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Aspectos fisiológicos, bioquímicos e microbiológicos em beterrabas minimamente processadas. / Physiological, biochemichal and microbiological aspects of fresh-cut beet roots.Maria Carolina Dário Vitti 29 May 2003 (has links)
Os objetivos deste trabalho foram determinar respostas fisiológicas, bioquímicas e microbiológicas associadas ao processamento mínimo de beterraba e desenvolver um fluxograma de preparo específico para está hortaliça, visando menor perda de qualidade e máxima capacidade de conservação. No primeiro experimento foram estudados alguns aspectos fisiológicos de beterraba intactas, descascadas e raladas e aspectos microbiológicos de beterrabas raladas. Neste experimento foram realizadas análises da taxa respiratória, da produção de etileno e microbiológicas. No segundo experimento foi testado o efeito do ácido cítrico sobre a respiração e pigmentos de betalaínas, determinando-se a taxa respiratória e os teores de betalaínas. No terceiro experimento avaliou-se o tempo de sanitização para beterrabas minimamente processadas, sendo realizadas análises sensoriais, microbiológicas e físico-químicas. No quarto experimento foi estudado o momento de sanitização ideal para beterrabas minimamente processadas, sendo também efetuadas análises sensorias, microbiológicas e físico-químicas. E no quinto experimento foi testado o novo fluxograma de preparo, específico para beterrabas minimamente processadas através de métodos combinados, obtidos a partir de resultados dos testes anteriores. Análises sensoriais, microbiológicas e físico-químicas foram realizadas para avaliar o novo fluxograma. A taxa respiratória foi maior para beterrabas raladas. A produção de etileno somente foi detectada em beterrabas raladas. Os resultados das análises microbiológicas estão de acordo com o padrão vigente atualmente. O ácido cítrico reduziu a atividade respiratória e o extravazamento e a degradação dos pigmentos de betalaínas em beterrabas minimamente processadas. O tempo de sanitização de 3 minutos é mais apropridado para manutenção da qualidade. A sanitização apenas após a pelagem é a mais apropriada para manutenção da qualidade, pois reduz a perda de pigmentos e garante um produto com padrões microbiológicos abaixo dos limites permitidos pela Legislação Brasileira, além de evitar o desperdício de cloro. Verificou-se pelo novo fluxograma de preparo que as beterrabas minimamente processadas tem um período de comercialização viável por 10 dias. O novo fluxograma desenvolvido é mais indicado para manutenção da qualidade por reduzir perda de pigmentos, reduzir a taxa respiratória e garantir a segurança alimentar do produto. / The purposes of this work were to determine the physiological, biochemical and microbiological responses to minimal processing of beet roots and to develop a preparation flowchart for this vegetable, aiming at lowering quality losses and maximizing preservation. Some physiological aspects of whole, peeled and grated beet roots, as well as microbiological aspects of grated beet roots were studied in the first experiment. Analyses of respiratory rate, ethylene production and microbiology were carried out in this experiment. In the second experiment, respiratory rates and betalain amounts were determined to evaluate the effects of citric acid on respiration and betalain pigments. In a third experiment, the sanitization time for minimally processed beet roots was evaluated and sensory, microbiological and physicochemical analyses were carried out. In a fourth experiment, the ideal sanitization time for minimally processed beet roots was determined and sensory, microbiological and physicochemical analyses were carried out. In a fifth experiment, a specific new procedures flowchart was tested for the minimal processing of beet roots using a combination of methods based on previous experiments. Sensory, microbiological and physicochemical analyses were conducted to evaluate the new procedures flowchart. The respiratory rate was higher in grated beet root. Ethylene production was detected only in grated beet roots. The microbiological results were in accordance with the current standard. Citric acid reduced the respiratory activity, betalain exudation and degradation in minimally processed beet roots. A three-minute sanitization showed to be the most suitable for quality maintenance. Sanitization alone after pealing is appropriate for quality maintenance, as it decreases pigment losses, prevents wasteful use of chlorine and ensures microbiological standards to be in accordance with the Brazilian Legislation. Minimally processed beet root produced by the new procedures flowchart are suitable for commercialization for 10 days. The new procedures flowchart is especially recommended for quality maintenance, once it decreases pigment loss and the respiratory rate, and ensures good food-safety standards for the product.
