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Effect of common seed, soil and storage pathogens on soybean seed quality testing /Gupta, Indra Jeet January 1984 (has links)
No description available.
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Some aspects of biological control of seed storage fungi.Calistru, Claudia. January 1995 (has links)
Under storage conditions of ambient temperature and relative humidity in South Africa, seed-associated mycoflora proliferates. Fusarium moniliforme is ubiquitous in newly-harvested maize, persisting for variable periods in storage, while Aspergillus flavus may represent the final group of species in the succession of aspergilli after grain storage under high temperature and/or high humidity. Many strains of these fungi produce toxigenic secondary metabolites (mycotoxins) under local storage conditions. Since pathogenic fungi may be present within the tissues of stored seeds, these contaminants will not be eradicated by external fungicide treatment, therefore a possible alternative is biological control. The aim of the present investigation was to ascertain whether certain strains and/or species of Trichoderma have potential as biocontrol agents against the seed-associated pathogenic fungi, Aspergillus flavus and Fusarium moniliforme. A study of the fungal growth in dual cultures revealed that from nine isolates of Trichoderma spp. (T harzianum and T viride), four had a noticeable inhibitory effect on the growth of the pathogenic fungi. Scanning electron microscopical investigation of fungal interaction demonstrated no obvious hyphal penetration by - Trichoderma spp. In addition, significant alteration of Fusarium hyphae, with pronounced collapse and loss of turgor, and production of aberrant conidial heads and microheads by A. flavus were observed. Evidence derived from some biochemical studies revealed that antibiosis (by production of extracellular enzymes, volatile compounds and possible antibiotics) is probably the mechanism involved in the antagonistic effect of the four aggressive Trichoderma spp. The in vitro studies demonstrated that the use of Trichoderma spp. as biocontrol agents against A. flavus and F. moniliforme appears promising. / Thesis (M.Sc.)-University of Natal, 1995.
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Regiões de produção na qualidade física, fisiológica e sanitária de sementes de Brachiaria brizantha cv. BRS Piatã / Regions of production in the physical, physiological and sanitary quality of seeds of Brachiaria brizantha cv. BRS PiatãSilva, Givanildo Zildo da 11 September 2017 (has links)
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Previous issue date: 2017-09-11 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A qualidade das sementes é influenciada pelas condições climáticas e fitossanitárias do campo de produção. A identificação das características das melhores áreas produtoras de sementes de forrageiras permite aprimoramento do setor. Assim, a presente pesquisa teve como objetivo identificar características climáticas das regiões produtoras que podem afetar a qualidade física, fisiológica e sanitária de sementes de Brachiaria brizantha cv. BRS Piatã. Foram avaliados 10 lotes de sementes de B. brizantha procedentes dos Estados de São Paulo, Goiás, Bahia, Minas Gerais e Mato Grosso do Sul. Avaliaram-se dois lotes de sementes de cada Estado pelas seguintes determinações: pureza, massa de mil sementes, teor de água, viabilidade pelo teste de tetrazólio, germinação e os testes de vigor de emergência, primeira contagem de emergência de plântulas em areia e emergência das plântulas em campo. Também foi avaliada a qualidade sanitária das sementes pelo método do papel de filtro. Foram obtidos dados de temperatura e precipitação desde o período de florescimento até a colheita das sementes de cada região de produção. As médias dos tratamentos foram comparadas pelo teste de Scott Knott, a 5% de probabilidade. Para discriminar as regiões que produzem lotes de sementes de melhor qualidade e quais fatores ambientais têm influência sobre cada um dos parâmetros de qualidade das sementes aplicou-se a análise estatística multivariada pela Análise de Componentes Principais. Locais de produção com temperaturas acima de 30 ºC nas épocas de florescimento, degrana e colheita estão relacionadas à produção de sementes de capim-piatã de menor qualidade física e fisiológica. Do mesmo modo precipitações pluviométricas acumuladas superiores a 500 e 137 mm no florescimento e colheita, respectivamente, são desfavoráveis ao vigor de sementes produzidas. Fusarium spp. predominou em locais cujo ambiente na colheita apresentou: temperaturas máximas superiores à 30 ºC, médias próximas à 25 ºC e acúmulo de chuva inferior à 82 mm. A incidência de Bipolaris sp. em sementes de capim-piatã é favorecida por locais