Orientador: Renate Krause Sakate / Coorientador: Marcelo Agenor Pavan / Banca: Antonio Carlos Maringoni / Banca: Kelly Cristins Gonçalves Rocha / Banca: Jorge Alberto Marques Rezende / Banca: Tatiana Mituti / Resumo: O gênero Allium inclui espécies de importância para o consumo humano como o alho, cebola e espécies ornamentais. Algumas destas espécies por serem propagadas vegetativamente, podem ser infectadas por vírus pertencentes aos gêneros Allexivirus, Carlavirus e Potyvirus, frequentemente em infecções mistas. Leek yellow stripe virus (LYSV) pertence ao gênero Potyvirus e é considerada a espécie de maior importância na cultura do alho, de modo que foi sequenciado o genoma completo de um isolado de LYSV brasileiro (LYSV-MG) e avaliada sua diversidade genética. Seu genoma possui 10.341 nucleotídeos e codifica uma poliproteína de 3221 aminoácidos. Baseado na análise da região codificadora para a proteína P1, o isolado LYSV-MG, bem como demais coletados em regiões produtoras de alho, não foram classificados como pertencentes aos grupos S e N. Os isolados brasileiros apesar de não apresentarem a deleção na região da P1 (típica do grupo S), formaram um grupo monofilético muito próximo deste grupo e de um isolado de Okinawa, Japão. Em relação ao gene P1, os isolados brasileiros compartilharam 97-99% de identidade de nucleotídeos entre si e 51-64% com isolados de LYSV de outros países. Os dados sugerem que os isolados brasileiros de LYSV, o isolado de Okinawa e os isolados pertencentes ao grupo S podem ser provenientes de um ancestral comum antes da ocorrência da deleção na P1 e divergência dos isolados no grupo S. Como parte do doutoramento sanduíche, realizado na United States Department of Agriculture, sob orientação do Dr. John Hammond, foram estudados os vírus presentes em quatorze diferentes espécies de Allium ornamental nos Estados Unidos. As plantas foram adquiridas em floriculturas e plantadas a campo no outono de 2013 na região de Beltsville, MD. Folhas sintomáticas foram coletadas após a floração durante a primavera de 2014 e avaliadas por PCR usando primers ... / Abstract: The genus Allium includes important species used for human consumption, as garlic,onion and many other species grown as ornamentals. Some of these species are propagated vegetatively and can be infected by viruses belonging to the genera Allexivirus, Carlavirus and Potyvirus, often in mixed infections. Leek yellow stripe virus (LYSV) belongs to the genus Potyvirus and is considered the most important virus in Allium species. The complete genomic sequence of Leek yellow stripe virus garlic isolate from Brazil (LYSV-MG) has been determined. The LYSV-MG genome consists of 10,341 nucleotides and encodes a deduced polyprotein of 3,221 amino acids. Based on the analysis of the coding region for P1 protein, isolate LYSV-MG and others collected in garlic producing regions, could not be classified as belonging to the groups S and N. Brazilian isolates do not have the deletion present in the P1 from the S-type group but are more closely related to S-type than to N-type isolates. The Brazilian isolates formed a monophyletic group closer to S-type and one isolate from Okinawa, Japan. Brazilian isolates share 97-99% of P1 region nucleotide identity with each other, and 51-64% with different isolates from around the world. The data suggest that Brazilian LYSV isolates are derived from an ancestral source of the Okinawa and S-type isolates, prior to the P1 deletion and divergence in the S-type isolates. As part of the doctorate sandwich in United States Department of Agriculture, under the supervision of Dr. John Hammond, viruses present in ornamental Allium from Beltsville, MD were detected. Bulbs of fourteen different species of Allium were purchased from retail nurseries and planted in the field during the fall of 2013. Leaf tissue from the flowering symptomatic plants were collected during spring 2014, and tested by PCR using generic primers for the genus Allexivirus, Carlavirus and Potyvirus. PCR-positive ... / Doutor

Orientador: Dirceu Maximino Fernandes / Banca: Roberto Lyra Villas Bôas / Banca: Shizuo Seno / Resumo: A produção de alho em regiões de cerrado, com solos ácidos, pobres em fósforo e elevada fixação desse nutriente,demanda aplicaçõesde adubos fosfatados e corretivos de acidez de forma adequada. Com o objetivo de verificar o efeito de níveis de saturação por bases e combinações de fontes de fósforo no solo,em alho vernalizado livre de vírus, foi conduzido experimento em casa de vegetação no Departamento de Solos e Recursos Ambientais - FCA/UNESP, utilizando-se vasos com 13 L de solo oxídico oriundo da região de Santa Juliana/MG. O delineamento experimental foi em blocos ao acaso com quatro repetições, em esquema fatorial com três níveis de saturação por bases (50, 65 e 80%) e três combinações de fontes de fósforo (superfosfato simples, superfosfato simples+termofosfato1 e superfosfato simples+termofosfato 2). Os níveis de saturação por bases e/ou a combinação de fontes de fósforo influenciaram o número total de folhas por planta, o teor e acúmulo de nutrientes na parte aérea no momento