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Caracterização do efeito tóxico de extrato de culturas líquidas de Leifsonia xyli subsp. xyli na germinação de sementes de alface / Biological characterization of the toxic effects of extracts of liquid cultures of Leifsonia xyli subsp. xyli on the germination of lettuce seedsFernanda Raquel Oliveira de Souza Rezende de Castro 31 May 2012 (has links)
Este estudo avaliou os efeitos de extratos de culturas líquidas de Leifsonia xyli subsp. xyli (Lxx) cultivada sob condições de estresse osmótico e na presença de inibidores da rota não-mevalonato (MEP/DOXP) de síntese de pigmentos isoprenóides, na germinação de sementes de alface. Também avaliou a relação entre o efeito tóxico dos extratos e a produção de pigmentos pela bactéria. Os extratos foram obtidos do sobrenadante de culturas de Lxx usando acetato de etila como solvente. Ensaios com sementes de alface embebidas nos extratos indicaram uma ação inibitória na germinação das sementes e no alongamento das radículas quando a bactéria foi cultivada na presença de 7% de PEG 6000 ou 100 mM de NaCl. O extrato foi submetido a vários tratamentos térmicos (temperatura ambiente; 30, 60 e 90oC em banho-maria e 121oC por autoclavagem) e sua ação inibitória em sementes mostrou-se termoestável. A presença de pigmentos isoprenóides de células cultivadas com PEG ou NaCl e de células incubadas sem estes agentes estressantes foi avaliada por espectrofotometria após extração dos pigmentos com metanol. Em células cultivadas na ausência de estresse, notou-se um pico de absorbância bem definido no comprimento de onda de 400 nm, ao passo que este pico foi sensivelmente reduzido em células cultivadas sob estresse. Esse efeito foi mais pronunciado na presença de PEG. Para confirmar a natureza isoprenóide do composto, Lxx foi cultivada na presença de fosmidomicina ou difenilamina, que são inibidores da rota metabólica não-mevalonato destes compostos em Microbacteriaceae. Ambas as substâncias reduziram o pico de absorbância no espectro em relação a células cultivadas sem adição destes antibióticos, confirmando a natureza do composto e sua via de síntese. No entanto, a redução foi mais acentuada no caso da fosmidomicina. Por fim, a fosmidomicina foi utilizada com a finalidade de verificar seu efeito na toxidez dos extratos. Foi observado que o efeito tóxico do extrato foi reduzido quando Lxx foi cultivada na presença do inibidor. Ao se avaliar o conteúdo das células, notou-se também redução expressiva no conteúdo relativo de compostos isoprenóides, como esperado. Os resultados indicaram que a bactéria secreta um produto cuja ação é similar à do ABA e que há uma correlação entre a produção do mesmo e a síntese de pigmentos isoprenóides. Em conjunto, o estudo dá suporte à hipótese levantada anteriormente por Monteiro- Vitorello et al. (2004) com base em análise in silico do genoma de Lxx, segundo a qual a bactéria estaria apta a secretar um composto análogo ao ácido abscísico (ABA). / This study evaluated the effects of extracts of liquid cultures of Leifsonia xyli subsp. xyli (Lxx) grown under osmotic stress and in the presence of inhibitors of the non-mevalonate pathway (MEP/DOXP) of synthesis of isoprenoid pigments on the germination of lettuce seeds. The relationship between the extracts toxic effect and the production of pigments was evaluated as well. The extracts were obtained from the supernatant of Lxx cultures using ethyl acetate as a solvent. Essays with lettuce seeds soaked in the extracts indicated an inhibitory action on germination and on the elongation of the radicles when the bacterium was cultivated in the presence of 7% PEG 6000 or 100 mM NaCl. The extract was submitted to different thermal treatments (room temperature; 30, 60 and 90oC water bath and 121oC autoclaving) and its inhibitory action was shown to be thermostable. The presence of isoprenoid pigments in cells cultivated with PEG, NaCl or in the absence of these stressing agents was evaluated by spectrophotometry after extracting the pigments with methanol. In cells incubated in the absence of stress, a well-defined absorbance peak at 400 nm wavelength was noted, whereas this peak was sensibly reduced in cells cultivated under stress. This effect was more pronounced in the presence of PEG. To confirm the isoprenoid nature of the compound, Lxx was incubated in the presence of fosmidomycin and diphenylamine, which are inhibitors of the nonmevalonate metabolic pathway of these compounds in Microbacteriaceae. Both substances reduced the absorbance peak in the spectrum compared to cells cultivated in the absence of these antibiotics, confirming the nature of the compound and its synthesis pathway. Moreover, the peak reduction was more accentuated in the presence of fosmidomycin. Lastly, fosmidomycin was used to evaluate its effect on the toxicity of the extracts. It was observed that the toxic effect of the extract was reduced when Lxx was cultivated in the presence of this inhibitor. When the cell content was evaluated, an expressive reduction on the relative content of carotenoid compounds has also been noticed, as expected. The results indicated that the bacterium secretes a compound whose action is similar to ABA and that there is a correlation between the production of this compound and the synthesis of isoprenoid pigments. The results support the hypothesis proposed earlier by Monteiro-Vitorello et al. (2004) based upon an in silico analysis of the genome of Lxx, according to which the bacterium would be able to secrete a compound analogous to abscisic acid (ABA)