com temperaturas entre 19 e 20 ºC na maturação. A maior incidência de Exserohilum sp. ocorre em locais cuja temperatura durante a colheita é próxima à 20 ºC e a precipitação pluviométrica acumulada situa-se entre 167 e 181 mm. / Seed quality is influenced by climatic and phytosanitary conditions of the field of production. The identification of the characteristics of the best forage seed producing areas allows the sector improvement . Thus, this research aimed to identify climatic characteristics of the producing regions that can affect the physical, physiological and sanitary quality of seeds of Brachiaria brizantha cv. BRS Piatã. Ten seed lots of B. brizantha from the states of São Paulo, Goiás, Bahia, Minas Gerais and Mato Grosso do Sul were evaluated. Two seed lots of each state were evaluated by means the following determinations: purity, mass of a thousand seeds, water content, viability by the tetrazolium test, germination and emergence vigor tests, first count of seedling emergence in sand and seedling emergence in the field. The sanitary quality of the seeds was also evaluated by the filter paper method. Temperature and precipitation data were obtained from the flowering period to the harvest of the seeds of each production region. Treatment means were compared by the Scott Knott test at 5% of probability. To discriminate the regions that produce seed lots of better quality and which environmental factors have influence on which parameters of seed quality was applied the multivariate statistical analysis through Principal Component Analysis. Production sites with temperatures above 30 °C during flowering, degrane and harvest are related to the production of lower quality piatã grass seeds. In the same way cumulative rainfall higher 500 and 137 mm in flowering and harvest, respectively, are unfavorable to seed vigor produced. Fusarium spp. maximum temperature was higher than 30 ºC, mean values close to 25 ºC and lower rainfall, less than 82 mm. The incidence of Bipolaris sp. in seeds of piatã grass is favored by sites with temperatures between 19 and 20 ºC in maturation. The higher incidence of Exserohilum sp. occurs at sites in whose harvest temperatures is close to 20 °C and cumulative rainfall is between 167 and 181 mm.
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Improving Rangeland Seedling Recruitment Using Fungicide Seed Coatings and Golden Eagle Reproductive Success in Relation to Explosive Military Tests and TrainingsHoose, Benjamin William 30 November 2020 (has links)
The objective of the first chapter of this thesis was to determine whether fungicide seed coatings constitute an effective strategy for increasing seedling recruitment in restoration scenarios in the Intermountain West. We tested a mixture of four fungicides that address potential fungal pathogens to bluebunch wheatgrass, a dominant bunchgrass that is commonly used in restoration. Across two sites and three years, we found that the fungicide seed coating increased emergence in five of the six sites and years, with an average increase of 59.1% over the control. There was a strong interaction (P < 0.001) between the effects of fungicide treatment, the year and the site on emergence. This interaction was likely related to the effects of the hydrothermal microsite environment on disease severity. Further research is necessary to fully understand the conditions under which fungicide seed coatings are most likely to be effective. The objectives the second chapter of this thesis were to 1) estimate the effects of golden eagle nest proximity to explosive disturbances on reproductive success given other relevant habitat variables (e.g. indices of topography and vegetation), and 2) determine the relative importance of nest proximity to explosive disturbances as a predictor of golden eagle reproductive success compared to other relevant habitat variables. Reproductive success data were collected from nesting territories within and surrounding land controlled and managed by the US Department of Defense. We fit the reproductive survey data using generalized linear mixed-effects models comprised of unique, hypothesis-based sets of habitat variables. We compared the models using AICc-based model selection processes. Given the best approximating model, we found no evidence that the likelihood of reproductive success was affected by nest proximity to explosive disturbances (P = 0.460). We further found nest proximity to explosive disturbances consistently ranked in the bottom 50% of relative variable importance. These results may indicate golden eagle tolerance or habituation to explosive military tests and trainings. Although the two chapters of this thesis are disjointed, they are loosely unified by the ecological importance of disturbance, invasive species, and restoration within the Great Basin ecoregion.