da diferenciação, a massao acúmulo de nutrientes nos bulbos, a atividade antioxidante e o teor de fenóis totais nos bulbilhos / Abstract: Garlic yield in "cerrado" soils whichareacid, poor in phosphorus and high in this nutrientfixation, requires applications of phosphate fertilizers and soil acidity correctivesadequately. In orderto evaluate the effectofsoil base saturationlevelsand phosphorus sources combinations in vernalized virus-freegarlic, this experiment was carried out ina greenhouse at the Department of Soil and Environmental Resources - FCA / UNESP, usingpots containing13 L of oxidicsoilcoming from SantaJuliana/MG. The experiment was arranged in a randomized block design, with four replications, in split-plot scheme, with three levels ofsoil base saturation(50,65 and 80%) and threephosphorus sources combinations (single superphosphate, single superphosphate + thermophosphate 1, single superphosphate + thermophosphate 2). Soil base saturation levels and/or phosphorus sources combinations affected thetotal number of leaves per plant, nutrients content and accumulationin the shoot in differentiation phase, bulbs weightand nutrient accumulation, antioxidant activityandtotal phenolscompounds contents incloves / Mestre

During the past decade there has been an explosion in the probiotic industry due to an increase in concern for health. It is well known that these probiotic products offer consumers numerous health benefits and that viability of cultures in these products need to be maintained at high levels. It is therefore important to test for antimicrobial compounds or substances that may come into contact with probiotics and thereby negatively affect and decrease their viability. Garlic (Allium sativum) has been used as a natural medicinal remedy for thousands of years and research has shown that it has antimicrobial activity against a wide variety of microorganisms. Although it has been tested against numerous pathogenic microorganisms, there have been few studies on its effect on beneficial bacteria, specifically probiotic Bifidobacterium species. A great amount of work and money is put into preparing probiotic products with sufficient numbers of viable bacterial cells. All these are devoted to ensure that the consumers seize the optimal purported health benefits from probiotic cultures incorporated within the different products. Hence it is necessary to recognize any compound or substance that poses a threat to viability of these probiotic cells, thereby rendering them ineffective. Therefore, the current study aimed at determining whether garlic had any antibacterial activity towards selected Bifidobacterium spp. In vitro studies revealed that garlic has an inhibitory effect on these specific probiotic bacteria. The disk diffusion assay revealed antibacterial activity of garlic preparations characterized by inhibition zones ranging from 13.0 ± 1.7 to 36.7 ± 1.2 mm. Minimum inhibitory concentration (MIC) values for garlic clove extract ranged from 75.9 to 303.5 mg/ml (estimated to contain 24.84 to 99.37 μg/ml allicin) while the minimum bactericidal concentration (MBC) ranged from 10.24 to 198.74 μg/ml xix allicin. Susceptibility of the tested Bifidobacterium species to garlic varied between species as well as between strains even within a small numbers of the tested bifidobacteria. Among the tested Bifidobacterium spp., B. bifidum LMG 11041 was most susceptible to garlic, whereas B. lactis Bi-07 300B was the most resistant. These results were contrary to what has been generally published in literature, that garlic selectively kills pathogens without negatively affecting beneficial bacteria. Garlic clove, garlic powder, garlic paste and garlic spice showed varying degrees of potency, with fresh garlic clove extract and garlic paste extract having the highest and lowest antibifidobacterial activity, respectively. It became necessary to investigate the actual antibacterial mechanism of action of garlic on Bifidobacterium spp., upon realization that its extracts inhibits growth of or kills some of these bacteria, whose contribution to health and well being of consumers is to a large extent dependent on their viability. This was determined by using scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy. Scanning electron microscopy was used to investigate the effect of garlic on the morphology and cell surface properties of the tested strains while FT-IR spectroscopy was used to determine any biochemical changes taking place in garlic-treated bifidobacteria. Scanning electron microscopy showed various morphological changes such as cell elongation, distorted cells with bulbous ends and cocci-shaped cells. Behavioural changes were also observed such as swarming of cells was also observed. FT-IR spectra confirmed that garlic damaged Bifidobacterium cells by inducing biochemical changes within the cells. It identified some of the main targets sites of garlic on bifidobacteria, mainly, the nucleic acids and fatty acids (lipids) in the cell membrane. Flow cytometry analysis was used to determine the level at which the garlic decreased the viability of