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Espectroscopia Raman aplicada ao estudo de pigmentos em bens culturais: I - pinturas rupestres / Raman spectroscopy applied to the study of pigments in cultural goods: I - rupestrian paintingsFrancisco Nascimento Lopes 14 March 2005 (has links)
Neste estudo amostras coletadas de pinturas rupestres foram analisadas para identificação do material utilizado; análises da sua interação e de processos eventuais de degradação, além de atribuições quanto à sua origem, foram também feitas através da espectroscopia Raman. Pigmentos encontrados em pinturas rupestres em Minas Gerais foram identificados, junto a produtos de degradação microbiológica. A partir dos resultados, foi feita uma caracterização da transformação de desidratação do pigmento amarelo de goetita (α-FeOOH) a hematita (α-Fe2O3) por espectroscopia Raman na tentativa de contextualizá-la no problema da origem da hematita encontrada nas representações. Foram identificados os pigmentos calcita (CaCO3) para o branco, carvão vegetal para o preto, goetita (α-FeOOH) para o amarelo e hematita (α-Fe2O3) para o vermelho, que constituem basicamente a paleta de cores desse período. Produtos de degradação microbiológica foram identificados por espectroscopia Raman e no infravermelho por ATR como sendo whewellita (CaC2O4.H2O) e weddelita(CaC2O4.2H2O). A transformação topotática de goetita a hematita por aquecimento foi acompanhada por espectroscopia Raman in situ e ex-situ e infravermelho, na tentativa de caracterizar o processo quanto às fases formadas, possíveis marcadores, de maneira a complementar resultados da literatura que utilizaram outras técnicas, como difração de raio-X (XRD) e microscopia eletrônica de transmissão (TEM). Esse estudo foi realizado na tentativa de determinar a existência de possível manipulação térmica desses materiais como sugerido em trabalhos anteriores. Em particular, nos espectros Raman, o comportamento diferenciado da banda em torno de 660 cm-1 e a maior largura das bandas de uma maneira geral, presentes na chamada hematita desordenada, perfil que as amostras naturais coletadas apresentam, são marcadores do efeito de temperatura, uma vez que parecem estar ligados mais estreitamente ao deslocamento catiônico dos íons Fe do que ao rearranjo da gaiola octaédrica de oxigênios ao redor destes, durante a transição a partir de goetita. Esse comportamento dos espectros Raman é confirmado pelos padrões dos difratogramas de raio-X. Concluiu-se que esse desordenamento, entretanto, não é causado somente pela temperatura e, dessa forma, não pode ser usado para atestar inequivocamente como sendo resultado de processamento dos materiais (goetita). / This dissertation reports the investigation carried out on samples collected from rupestrian paintings, aiming at the identification of materials used, their interaction and degradation. The technique of choice was Raman microscopy as it is a non-destructive tool, which provides the spatial resolution necessary for the study of heterogeneous samples. Pigments were identified together with products of microbiological degradation. Thermal convertion of goethite (yellow) to hematite (red) was followed by Raman spectroscopy in a tentative to address the issue of the provenance of red pigments (natural hematite or heated goethite) found in the paintings. White pigments were identified as calcite (CaCO3), whereas charcoal was used as black, goethite (α-FeOOH) as yellow and hematite (α-Fe2O3) as red. These pigments are usually found in rock art palletes. Degradation products from microbiological activity were identified by Raman microscopy and ATR infrared spectroscopy as being whewellite (CaC2O4.H2O) and weddelite (CaC2O4.2H2O). The topotatic transition from goethite to hematite was followed by in situ and ex-situ Raman and infrared spectroscopy, regarding the characterization of the phases formed, possible markers, aiming to complement the previous results reported in the literature using other techniques such as X-ray diffractometry (XRD) and transmission eletron microscopy (TEM). The main goal of the study of temperature effect on the Raman spectrum of goethite was to determine whether hematite was used as found in nature or was obtained by goethite heating as suggested in previous investigations. Particularly, the behavior of the 660 cm-1 band and a larger linewidth for bands in the spectrum, present in the disordered hematite and in the red pigments analysed, are markers of the thermal processing. These features seem to be related to the movement of iron ions and to the rearrangment of the octahedrical cage formed by oxygen atoms around them. Such conclusions are in agreement with X-ray data. Unfortunately, temperature is not the only factor to cause such structural disorder and, hence, it cannot be used as an unequivocal marker of thermal processing.