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Sclerotinia sclerotiorum em sementes de soja: sobrevivência, efeito na germinação, tamanho de amostra para análise e eficiência in vitro de fungicidas / Sclerotinia sclerotiorum in soybean seeds: survival, effect on germination, sample size for analysis and in vitro efficiency of fungicidesCamargo, Meyriele Pires de 27 January 2014 (has links)
O fungo Sclerotinia sclerotiorum, agente causal do mofo branco, encontra-se disseminado em todo o país e afeta mais de 400 espécies de plantas, dentre elas a cultura da soja, causando danos consideráveis no rendimento. A transmissão do patógeno ocorre por meio de sementes contendo micélio dormente ou pela presença de escleródios no lote, os quais podem permanecer viáveis por um longo período, dificultando o manejo da doença. Este trabalho teve como objetivos verificar a viabilidade do patógeno em sementes durante o armazenamento e seu efeito sobre o poder germinativo; comparar tamanhos de amostras de sementes visando à detecção do fungo; e avaliar a sensibilidade in vitro de S. sclerotiorum a fungicidas. Para avaliação da sobrevivência do patógeno, sementes de soja foram inoculadas, artificialmente, com três isolados de S. sclerotiorum, e armazenadas em duas condições, câmara fria e seca (20 ºC e 45% UR) e ambiente não controlado, durante oito meses. A cada dois meses foram realizados testes de sanidade pelo meio de cultura ágar-bromofenol (Neon), utilizando-se 4 repetições de 100 sementes, e testes de germinação, com 4 repetições de 50 sementes, pelo método do rolo de papel. No experimento de amostragem foram avaliadas dez amostras de sementes de soja pelo método do meio Neon, comparando-se quatro tamanhos de amostra: 400, 800, 1600 e 2400 sementes. Para avaliação da sensibilidade in vitro de S. sclerotiorum a fungicidas, foram utilizados 13 ingredientes ativos, em 7 doses e 5 repetições. Os valores da concentração inibitória de 50% (CI50) e 100% (CI100) foram estimados com base na percentagem de inibição do crescimento micelial. Além disso, realizaram-se a quantificação e pesagem dos escleródios formados após 15 dias de incubação. A presença do patógeno S. sclerotiorum, afetou negativamente a germinação das sementes, com redução média de 32% em relação à testemunha. Verificou-se diferença entre os isolados com relação à agressividade. O patógeno sobreviveu nas sementes em ambos os ambientes de armazenamento, porém, em ambiente controlado a redução na geminação das sementes foi de 14% e na incidência do fungo de 16%, enquanto que, em laboratório, esta redução foi de 23% na germinação e de 62% na incidência. Não houve diferença estatística com relação à quantidade de sementes amostradas na detecção de S. sclerotiorum, entretanto, constatou-se maior frequência de ocorrência do patógeno à medida que o número de sementes amostrado foi maior. Todos os fungicidas foram capazes de reduzir o crescimento micelial de S. sclerotiorum, bem como a produção de escleródios, sendo que os ingredientes ativos piraclostrobina, carbendazim, tiabendazol e tiofanato metílico, além de apresentarem CI50 inferior a 1 mg L-1, também inibiram totalmente a formação de escleródios em concentrações inferiores a 5 mg L-1. / The fungus Sclerotinia sclerotiorum, the causal agent of white mold is spread throughout the country and affects more than 400 species of plants, including soybean, causing considerable decrease in yield. The pathogen transmission occurs through seeds with dormant mycelium or by the presence of sclerotia in the lot, which can remain viable for a longer period, making hard the disease management. This study aimed to verify the viability of the pathogen in seeds during the storage period and its effect on germinative power; compare sizes of seed samples to determine the presence of the fungus; and to evaluate the in vitro sensibility of S. sclerotiorum to fungicides. To determine the pathogen survival, soybean seeds were inoculated artificially with three isolates of S. sclerotiorum, and stored into two conditions, cold and dry chamber (20 °C and 45% RU) and in uncontrolled environment, for eight months. Every two months health tests were performed by culture media bromophenol agar (Neon), using 4 repetition of 100 seeds, and germination tests, with 4 repetition of 50 seeds, by the method of the paper roll. During the experiment of sampling, ten samples of soybean seeds were evaluated by the method of media Neon, comparing four sample sizes: 400, 800, 1600 and 2400 seeds. To evaluate the in vitro sensibility of S. Sclerotinia to fungicides were used 13 active ingredients, in 7 doses and 5 repetitions. The values of the 50% inhibitory concentration (IC50) and 100% (IC100) were estimated based on the percentage inhibition of the mycelial growth. In addition, it was performed the quantification and weighing of sclerotia formed after 15 days of incubation. The pathogen S. sclerotiorum in soybean seeds affected negatively the germination of seeds, with an average reduction of 32% compared to the control. There was difference between the isolates in relation to aggressiveness. The pathogen survived in seeds in both storage environments, however, under controlled environment, the decrease in the germination of the seeds was 14% and in its incidence was 16%, while in laboratory this reduction was 23% in the germination and 62% in the incidence. There was no statistical difference in the quantity of seeds sampled in the detection of S. sclerotiorum, however, a higher frequency of pathogen occurrence was verified as the number of sampled seeds was enlarged. All fungicides were able to reduce the mycelial growth of S. sclerotiorum and sclerotia production, and the active ingredients pyraclostrobin, carbendazim, thiabendazole and thiophanate methyl, besides having IC50 of less than 1 mg L-1 also completely inhibited the formation of sclerotia in concentrations less than 5 mg L-1.