Bifidobacterium cells as well as the extent of damage induced by the garlic. Results revealed a drop in viability with associated decrease in stainability of some the cells, for all strains upon treatment with garlic clove extract. The inability of cells to be stained by nucleic acid stains, hence presence of cells referred to as ‘ghost cells’, has been associated with extensive damage and lysis of cellular membranes resulting in loss nucleic acids. Interestingly, re-inoculation of the cells analysed by flow cytometry into a fresh growth medium and their subsequent reanalysis using the same technique showed an increase in percentage of viable cells and a decrease in percentages of damaged, unstained and dead cells. This suggested that injured cells were able to recover and regress to their active state. Therefore, Bifidobacterium cells exposed to sub lethal amounts of garlic can repair any damage and regrow. However, it was not determined how long active compounds of garlic remain stable within the gastrointestinal tract. This study is the first, according to our knowledge, to show that garlic exhibits antibacterial activity against beneficial bacteria specifically, probiotic bifidobacteria. Furthermore, the results revealed that the mechanism of action of garlic towards bifidobacteria is similar to that which was reported for pathogenic bacteria. Bacterial death and growth inhibition occurs due to damage to the fatty acids/lipids in the cell membrane, modification of the nucleic acids (DNA and RNA). This study is of significant importance to consumers, medical practitioners as well as to the probiotic industry. It suggests that if garlic comes into contact with probiotic bifidobacteria, they die and thus become unable to deliver the promised health benefits to the consumers. Therefore, consumers should be advised against ingestion of probiotic products and garlic simultaneously, as this study reveals that garlic does indeed inhibit some probiotic Bifidobacterium spp. The probiotic industry should also consider including this information on their product labels to make consumers aware of this fact. Failure to include this information may lead to market deterioration due to loss of interest in the products as soon as consumers realize they do not get their money’s worth from the products. Lastly, medical practitioners should also be made aware of this as they also prescribe probiotics to patients for various health reasons. The effect of food matrices on the antibacterial effects, as well as determination of how long the active compounds of garlic remain within the gastrointestinal tract, in relation to levels of garlic ingested will confirm whether indeed there is concern. But for now, in light of results of the current study, caution needs to be taken in simultaneous use of probiotics and garlic, until further testing indicates otherwise. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Microbiology and Plant Pathology / unrestricted

Indiana University-Purdue University Indianapolis (IUPUI) / Invasive exotic species have caused severe ecological and economic damages to many communities in the United States and elsewhere. It is therefore important to improve our understanding of how global environmental changes will affect the invasiveness and severity of these invasive species. Over the last century, anthropogenic activities have caused multiple environmental changes. Previous studies have generally focused on the impact of the increasing atmospheric CO2 level on the physiology and growth of invasive species. With atmospheric nitrogen (N) deposition on the rise over the past decades, it is essential to recognize how an increase in soil N will affect the invasiveness of some exotic species. To determine the impact of increased atmospheric N deposition and drought stress on invasive species, I studied the impact of different levels of N on Alliaria petiolata (garlic mustard), an exotic invasive species. In addition, I examined the interactive effects of N deposition and drought stress on garlic mustard. Multiple morphological measurements were used to analyze the growth rate at varying levels of N and soil moisture. The study on N deposition on plant growth will improve our understanding of the invasiveness of garlic mustard. The changes in precipitation patterns must also be examined to foresee if plants in increased atmospheric N conditions can overcome drought stress conditions. I found an increase in plant growth and photosynthetic rate at higher levels of N. Plants with adequate water displayed a continued increase from the lowest level to the highest level of N. Increases in drought stressed plants plateaued at an intermediate N level of 20 kg ha-1. My results demonstrated that during drought stress garlic mustard does not benefit from an increase in N above a certain level. These results are important to take into consideration when we analyze the spreading of invasive weeds due to global environmental changes, including increased atmospheric N deposition and regional drought, in order to apply the optimal management strategies for controlling invasive species.