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Efeitos da irradiância sobre a fotossíntese, crescimento e produção de óleo essencial em poliplóides de Lippa alba (mill.) N.e.Brown (Verbenaceae)Pacheco, Vinícius Sacramento 04 August 2017 (has links)
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Previous issue date: 2017-08-04 / Lippia alba (Mill.) N.E. Brown (Verbenaceae) é uma das espécies medicinais mais amplamente utilizadas no Brasil. Nas últimas décadas, grande número de trabalhos vem investigando e comprovando os efeitos farmacológicos dos componentes encontradas no óleo essencial dessa planta. Estudos relacionados à genômica demonstram a ocorrência de poliploidia natural na espécie, condição que pode interferir na composição e produção dessas substâncias. Em contrapartida, fatores ambientais, como a irradiância e disponibilidade hídrica, também são importantes modeladores da biossíntese dessas moléculas, podendo interagir com o fator genético. Diante do exposto, investigou-se os efeitos de níveis contrastantes de irradiância, a 100% (pleno sol) e 30%( à sombra), durante as épocas seca e chuvosa de cultivo, sobre as trocas gasosas e seus posteriores efeitos sobre o crescimento e a produção de óleo essencial em acessos de L. alba que possuíam três níveis de ploidia distintos (Di-; Tetra- e Hexaploide). Para a maioria dos parâmetros de trocas gasosas, as plantas cultivadas à sombra apresentaram valores menores quando comparados às plantas cultivadas a pleno sol, independentemente da época de cultivo. Em ambos os níveis de irradiância, o acesso tetraploide apresentou os menores valores para a fotossíntese liquida, bruta, fotorrespiração, condutância estomática e taxa de transporte de elétrons para carboxilação e oxigenação. Acessos cultivados à sombra apresentaram respostas tipicamente associadas a essa condição de luminosidade, com maior área foliar especifica e unitária, alocação preferencial de biomassa em parte aérea e maior conteúdo de clorofilas, bem como valores menores em biomassa de raiz, massa total e taxa assimilatória liquida. Em comparação aos cultivados a pleno sol, todos os acessos cultivados à sombra apresentaram conteúdo de óleo essencial , em média, 40% menor. Quando cultivados a pleno sol o acesso diploide apresentou o maior conteúdo de óleo essencial, que foi em média 150% maior, que o observados para os acessos tetra- e hexaploide. À sombra, o conteúdo de óleo essencial do acesso diploide foi 120% maior que os demais. Entretanto, nessa condição, este acesso apresentou a menor biomassa total. Os resultados encontrados permitem concluir que o acesso diploide, independentemente da irradiância em que foi cultivado, apresento o maior rendimento da produção de óleo essencial, sugerindo maior atividade das vias do metabolismo secundário, reduzindo o acúmulo de biomassa sob baixa irradiância. / Lippia alba (Mill.) N.E. Brown (Verbenaceae) is one of the most widely used medicinal species in Brazil. In the last decades, a great number of works have been investigating and proving the pharmacological effects of the components found in the essential oil of this plant. Studies related to genomics demonstrate the occurrence of natural polyploidy in the species, a condition that may interfere in the composition and production of these substances. In contrast, environmental factors, such as irradiance and water availability, are also important modellers of the biosynthesis of these molecules, and may interact with the genetic factor. Considering the above, the effects of contrasting levels of irradiance, at 100% (full sun) and 30% (in the shade), during the dry and rainy seasons of cultivation, on the gas exchanges and their subsequent effects on growth were investigated and the production of essential oil in L. alba accesses that had three distinct levels of ploidy (Di-, Tetra- and Hexaploid). For most gaseous exchange parameters, shade-grown plants presented lower values when compared to plants grown in full sun, regardless of the growing season. In both levels of irradiance, tetraploid access presented the lowest values for liquid photosynthesis, crude, photorespiration, stomatal conductance and electron transport rate for carboxylation and oxygenation. Shade - grown accesses presented responses typically associated to this luminosity condition, with a greater specific and unitary leaf area, preferential allocation of biomass in aerial part and higher content of chlorophylls, as well as lower values in root biomass, total mass and net assimilation rate. Compared to those grown in the full sun, all accesses cultivated in the shade had an essential oil content, on average, 40% lower. When cultivated in full sun the diploid access had the highest essential oil content, which was on average 150% higher than that observed for the tetra- and hexaploid accessions. In the shade, the essential oil content of the diploid access was 120% greater than others accessions. However, in this condition, this access presented the lowest total biomass. The results show that diploid access, irrespective of the irradiance in which it was cultivated, presents the highest yield of essential oil production, suggesting higher activity of the secondary metabolism pathways, reducing the accumulation of biomass under low irradiance.