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Towards developing effective decontamination procedures for in vitro culture of embryonic axes excised from recalcitrant seeds.Cherian, Jency. 27 May 2014 (has links)
Control of seed-associated micro-organisms is vital in reducing losses of plants of economic
importance. Recalcitrant seeds being metabolically active and able to be stored only under conditions
of high relative humidity makes it more difficult to control contaminants. Nevertheless, means need to
be developed to eliminate, or at least curtail, seed-associated fungi and bacteria. The use of biological
control is a highly recommended alternative to chemical control for reducing the risk of killing
beneficial organisms, as well as in terms of health and environmental hazards. Furthermore, when
working with seed-derived tissues, it is extremely important to optimise a method or methods to
control contamination without compromising the viability or further development of the explants.
The original aim of the present study was to determine whether the biocontrol agents, EcoT® and
Eco77® (commercial products of the spores of Trichoderma harzianum) would effectively
control/eliminate micro-organisms from the embryonic axes of Trichilia dregeana, while promoting
growth under in vitro conditions. Other means were also tested for their efficacy in controlling
contaminants; these were application of Benlate®, Nipastat® (a mixture of parabens), anodic water
(the anodic fraction of an electrolysed dilute solution of calcium and magnesium chloride), sodium
dichloro-isocyanurate (Medi-Chlor®[NaDCC]) and alginate gel encapsulation of the embryonic axes.
Prior to the experiments, fungal contaminants from the embryonic axes were isolated on potato
dextrose medium and identified using light microscopy. EcoT and Eco77 were initially individually
tested by co-culture as conidial suspensions with the embryonic axes. A further approach used liquid
culture (potato dextrose broth) as well as solid culture medium (based on sugarcane bagasse) in/on
which the strains of Trichoderma harzianum had been grown. This was aimed at testing for the
possible presence of compounds released by T. harzianum into the media, which might prove to be
effective in curtailing/eliminating the axis-associated microflora. Among the different treatments
tested, the best method was utilised to decontaminate the embryonic axes prior to minimal-growth
storage (hydrated axes encapsulated in alginate gel ‘beads’).
Penicillium spp. were predominant among the different fungi isolated, which included Fusarium spp.,
Rhizopus spp., Aspergillus niger and Aspergillus flavus. Co-culturing with T. harzianum for 24 h was
successful in terms of the survival of the embryonic axes, although the roots produced were shorter
than when axes were cultured alone, but had no effect in eliminating the contaminants. Longer periods
of co-culturing with T. harzianum affected the germination of the embryonic axes of T. dregeana
compared with axes germinated in the absence of the biocontrol agent (control). The culture filtrate
negatively affected germination of the T. dregeana embryonic axes, although it was effective against
the associated contaminants. Nipastat was effective in reducing the contamination, and, depending on
the concentration, did not affect germination adversely. Medi-Chlor was highly effective in
eliminating all the contaminants from axes in vitro. Both these treatments were therefore used to
decontaminate axes before minimal-growth storage. All the NaDCC-treated, encapsulated axes
examined after 14 d hydrated storage [in Magenta boxes] and after 14-42 d in polythene bags
survived; however the axes stored in aluminium foil-lined bags and Eppendorf tubes soon lost
viability.
