna o diagnóstico do recém-nascido mais difícil. Outro método de coloração utilizado no diagnóstico da MH é o método histoquímico de pesquisa de atividade de Acetilcolinesterase (AChE). Nesta técnica é necessário apenas um pequeno fragmento de mucosa e submucosa que será congelado e depois processado. A pesquisa de AChE, nos casos de MH mostrará a presença desta enzima em quantidade aumentada, corando troncos e ou fibrilas de cor acastanhado. Este método já vem sendo utilizado pelo Instituto da Criança - HCFMUSP há mais de 30 anos e possui um acerto diagnóstico superior a 90%. Porém, por ser uma técnica mais elaborada, pouquíssimos centros no Brasil a utilizam no diagnóstico da MH. Um outro método mais recente, e que também pode ser realizado em fragmentos menores, é a marcação imunohistoquímica da calretinina, que permite a visualização dos neurônios do plexo submucoso e das fibrilas finas na região da lâmina própria em não doentes. Esta técnica também apresenta maior complexidade e, portanto, não é utilizada. A possibilidade de realizar o diagnóstico da MH através da coloração HE em fragmentos menores poderia ser uma alternativa para os serviços que não dispõe de técnicas mais especificas. Objetivos: Avaliar a concordância dos resultados obtidos pelo método de coloração HE e da calretinina com a pesquisa de atividade de AChE em fragmentos de mucosa e submucosa no diagnóstico da Moléstia de Hirschsprung. Métodos: Para este trabalho foram selecionados 50 casos arquivados em nosso laboratório. O material encontrava-se emblocado em parafina. Foram feitos 60 níveis de cada fragmento para o HE e mais 3 níveis para a calretinina. Essas lâminas foram analisadas em microscópio, fotografadas e classificadas como positivas para MH quando não foram encontradas células neurais e houve a presença de troncos nervosos, e em negativas nos casos de visualização dos neurônios. Foi realizado estudo cego por dois pesquisadores. Os resultados da leitura das lâminas foram comparados com o da AChE. Resultados: Dos 50 casos avaliados pela técnica do HE, apenas 5 discordaram do diagnóstico realizado pela AChE, com um valor de Kappa de 0,800 e acurácia 90%. Na comparação entre a calretinina e a AChE 8 casos discordaram, com um valor de Kappa de 0,676 e acurácia de 84%. Conclusões: A concordância obtida entre os métodos da AChE e HE foi satisfatória. Tornando possível a utilização do método do HE em 60 níveis de fragmento de mucosa e submucosa como alternativa para o diagnóstico da MH. A técnica imunohistoquímica da Calretinina não apresentou a concordância esperada com a pesquisa de atividade de AChE em nosso estudo / Introduction: Hirschsprung disease (HD) is characterized by the absence of intramural neurons in variable segments of the large intestine, leading to intestinal subocclusion. In the most frequent form the rectum-sigmoid is compromised. Rectal biopsy is the histological method of choice in the diagnosis of HD. The hematoxylin and eosin (HE) method is classically used in histopathological practice. In this technique, a full-thickness rectum wall fragment is processed through paraffinization, to be later sectioned and stained by HE. This staining shows neural cells in normal intestines and hypertrophied nerve trunks in cases of HD. It is a very simple technique, still used today in the diagnosis of the disease, requiring large fragments of the rectum for a better diagnosis. This detail makes the diagnosis of the newborn more difficult. The staining histochemical methods more used are the research of acetylcholinesterase activity (AChE) and staining of calretinin. However, these techniques are not available in all centers and the possibility of diagnosing HD through HE staining in smaller fragments could be valuable alternative for services that do not have more specific techniques. Objectives: To evaluate the concordance of the results obtained by the HE staining and the calretinin method with the investigation of AChE activity in fragments of mucosa and submucosa in the diagnosis of Hirschsprung\'s disease. Methods: For this study, 50 cases from our laboratory were selected. The material was embedded in paraffin. Sixty levels of each fragment were made for HE and other 3 levels for calretinin. These slides were analyzed under microscope, photographed and classified as positive for HD when no nerve cells were found and there were nerve trunks present, and in negative in cases of visualization of the neurons. A blind study was carried out by two researchers. The results of reading the slides were compared with that of AChE. Results: Of the 50 cases evaluated by the HE technique, only 5 disagreed with the diagnosis performed by AChE, with a Kappa value of 0.800 and accuracy of 90%. In the comparison between calretinin and AChE, 8 cases disagreed, with a Kappa value of 0.676 and an accuracy of 84%. Conclusions: The concordance of results from AChE and HE methods was satisfactory, allowing the possibility of the use of the HE method in fragments of mucosa and submucosa as valid alternative for the diagnosis of HD. The immunohistochemical technique of Calretinin did not show a good agreement with the AChE activity in our study