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Alterações fisiológicas em milho cultivado em solo com alto teor de cobre e submetido à aplicação de zinco / Physiological amendments in corn grown in soil with high content of copper and submitted to zinc applicationTiecher, Tadeu Luis 07 February 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Due to the historical application of cupric fungicides in vineyards, the amounts of copper (Cu) in these soils can reach levels that cause toxicity to plants. Recently researchers have tried alternative products to the cupric ones, in order to reduce the amount of Cu applied to the vineyards, which usually shows zinc (Zn) in its composition. This study aimed to evaluate the biochemical and physiological changes in corn plants, grown in soil with a high content of Cu and different levels added of Zn. In November 2011 the soil was collected from the 0-15 cm layer of a vineyard with high Cu content and in an area of native grass adjacent to the vineyard, with low concentrations of Cu and Zn, which served as treatment control, and both soils were classified as Typic Hapludalf. The experiment was performed in a greenhouse and was divided into two corn crops, the first between March and April, and the second between October and November, both in 2012. The treatments were the doses of 0, 30, 60, 90, 180 and 270 mg kg-1 of Zn added to the soil of the vineyard, plus the control treatment. Treatments had pH values in water and levels of available phosphorus and exchangeable potassium similar. At 35 days after emergence the plants were harvested and the accumulation of dry matter from roots and shoots and the concentration of Cu and Zn in leaves were determined. It was also evaluated the operation of the photosynthetic apparatus from the fluorescence of chlorophyll a and the photosynthetic pigments, biochemical parameters related to oxidative stress in leaves of plants, such as activity of superoxide dismutase (SOD) and of non-specific peroxidase (POD) were evaluated. The high concentrations of Cu and Zn in soil caused toxicity to corn plants and provided foliar concentrations above the levels considered normal in the leaves, from both cultivations. The Zn toxicity was evidenced by the decrease in the growth of both roots and shoots, as well as the induction of symptoms of toxicity and deficiency in photosynthetic parameters, reflecting photoinhibition. Moreover, it was observed oxidative stress and the antioxidant system of maize plants was not effective enough to reverse the condition of stress, especially in cultivated soils received higher doses of Zn. / Devido ao histórico de aplicação de fungicidas cúpricos em vinhedos, os teores de cobre (Cu) nestes solos podem atingir níveis que causam toxicidade às plantas. Recentemente tem-se buscado produtos alternativos aos cúpricos, com o intuito de reduzir a quantidade de Cu aportado aos vinhedos, os quais geralmente apresentam zinco (Zn) em sua composição. O objetivo foi avaliar se o aumento na concentração de Zn no solo poderia significar toxidez adicional às plantas de milho cultivadas, em um ambiente já contaminado com alto teor de Cu no solo. Em novembro de 2011 o solo foi coletado na camada de 0-15 cm de um vinhedo com alto teor de Cu e em uma área de campo nativo adjacente ao vinhedo, com baixos teores de Cu e Zn, o qual serviu como tratamento controle, sendo que ambos os solos foram classificados como Argissolo Vermelho. O experimento foi conduzido em casa de vegetação e foi dividido em dois cultivos de milho. O primeiro entre março e abril, e o segundo entre outubro e novembro, ambos no ano de 2012. Os tratamentos foram as doses de 0, 30, 60, 90, 180 e 270 mg kg-1 de Zn adicionadas ao solo de vinhedo, mais o tratamento controle, todos com valores de pH em água e teores de fósforo disponível e potássio trocável semelhantes. Aos 35 dias após a emergência as plantas foram coletadas e o acúmulo de matéria seca de raízes, de parte aérea e a concentração de Cu e Zn nas folhas foram determinados. Foi avaliado também o funcionamento do aparato fotossintético a partir da fluorescência da clorofila a e os pigmentos fotossintéticos, parâmetros bioquímicos ligados ao estresse oxidativo nas folhas das plantas, tais como atividade das enzimas superóxido dismutase (SOD) e das peroxidases não específicas (POD). Os teores elevados de Cu e Zn no solo causaram toxicidade às plantas de milho e proporcionaram teores foliares acima dos níveis considerados normais nas folhas das plantas, nos dois cultivos. A toxicidade de Zn se evidenciou através da diminuição no crescimento, tanto das raízes, como da parte aérea, bem como pela indução de sintomas de toxicidade e deficiência nos parâmetros fotossintéticos, refletindo na fotoinibição. Além disso, foi observado estresse oxidativo e o sistema antioxidante das plantas de milho não foi suficientemente eficaz para reverter a condição de estresse, especialmente nas plantas cultivadas nos solos que receberam as maiores doses de Zn.
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TECNOLOGIA DE SEMENTES E PARÂMETROS MORFOFISIOLÓGICOS NA PROPAGAÇÃO DE Tabernaemontana catharinensis A. DC. (APOCYNACEAE) / SEED TECHNOLOGY AND MORPHOPHYSIOLOGICAL PARAMETERS IN THE PROPAGATION OF Tabernaemontana catharinensis A. DC. (APOCYNACEAE)Afonso, Marcelo Vielmo 03 March 2016 (has links)
Tabernaemontana catharinensis, popularly known as cobrina, is a native tree, which
belongs to the family Apocynaceae. This species is suitable for reforestation, it is rich
in phytochemicals compounds and it is used in folk medicine in the form of tea or
infusion of its leaves and barks. Impacts of the indiscriminate extraction of seeds and
vegetative parts of native species have increased in recent years, being the
cultivation of plants on a large scale in a sustainable manner one of the challenges
for production - without compromising natural resources. However many species still
lack ecological, physiological and agronomic information. Then, the aims of this study
were to evaluate the physiological quality of seeds and morphophysiological
parameters of T. catharinensis propagated in vitro and ex vitro. In this regard, ripe
fruits were collected in mid lateral third of five arrays with approximately four meters
high and located in the remaining vegetation in the city of Ijuí, Northwest region of
Rio Grande do Sul (28° 26' 07 "S and 53° 57' 50"W). The experiments were
performed in laboratory and in greenhouse. In the laboratory, seeds were germinated
in the presence of light (photoperiod of 16 hours) and in the absence of light
(continuous dark), by testing five temperatures: 15, 20, 25, 30 °C and alternating 20
to 30 °C (night-day). Three conditions and storage temperatures: 25 ± 1 °C (growth
room), 10 ± 1 °C (refrigerator) and 4 ± 1 °C (cold room), were part of the experiment.