The recommendation is therefore made that the decontamination treatment based on use of NaDCC
(or other preparations of sodium dichloro-isocyanurate) be tested on embryonic axes of a range of
recalcitrant-seeded species, and, if successful, the procedure be introduced into cryopreservation
protocols. The use of NaDCC has emerged as a promising method of eliminating contaminating
microflora which otherwise compromise in vitro procedures, from seed-derived explants.
Furthermore, containment of decontaminated encapsulated axes in sealed polythene bags offers an
apparently ideal means of temporary storage and dissemination. The results should find considerable
applicability when excised embryonic axes representing the germplasm of recalcitrant seeds, are cryoconserved. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2013.
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Germinação e vigor de sementes de soja em função da disponibilidade hídrica do solo e presença de Phomopsis sojaeSimoni, Fabiana De [UNESP] 29 June 2007 (has links) (PDF)
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simoni_f_dr_jabo.pdf: 283626 bytes, checksum: 7040ccc9750e133445c4d78471b87dd1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo da presente pesquisa foi verificar o efeito da disponibilidade hídrica e de Phomopsis sojae na germinação de sementes de soja. Para caracterização das qualidades fisiológica e sanitária das sementes foram usados os seguintes testes: padrão de germinação e de vigor (envelhecimento acelerado, condutividade elétrica e massa seca das plântulas) e “blotter test”; além disso, determinou-se o teor de água, antes e após o envelhecimento. Para o estudo da emergência com disponibilidade hídrica, foram considerados três tratamentos: 60% (H1), 40% (H2) e 20% (H3) de sua capacidade de retenção de água. As sementes foram inoculadas artificialmente com Phomopsis sojae por contato dessas com o fungo por um período de 32 horas, posteriormente foram semeadas em caixas plásticas para a condução do teste de emergência com disponibilidade hídrica. A semeadura das quatro variedades (MSoy 8400, MSoy 8200, Embrapa 48 e Paraíso) combinadas com os três tratamentos de disponibilidade hídrica e o fungo, constituíram 24 tratamentos com quatro repetições. Cada caixa recebeu 50 sementes, essas foram mantidas em ambiente de laboratório. A avaliação da emergência das plântulas foi feita aos 10 dias após a semeadura e, ao final desse período, procedeu-se a avaliação da massa seca de plântulas de soja. Para o estudo da disponibilidade hídrica em plântulas de soja e os níveis de inoculação das sementes com P. sojae foram considerados 18 tratamentos (3 disponibilidades hídricas: 50% (H1), 40% (H2) e 30% (H3) de sua capacidade de retenção de água x 6 níveis de sementes inoculadas (0, 5, 10, 20, 40 e 60%). O período de inoculação das sementes foi o mesmo utilizado anteriormente... / The objective of the present research was to verify the effect of water availability and Phomopsis sojae in the germination of soybean seeds. For characterization of physiological and sanitary qualities of the seeds the following tests were used: germination and vigor (accelerated aging, bulk electric conductivity and dry mass of seedlings) and blotter test ; besides, it was determined the water content, before and after the aging. For the study of the emergence with water availability, three treatments were considered: 60% (H1), 40% (H2) and 20% (H3) of its water retention capacity. The seeds were artificially inoculated with Phomopsis sojae by contact with the fungi for a period of 32 hours, laterly they were sowed in plastic boxes for the emergence test with water availability. Four varieties (MSoy 8400, MSoy 8200, Embrapa 48 and Paradise) were seeded combined with three levels of water availability and the fungi, constituted 24 treatments with four replications. Each box received 50 seeds, these were maintained in laboratory. The evaluation of the seedlings emergence was made in 10th day after seeding and at the end of that period was made the evaluation of the soybean seedlings dry mass. For the study of the water availability in soybean seedlings and the levels of inoculation of the seeds with P. sojae were considered 18 treatments (3 water availability: 50% (H1), 40% (H2) and 30% (H3) of its water retention capacity x 6 levels of inoculated seeds (0, 5, 10, 20, 40 and 60%). The period of the seeds inoculation was the same used previously. The evaluation of the seedlings emergence was made in 10th day after the seeding and at the end of that period was made the evaluation of the soybean seedlings dry mass. The obtained results allowed to conclude that the relationship between the emergence of soybean seedlings in soil and Phomopsis sojae varied with the level of water...(Complete abstract, click electronic access below)
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Etapas do beneficiamento na qualidade física, fisiológica e sanitária de sementes de capim-colonião / Effects of processing phases in the physical, physiological and sanitary quality of guinea grass seedsMelo, Lilian Faria de [UNESP] 08 June 2016 (has links)