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Garlic mustard (Alliaria petiolata, Brassicaceae) is a biennial herb that produces glucosinolates, a class of constituent secondary metabolites that defend against herbivores and pathogens allowing it to grow at high densities in invaded regions. The glucosinolate sinigrin is predominant in garlic mustard and aids in its competitiveness as an invasive species. In North America, garlic mustard can grow at high densities and form dense monocultures which may increase its apparency to herbivores and therefore increase its sinigrin production. I measured leaf sinigrin concentration in garlic mustard populations of different densities in the field and in greenhouse experiments to evaluate the response of sinigrin concentration and growth to density and light. Sinigrin concentrations of second-year plants were negatively correlated with growth metrics across all field densities; indicating a cost to sinigrin production. In the greenhouse density experiment with high and low rosette stem densities, sinigrin differed significantly by rosette density category. A factorial greenhouse experiment with light and density treatments discerned significant differences in sinigrin concentration by density. These findings suggest that sinigrin concentration may be influenced by intraspecific density across different light environments.

Objetivo. A busca por produtos de alho prontos para consumo cresceu na última década. O alho contém compostos fenólicos e organosulfurados, que são responsáveis pelo odor característico, sabor, aroma e ação antioxidante. Este estudo teve como objetivo avaliar a atividade antioxidante e determinar os compostos fenólicos totais em alho in natura e em seus produtos comercializados, além de avaliar o impacto dos aditivos (ácido cítrico, metabisulfito de sódio e benzoato de sódio) sobre a atividade antioxidante. Métodos. Extratos metanólicos de alho in natura (AIN) e seus produtos picado com sal (APS), picado sem sal (AP), frito (AF) e misto – mistura de alho in natura com alho desidratado (AM) foram analisados pela vida de prateleira (em três momentos), nos parâmetros: teor de fenólicos totais e atividade antioxidante por três métodos: ensaio DPPH (1,1-difenil-2-picrilhidrazil), sistema β-caroteno/ácido linoléico e capacidade protetora da oxidação lipídica utilizando o aparelho Rancimat®. Resultados. O teor de fenólicos totais do extrato em relação ao resíduo seco foi maior para o produto frito, nos três momentos. Em relação à atividade antioxidante, o alho frito foi o produto que apresentou melhor atividade para todos os testes. Ao longo da vida de prateleira, a atividade antioxidante diminuiu com o ensaio DPPH, sendo que para os demais testes, aumentou. Os produtos com aditivos apresentaram melhor atividade antioxidante, apesar de apresentarem menor teor de fenólicos totais. Conclusões. Este estudo reforçou o potencial antioxidante do alho, portanto o seu consumo pode ser recomendado como parte de uma dieta saudável. Além disso, observou-se que a presença de aditivos melhorou o efeito antioxidante das amostras. / Objective. The interest for ready-to-eat garlic byproducts increased in the last decade. Garlic has phenolic and sulfur compounds, which are responsible for the singular flavor and antioxidant activity. This study aimed to evaluate the antioxidant activity (AA) of in natura garlic and its commercialized byproducts, and to correlate the data with phenolics contents. The impact of additives (citric acid, sodium metabisulfite and sodium benzoate) on the AA was also evaluated. Methodology. Methanolic extracts of in natura garlic (ING) and its products, i.e., chopped with salt (CWP), chopped without salt (CS), fried (FG) and mixed garlic - in natura garlic with dehydrated garlic (MG) were evaluated in three different moments of the shelf life. This evaluation based on the measurement of the following parameters: total phenolic compounds and AA. The AA were evaluated using three different methods: DPPH (1,1- diphenyl-2-picrylhydrazyl) assay, β-carotene/linoleic acid system and Rancimat® method. Results. The total phenolics content of the extract in relation to the dried residue was higher in the fried product, in the three moments. Regarding the AA, fried garlic showed the best activity in all tests. Throughout the shelf life, the AA decreased with the DPPH assays. In contrast, when the other tests were applied, the AA increased. The products with additives showed better antioxidant activity when compared to those without the additives, although the samples with additives showed lower content of total phenolics. Conclusion. This study strengthened the antioxidant potential of garlic, therefore its consumption should be recommended as part of a healthy diet. Moreover, it was observed that the presence of additives improved the antioxidant effect of the samples.