They were used to check the germination behavior and the water content during six
periods seed storage (30, 60, 90, 120, 150 and 180 days). We observed that,
regardless of photoperiod (photoperiod of 16 hours and continuous darkness), 25
and 30 °C temperatures promoted the highest percentage of germination of T.
catharinensis seeds. T. catharinensis seeds behave as neutral photoblastic. The
storage of seeds of T. catharinensis for 180 days reduces the water content of the
seeds, not occurring the reduction in germination potential, which demonstrates an
orthodox behavior. For the experiments in vitro conditions, in order to obtain
seedlings and the establishment of T. catharinensis, seeds were pre-soaked in
gibberellic acid (GA3) at concentrations of 0.0; 300 and 600 mg L-1 in two regimes of
time 24 and 48 hours. Afterwards, the cotyledon segments of 1 cm seedlings
obtained in vitro germination. With 70 days old, they were inoculated in culture
medium with 100% of minerals MS (MURASHIGE; SKOOG, 1962), plus
combinations of 6-benzylaminopurine (BAP) 0.0; 1.0; 2.0; 4.0; 6.0 mg L-1 and
naphthaleneacetic acid (NAA) 0.0; 0.1; 0.2; 0.4; 0.6 mg L-1. For in vitro rooting
experiment, microcuttings of 90 days, with three pairs of leaves, were inoculated in
MS medium (MURASHIGE; SKOOG, 1962), supplemented with IBA concentrations
0.0; 1.0; 2.0; 4.0; 6.0 mg L1. The percentage of germination was not significantly
different in pre-soaked seeds in GA3, however we observed a reduction in the speed
of germination at concentrations of 300 and 600 mg L-1 of GA3 for 48h of immersion.
In vitro establishment, we verified the direct organogenesis of adventitious shoots
from cotyledons of cobrina without the need for growth regulator, but the use of BAP
associated with NAA maximized the number of shoots, leaves and fresh mass of
shoots. For the in vitro experiment rooting supplementation of 1.0 and 6.0 mg L-1 of
IBA to the culture medium resulted in the highest rooting rate (96.5 and 89%,
respectively) and root length (15.96 and 15.60 cm, respectively). The absence of
growth regulators (IBA) decreased the number of tips and root volume and the
contents of chlorophyll b. For the experiment in the greenhouse, the treatments were
Mecplant® substrate compositions (commercial substrate), fine texture vermiculite (V)
and carbonized rice husk (CRH), by evaluating their influence on the emergence,
vigor and morphophysiological parameters of T. catharinensis. We found out that the
isolated use of commercial substrate 100% Mecplant® occurred less emergency and
IVG seedlings, which negatively affected the growth characteristics. The commercial
substrate associated with inert material vermiculite in formulations 50% Mecplant® +
50% V and 25% Mecplant® + 75% V showed higher expression of seed vigor and
greater seedling growth, proving to be more appropriate, from the study to the
formation of cobrina seedlings. Levels of chlorophyll b, as well as the total carotenoid
are not influenced by the substrates. The ratio of chlorophyll a/b is higher in the
treatments T2 (75% Mecplant® + 25% V), T4 (25% Mecplant® + 75% V) and T5 (75%
Mecplant® + 25% CRH). / Tabernaemontana catharinensis, conhecida popularmente como cobrina, é uma
árvore nativa, pertencente à família Apocynaceae. Essa espécie é indicada para
reflorestamento e rica em compostos fitoquímicos além de ser utilizada na medicina
popular na forma de chá ou infusão de suas folhas e cascas. Impactos decorrentes
da extração indiscriminada de sementes e partes vegetativas de espécies nativas
vêm crescendo nos últimos anos, sendo um dos desafios para a produção o cultivo
das plantas em larga escala de modo sustentável, sem o comprometimento dos
recursos naturais. Contudo muitas espécies ainda carecem de informações
ecológicas, fisiológicas e agronômicas. Assim, os objetivos deste trabalho foram
avaliar a qualidade fisiológica das sementes e os parâmetros morfofisiológicos de T.