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Previous issue date: 2016-06-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As sementes de gramíneas forrageiras recebidas pelas empresas após a colheita contêm impurezas cuja remoção é realizada por máquinas de beneficiamento. Este procedimento é necessário para a obtenção de sementes dentro dos padrões de qualidade para a comercialização e a semeadura. O objetivo deste trabalho foi avaliar o efeito das etapas de beneficiamento na qualidade física, fisiológica e sanitária de sementes de Panicum maximum cultivares Tanzânia, Mombaça e Massai. As sementes foram amostradas antes do processamento e após a saída da máquina de ar e peneiras (descarga das peneiras superior, intermediária e fundo), primeira mesa gravitacional (deriva, descarga superior e intermediária), máquina tratadora e segunda mesa gravitacional (descarga superior, intermediária e inferior). As sementes foram avaliadas quanto ao teor de água, qualidade física (pureza e peso de mil sementes), fisiológica (germinação, primeira contagem, classificação do vigor de plântulas, envelhecimento acelerado, comprimento de plântulas, emergência de plântulas em campo e índice de velocidade de emergência) e sanitária (Blotter Test). O beneficiamento de sementes na máquina de ar e peneiras e mesa gravitacional é eficiente para o aprimoramento da qualidade física dos lotes das três cultivares de Panicum maximum e fisiológica somente para as cultivares Mombaça e Massai. O tratamento das sementes de Panicum maximum cultivar Tanzânia com tinta corante reduz a velocidade de emergência de plântulas em campo. Tendo como referência os padrões de comercialização nacional de sementes, o beneficiamento é necessário somente para o lote da cultivar Mombaça, para atender aos requisitos de pureza. Os fungos encontrados nas sementes de Panicum maximum cultivares Tanzânia, Mombaça e Massai durante o beneficiamento foram: Alternaria sp., Aspergillus sp., Cercospora sp., Cladosporium sp., Curvularia sp., Epicoccum sp., Fusarium sp., Helminthosporium sp., Penicillium sp., Phoma sp. e Rhizopus sp.. Foi encontrado também para a cultivares Tanzânia e Mombaça o fungo Rhizoctonia sp., Microspora sp., Pyrenochaeta sp. para as cultivares Mombaça e Massai, e Nigrospora sp. somente para a cultivar Massai. Esses fungos encontram-se alojados interna e externamente nas sementes e podem ser disseminados pelas máquinas de beneficiamento. Algumas etapas de beneficiamento são capazes de reduzir parcialmente a incidência de alguns fungos. / The harvested seeds upon being received by the forage grass company, are found to be contaminated with impurities which are removable by processing machines. This procedure is necessary to produce seeds of a quality level within standards established for commercialization and sowing purposes The objective of this project was to evaluate the effects of processing phases on the physical, physiological and physiological quality of guinea grass cv. Tânzania, Mombaça and Massai (Panicum maximum) seeds for commercialization purposes. Seeds were sampled before processing and after leaving the air and screen machine (upper and intermediary screens and bottom); first gravity table (drift, upper and intermediate spouts); treating machine; second gravity table (upper, intermediate, and lower spouts). Seeds were evaluated as to water content, physical quality (purity and 1,000 seeds weight) and physiological (germination, first count of germination, seedling vigor classification, accelerated aging, primary root length, aerial part length, seedling emergence in the field, and speed of emergence index). The sanitary test was conducted according to the filter paper method (Blotter test) with the seeds being superficially disinfested. The processing of seeds in the air screen cleaner and gravity table is effective to improve the physical quality of batches of three cultivars of Panicum maximum and physiological only for Mombaça and Massai cultivars. Seed treatment with dye ink reduces the speed of emergence seedling field. With reference to the national marketing standards of seeds, processing is only necessary to cv. Mombaça to meet the purity requirements. Fungi found in the seeds of Panicum maximum cv. Tanzania, Mombaça and Massai during processing were Alternaria sp., Aspergillus sp., Cercospora sp., Cladosporium sp., Curvularia sp., Epicoccum sp., Fusarium sp., Helminthosporium sp., Penicillium sp., Phoma sp. and Rhizopus sp. It was also found for the cultivars Tanzania and Mombaça fungus Rhizoctonia sp., Microspora sp., Pyrenochaeta sp. for Mombaça and Massai cultivars and Nigrospora sp. only to cultivate Massai. These fungi are internal and externally housed in the seeds and are disseminated by the processing machines. Some processing steps are able to partially reduce the incidence of some fungi.