Objetivo. A busca por produtos de alho prontos para consumo cresceu na última década. O alho contém compostos fenólicos e organosulfurados, que são responsáveis pelo odor característico, sabor, aroma e ação antioxidante. Este estudo teve como objetivo avaliar a atividade antioxidante e determinar os compostos fenólicos totais em alho in natura e em seus produtos comercializados, além de avaliar o impacto dos aditivos (ácido cítrico, metabisulfito de sódio e benzoato de sódio) sobre a atividade antioxidante. Métodos. Extratos metanólicos de alho in natura (AIN) e seus produtos picado com sal (APS), picado sem sal (AP), frito (AF) e misto – mistura de alho in natura com alho desidratado (AM) foram analisados pela vida de prateleira (em três momentos), nos parâmetros: teor de fenólicos totais e atividade antioxidante por três métodos: ensaio DPPH (1,1-difenil-2-picrilhidrazil), sistema β-caroteno/ácido linoléico e capacidade protetora da oxidação lipídica utilizando o aparelho Rancimat®. Resultados. O teor de fenólicos totais do extrato em relação ao resíduo seco foi maior para o produto frito, nos três momentos. Em relação à atividade antioxidante, o alho frito foi o produto que apresentou melhor atividade para todos os testes. Ao longo da vida de prateleira, a atividade antioxidante diminuiu com o ensaio DPPH, sendo que para os demais testes, aumentou. Os produtos com aditivos apresentaram melhor atividade antioxidante, apesar de apresentarem menor teor de fenólicos totais. Conclusões. Este estudo reforçou o potencial antioxidante do alho, portanto o seu consumo pode ser recomendado como parte de uma dieta saudável. Além disso, observou-se que a presença de aditivos melhorou o efeito antioxidante das amostras. / Objective. The interest for ready-to-eat garlic byproducts increased in the last decade. Garlic has phenolic and sulfur compounds, which are responsible for the singular flavor and antioxidant activity. This study aimed to evaluate the antioxidant activity (AA) of in natura garlic and its commercialized byproducts, and to correlate the data with phenolics contents. The impact of additives (citric acid, sodium metabisulfite and sodium benzoate) on the AA was also evaluated. Methodology. Methanolic extracts of in natura garlic (ING) and its products, i.e., chopped with salt (CWP), chopped without salt (CS), fried (FG) and mixed garlic - in natura garlic with dehydrated garlic (MG) were evaluated in three different moments of the shelf life. This evaluation based on the measurement of the following parameters: total phenolic compounds and AA. The AA were evaluated using three different methods: DPPH (1,1- diphenyl-2-picrylhydrazyl) assay, β-carotene/linoleic acid system and Rancimat® method. Results. The total phenolics content of the extract in relation to the dried residue was higher in the fried product, in the three moments. Regarding the AA, fried garlic showed the best activity in all tests. Throughout the shelf life, the AA decreased with the DPPH assays. In contrast, when the other tests were applied, the AA increased. The products with additives showed better antioxidant activity when compared to those without the additives, although the samples with additives showed lower content of total phenolics. Conclusion. This study strengthened the antioxidant potential of garlic, therefore its consumption should be recommended as part of a healthy diet. Moreover, it was observed that the presence of additives improved the antioxidant effect of the samples.