catharinensis propagadas in vitro e ex vitro. Para isso, frutos maduros foram
coletados no terço médio lateral de cinco matrizes com cerca de quatro metros de
altura e localizadas em remanescente vegetal, no município de Ijuí, região Noroeste
do Rio Grande do Sul (28° 26' 07"S e 53° 57' 50"O). Os experimentos foram
desenvolvidos em condições de laboratório e em casa de vegetação. Em laboratório,
sementes foram colocadas para germinar na presença de luz (fotoperíodo de 16
horas) e ausência de luz (escuro contínuo), testando-se cinco temperaturas: 15, 20,
25, 30 ºC e alternada 20-30 ºC (noite-dia). Três condições e temperaturas de
armazenamento: 25 ±1 ºC (sala de crescimento), 10 ±1 ºC (refrigerador) e 4 ±1 ºC
(câmara fria), constituíram o experimento para verificar o comportamento
germinativo e o teor de água durante seis períodos de armazenamento das
sementes (30, 60, 90, 120, 150 e 180 dias). Observou-se que, independente do
regime de luz (fotoperíodo de 16 horas e escuro contínuo), temperaturas de 25 e 30
ºC, promoveram maior percentagem de germinação das sementes de T.
catharinensis. Sementes de T. catharinensis comportam-se como fotoblásticas
neutras. O armazenamento das sementes de T. catharinensis por 180 dias reduz o
teor de água das sementes, não ocorrendo redução no potencial germinativo,
demonstrando um comportamento ortodoxo. Nos experimentos em condições in
vitro, para obtenção de plântulas e estabelecimento de T. catharinensis, sementes
foram pré-imersas em ácido giberélico (GA3) nas concentrações de 0,0; 300 e 600
mg L-1 em dois regimes de tempo 24 e 48h. Posteriormente, segmentos
cotiledonares de 1 cm de plântulas obtidas da germinação in vitro, com 70 dias de
idade, foram inoculados em meio de cultura com 100% dos sais minerais de MS
(MURASHIGE; SKOOG, 1962), acrescidos das combinações de 6-benzilaminopurina
(BAP) 0,0; 1,0; 2,0; 4,0; 6,0 mg L-1 e ácido naftalenoacético (ANA) 0,0; 0,1; 0,2; 0,4;
0,6 mg L-1; para o experimento de enraizamento in vitro, microestacas de 90 dias,
com três pares de folhas, foram inoculadas em MS (MURASHIGE; SKOOG, 1962),
acrescido com concentrações de ácido indolbutírico (AIB) 0,0; 1,0; 2,0; 4,0; 6,0 mg L1. A percentagem de germinação não diferiu significativamente em sementes préimersas
em GA3, contudo ocorreu redução na velocidade de germinação nas
concentrações de 300 e 600 mg L-1 de GA3 por 48h de imersão. No estabelecimento
in vitro, ocorreu a organogênese direta de brotações adventícias de explantes
cotiledonares de cobrina sem a necessidade de fitorreguladores de crescimento,
porém o uso de BAP associado ao ANA maximizou o número de brotos, folhas e a
massa fresca de brotações. Para o experimento de enraizamento in vitro a
suplementação de 1,0 e 6,0 mg L-1 de AIB ao meio de cultura proporcionou maiores
taxas de enraizamento (96,5 e 89%, respectivamente) e comprimento de raiz (15,96
e 15,60 cm, respectivamente). A ausência de fitorreguladores de crescimento (AIB)
reduziu o número de pontas e volume de raízes e os teores de clorofila b. Para o
experimento em casa de vegetação, os tratamentos constaram de composições do
substrato Mecplant® (substrato comercial), vermiculita de textura fina (V) e casca de
arroz carbonizada (CAC), avaliando-se a influência destes na emergência, vigor e
nos parâmetros morfofisiológicos de T. catharinensis. Verificou-se que no uso
isolado de substrato comercial 100% Mecplant® ocorreu menor emergência e IVG de
plântulas, afetando negativamente as características de crescimento. O substrato
comercial associado ao material inerte vermiculita nas formulações 50% Mecplant® +
50% V e 25% Mecplant® + 75% V propiciaram maior expressão do vigor de
sementes e maior crescimento de mudas, evidenciando ser mais adequado, dentre
os estudados, para a formação de mudas de cobrina. Teores de clorofila a, b, total e
carotenoides não são influenciados pelos substratos formulados. A relação da
clorofila a/b é mais elevada nos tratamentos T2 (75% Mecplant® + 25% V), T4 (25%
Mecplant® + 75% V) e T5 (75% Mecplant® + 25% CAC).
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One Step Closer to Non-Invasive: Quantifying Coral Zooxanthellae Pigment Concentrations Using Bio-OpticsHancock, Harmony Alise 01 June 2012 (has links)
Due to the invasive nature of quantification techniques, baseline pigment data for coral-dwelling zooxanthellae are not known. In an attempt to develop a model for non-invasive estimation of zooxanthellae pigment concentrations from corals, field samples were taken from Porites rus and P. lutea in Apra Harbor, Guam. In-situ reflectance spectra (R400-R800) from 22 coral colonies were collected. “Coral truthing” was accomplished by extracting corresponding tissue core samples. Subsequent analysis to quantify the concentrations of 6 zooxanthellae pigments (µg cm-2) was performed using HPLC. Trials of multiple linear regressions were attempted (EJ Hochberg) and found inappropriate, despite previous success. The multivariate calibration technique partial least squares regression (PLS-R) is an excellent tool in the case of co-linear variables. Thus, PLS-R was attempted for chlorophyll c2 and peridinin after demonstration of co-linearity. This may be an appropriate approach for development of bio-optical models to estimate zooxanthellae pigment concentrations. Further, the dinoflagellate diagnostic pigment peridinin may be of great value for reef-scale remote sensing of changes in coral status in the future.