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Responses of accessions of Austrodanthonia spp. to factors associated with soil acidityIslam, Mohammed Anowarul January 2003 (has links)
Pasture plants already adapted to acidic soil conditions are required as part of an integrated approach (with lime amelioration) to managing acid soils on the Tablelands of New South Wales, Australia. The objective of this thesis is to evaluate the usefulness of Austrodanthonia species for this purpose. The material evaluated in this study was collected during a previous survey of the distribution of Austrodanthonia on the Central, Southern and Monaro Tablelands of New South Wales. It was hypothesised that the genus Austrodanthonia has a wide range of tolerance to acid soils. A series of experiments that provided information on the growth and physiology of Austrodanthonia in relation to soil acidity, with a view to the identification and eventual domestication of the most promising plant material have been conducted through pot, hydroponics and field investigations. Firstly, soils were acidified or limed to obtain a range of soil pH and Al concentrations. This experiment showed that adding aluminium sulfate and calcium carbonate followed by washing excess salts with water is a simple, rapid and convenient method for adjusting soil pH for pot experiments. The pH of the amended soils remained relatively unchanged eight months after treatment. The experimental set-up also resulted in a wide range of soluble Al (2-52 mg/kg) across the soils. The relative Al-tolerance of 183 accessions from 15 Austrodanthonia species was tested in a pot experiment using a range of soil pH. Emergence, survival and growth of all accessions were drastically reduced by high soil acidity (pH 3.9, P < 0.001). About 11% of plants emerged at pH 3.9, whereas at pH 4.4 and 5.3, ~72% of plants emerged. Accessions exhibited large variation within and between species in their tolerance to soil acidity. From the species/accessions tested, 49 accessions from eight species were selected for further study (on the basis of being more acid tolerant). Hydroponic experiments conducted in the glasshouse evaluated: (i) formulation of nutrient solution with a stable pH, (ii) effectiveness of the formulation using tap water and deionised water and (iii) estimation of free ion activities of Al and Mn in the nutrient solution and their effects on Austrodanthonia growth. These experiments showed that a NO3-N/NH4-N ratio of 9:4 is the most appropriate ratio to obtain a stable pH 4.0 without affecting plant growth; that there was little difference between tap water and deionised water on the ionic effects of Al and Mn, and plant-size did not play a role on accession survival and that accessions of Austrodanthonia could grow well within a wide range of pH (3.5-5.5), Al (50-250 �M) and Mn (100-2000 �M). Growth of Austrodanthonia accessions declined under high acidity (pH < 3.5) and Al (300 �M), but tolerated high concentrations of Mn (2000 �M). Root-tips stained with hematoxylin grouped accessions in a similar way to the pot and hydroponic experiments for most of the accessions tested. The intensity of root staining with hematoxylin and the differential distribution of Al in the shoots and roots provided an indication that different tolerance mechanisms may be involved with Austrodanthonia accessions. It appears that both exclusion and internal mechanisms may operate for Al- and Mn-tolerance. A field experiment was conducted at Carcoar (33037�S, 149013�E, elevation 800 m) using gradients in soil pH and Al available on-site to grow selected accessions of Austrodanthonia. The accessions exhibited a range of responses to soil acidity. The accession responses to acidity from the pot and hydroponic experiments were similar to those obtained in the field, especially where Al was present as a low Al-challenge. Overall, this study shows that Austrodanthonia exhibits a wide range of acid tolerance between species and accessions within species. Among the species tested, A. duttoniana and A. fulva appeared to have the greatest commercial potential, because of their productivity and acid tolerance. The variability that exists in the accessions may be exploitable in breeding and selection programs for improved cultivars.
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