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Germinação e vigor de sementes de soja em função da disponibilidade hídrica do solo e presença de Phomopsis sojae /Simoni, Fabiana De January 2007 (has links)
Orientador: Rita de Cássia Panizzi / Banca: Juliana Altafin Galli / Banca: Terezinha de Jesus Deléo Rodrigues / Banca: Rubens Sader / Banca: Adriana Zanin Kronka / Resumo: O objetivo da presente pesquisa foi verificar o efeito da disponibilidade hídrica e de Phomopsis sojae na germinação de sementes de soja. Para caracterização das qualidades fisiológica e sanitária das sementes foram usados os seguintes testes: padrão de germinação e de vigor (envelhecimento acelerado, condutividade elétrica e massa seca das plântulas) e "blotter test"; além disso, determinou-se o teor de água, antes e após o envelhecimento. Para o estudo da emergência com disponibilidade hídrica, foram considerados três tratamentos: 60% (H1), 40% (H2) e 20% (H3) de sua capacidade de retenção de água. As sementes foram inoculadas artificialmente com Phomopsis sojae por contato dessas com o fungo por um período de 32 horas, posteriormente foram semeadas em caixas plásticas para a condução do teste de emergência com disponibilidade hídrica. A semeadura das quatro variedades (MSoy 8400, MSoy 8200, Embrapa 48 e Paraíso) combinadas com os três tratamentos de disponibilidade hídrica e o fungo, constituíram 24 tratamentos com quatro repetições. Cada caixa recebeu 50 sementes, essas foram mantidas em ambiente de laboratório. A avaliação da emergência das plântulas foi feita aos 10 dias após a semeadura e, ao final desse período, procedeu-se a avaliação da massa seca de plântulas de soja. Para o estudo da disponibilidade hídrica em plântulas de soja e os níveis de inoculação das sementes com P. sojae foram considerados 18 tratamentos (3 disponibilidades hídricas: 50% (H1), 40% (H2) e 30% (H3) de sua capacidade de retenção de água x 6 níveis de sementes inoculadas (0, 5, 10, 20, 40 e 60%). O período de inoculação das sementes foi o mesmo utilizado anteriormente...(Resumo completo clicar acesso eletrônico abaixo) / Abstract: The objective of the present research was to verify the effect of water availability and Phomopsis sojae in the germination of soybean seeds. For characterization of physiological and sanitary qualities of the seeds the following tests were used: germination and vigor (accelerated aging, bulk electric conductivity and dry mass of seedlings) and " blotter test "; besides, it was determined the water content, before and after the aging. For the study of the emergence with water availability, three treatments were considered: 60% (H1), 40% (H2) and 20% (H3) of its water retention capacity. The seeds were artificially inoculated with Phomopsis sojae by contact with the fungi for a period of 32 hours, laterly they were sowed in plastic boxes for the emergence test with water availability. Four varieties (MSoy 8400, MSoy 8200, Embrapa 48 and Paradise) were seeded combined with three levels of water availability and the fungi, constituted 24 treatments with four replications. Each box received 50 seeds, these were maintained in laboratory. The evaluation of the seedlings emergence was made in 10th day after seeding and at the end of that period was made the evaluation of the soybean seedlings dry mass. For the study of the water availability in soybean seedlings and the levels of inoculation of the seeds with P. sojae were considered 18 treatments (3 water availability: 50% (H1), 40% (H2) and 30% (H3) of its water retention capacity x 6 levels of inoculated seeds (0, 5, 10, 20, 40 and 60%). The period of the seeds inoculation was the same used previously. The evaluation of the seedlings emergence was made in 10th day after the seeding and at the end of that period was made the evaluation of the soybean seedlings dry mass. The obtained results allowed to conclude that the relationship between the emergence of soybean seedlings in soil and Phomopsis sojae varied with the level of water...(Complete abstract, click electronic access below) / Doutor