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The responses of ectohydric and endohydric mosses under ambient and enhanced ultraviolet radiationLappalainen, N. (Niina) 08 June 2010 (has links)
Abstract
Previous reports on the effects of enhanced UV-B radiation on bryophytes have been equivocal. This study shows that mosses not only respond to enhanced UV-B, but they are affected by changes in ambient radiation. The studies were conducted with two model species common in northern environments; red-stemmed feather moss (Pleurozium schreberi) and juniper haircap moss (Polytrichum juniperinum).
Both species showed high concentrations of methanol-extractable UV-absorbing compounds (UACs) with high spring-time and early-summer UV, whereas in P. juniperinum, the concentration was affected by early-summer drought. The UACs of P. juniperinum increased again towards autumn suggesting a role in winter hardening. The (spring-time) cell wall-bound UV screen was important to both species. The fundamental adaptation of P. juniperinum to open and exposed environments was reflected in relatively higher concentrations of total UACs compared to P. schreberi.
The enhanced UV-B experiments in situ were conducted over two years in Oulu and six years at the FUVIRC site in Sodankylä. Some of the effects of UV-B were seen within the first years of the experiments, or even within hours, while others were observed after several years. Five or six years of enhanced UV-B treatment increased the methanol-extractable UACs of P. schreberi and decreased the green shoot growth of P. juniperinum. The immediate light environment was proposed to have an impact on the varying UAC concentrations. Some mitigating effects of UV-A were observed as well.
Off-site measured, reconstructed and modelled UV radiation data was used for comparisons of light environment in situ, or when performing a reconstructive research with historical samples. The environmental sample banks can provide a useful tool to study past environmental conditions, and even reconstruct past radiation levels.
It was shown in this study that UACs in P. schreberi and P. juniperinum have fundamental roles as UV-B screens in the cell walls, but there is also a variable response with the soluble fraction that reacts and adapts to the changes in UV radiation. The responses to increasing UV-B radiation vary in magnitude and in time. As P. schreberi and P. juniperinum possess circumboreal and cosmopolitan distributions, the effects of UV-B on these species and consequently on ecosystems has a broad application.
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Badatelsky orientovaná výuka rostlinných barviv na 2. stupni ZŠ / Inquiry-based science education of plant pigments in upper primary schoolNovotná, Apolena January 2017 (has links)
This thesis is focused on interconnection between education of plant pigments and inquiry- based science education in upper primary school. The theoretical section of this thesis deals with the current quality of education and knowledge level of Czech pupils in science subjects, as well as characteristic of inquiry based science education and description of various types of plant pigments. Evaluation of publications focused on occurrence of plant pigments in curricular document is another part of this thesis. The study revealed that plant pigments represent only a marginal topic of these publications. The next section of this thesis is a questionnaire survey about utilization of inquiry based science education among the teachers of biology in upper primary school. The results showed that most of the teachers were well acquainted with the method and applied it during their teaching. The last section of this thesis contains two proposals for experimental tasks of inquiry-based science education of plant pigments, which are focused on interface of biology and chemistry. Both tasks were successfully solved.
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Studium elektronových přeskoků v systému barviv fotosystémů metodami kvantové mechaniky. Simulace absorpčních a emisních fotoelektronových spekter. / Quantum mechanical study of the electron hoping processes of pigments from photosystems. Simulation of absorption and emission photoelectron spectra.Cajzl, Radim January 2017 (has links)
Title: Quantum mechanical study of the electron hoping processes of pig- ments from photosystems. Simulation of absorption and emission photoelectron spectra. Author: Bc. Radim Cajzl Department: Department of Chemical Physics and Optics Supervisor: prof. RNDr. Ing. Jaroslav Burda, DrSc., Department of Chemical Physics and Optics Abstract: The aim of this thesis is to develop a methodology for simulation of dynamical properties of carotenoids by OMx method combined with surface electron hopping. We use linear conjugated polyenes: ethene, butadiene, hexa- triene up to polyenes with 22 carbon atoms as model systems. First, the spectra are calculated with sufficiently good agreement with the experimental data by both correct order of excited states and small deviation from experimental data. These results are used for electron surface hopping for calculation of mean lifetimes of excited states of studied polyenes. Calculated lifetimes are of the same order as experimental data for butadiene, hexatriene and octatetraene. Calculated lifetimes for poleynes with 20 resp. 22 carbon atoms agree well with chemically analogous carotenoids. Keywords: quantum mechanics, photoelectron spectra, pigments of photosys- tems, elecrton transitions, molecular and electronic dynamics
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