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Controle alternativo de Fusarium spp. em sementes de milho / Alternative control of Fusarium spp. in maize seedsSouza, Nadja Glaucia de Melo 30 March 2017 (has links)
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Previous issue date: 2017-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Maize seeds are susceptible to Fusarium spp., which cause rotting, damping off and corn kernel contamination by mycotoxins. Plants produce antimicrobial compounds that can be extracted and used as an alternative method in the management of diseases. The objective of this work was to obtain an alternative product, through the use of vegetal extracts associated with powders (rock powder, kaolin and ash) for the control of Fusarium spp. associated with maize seeds. For this, were evaluated the fungitoxicity of extracts of fruits of chilli pepper, eucalyptus leaves, black pepper fruits and neem leaves to Fusarium spp.; and the effect of the extracts on the germination of maize seeds. The tested plant extracts are fungitoxic to Fusarium spp. causing total inhibition of the growth of the pathogens from the concentration of 5%. The treatment of the seeds with the extracts (20%) did not cause decrease in germination, and the extract of chilli pepper promoted the germination of the seeds. The black pepper extract (10%) had fungitoxic effect to F. verticillioides (F159 and F311) in maize cv. Sertanejo. The extracts tested (10% and 20%) did not inhibit F. oxysporum (F01) in maize cv. Sertanejo. Black pepper extract + rock powder, solvent + rock powder and solvent + kaolin accelerated the germination of maize cv. Sertanejo. All formulations tested decreased the incidence of F. verticillioides F311 in maize var. Sertanejo. Extract of black pepper + rock powder and black pepper extract had a positive effect on the control of damping off caused by Fusarium spp., and ind in the seedling development. It is concluded that the alternative product formulated with black pepper extract + rock powder and the black pepper extract have potentiality to be used in the alternative control of Fusarium spp. in maize seeds. / Sementes de milho são suscetíveis a Fusarium spp., que causam o apodrecimento, tombamento das plântulas e a contaminação dos grãos por micotoxinas. Plantas produzem compostos antimicrobianos que podem ser extraídos e utilizados como método alternativo no manejo de doenças. O objetivo do trabalho foi obter um produto alternativo, por meio da utilização de extratos vegetais associados a pós (pó de rocha, caulim e cinza) para o controle de Fusarium spp. associados às sementes de milho. Para tanto, foi avaliada a fungitoxicidade de extratos de frutos de pimenta malagueta, folhas de eucalipto, frutos de pimenta do reino e folhas de neem a Fusarium spp.; e o efeito dos extratos na germinação de sementes de milho. Os extratos vegetais testados são fungitóxicos a Fusarium spp., causando inibição total do crescimento dos patógenos a partir da concentração de 5%. O tratamento das sementes com os extratos (20%) não causou diminuição da germinação, sendo que o extrato de pimenta malagueta promoveu a germinação das sementes. O extrato de pimenta do reino (10%) teve efeito fungitóxico a F. verticillioides (F159 e F311) em sementes de milho cv. Sertanejo. Os extratos testados (10% e 20%) não inibiram F. oxysporum (F01) nas sementes de milho cv. Sertanejo. Extrato de pimenta do reino + pó de rocha, solvente + pó de rocha e solvente + caulim aceleraram a germinação das sementes de milho cv. Sertanejo. Todas as formulações testadas diminuíram a incidência de F. verticillioides F311 nas sementes de milho var. Sertanejo. Extrato de pimenta do reino + pó de rocha e extrato de pimenta do reino tiveram efeito positivo no controle do tombamento causado por Fusarium spp.; e na promoção de desenvolvimento das plântulas. Conclui-se que o produto alternativo formulado com extrato de pimenta do reino + pó de rocha e o extrato de pimenta do reino têm potencialidade para serem utilizados no controle alternativo de Fusarium spp. em sementes de milho.
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