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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Disponibilidade do nitrogênio no solo e produtividade da cana-de-açúcar em função da rotação de culturas / Availability of nitrogen in soil and productivity of sugarcane in function of crop rotation

Tenelli, Sarah 13 September 2016 (has links)
A adoção da rotação de culturas com leguminosas em áreas de implantação e reforma de canaviais é uma estratégia promissora para recuperação e manutenção da fertilidade do solo, e tem potencial no aproveitamento do N para as soqueiras. A análise mais detalhada do comportamento do N no solo durante o ano agrícola e dos parâmetros de produção em locais que possuem solo e clima contrastantes, permitem aprimorar o manejo da adubação nitrogenada da cana-de-açúcar. As hipóteses deste trabalho são (1) a rotação de culturas irá aumentar a disponibilidade de N no solo, a qual suprirá parte da demanda do N das soqueiras subsequentes e (2) a rotação de culturas promoverá redução da resposta das soqueiras à adubação nitrogenada. Objetivou-se avaliar o efeito da rotação de culturas nas transformações do N no solo (N mineral, N-ISNT e N e C da biomassa microbiana) e na produtividade da primeira soqueira. Os experimentos foram instalados em quatro regiões representativas de cultivo de cana-de-açúcar na região Centro Sul do Brasil: Quatá/SP (Local A); Iracemápolis/SP (Local B); Chapadão do Céu/GO (Local C) e Quirinópolis/GO (Local D). Em cada local, foi instalado um experimento em esquema de parcelas subdivididas no delineamento blocos ao acaso com quatro repetições, em áreas submetidas (com rotação) ou não (sem rotação) ao plantio de leguminosa do gênero crotalária. Após a colheita da cana planta, foram implantados os seguintes tratamentos: 60, 120 e 180 kg ha-1 de N e um controle (sem N), aplicados superficialmente sobre a palhada. Foram realizadas três amostragens para determinação do conteúdo de N mineral, N-ISNT e C e N da biomassa microbiana. Entre 150 a 180 dias após a colheita da cana-planta, foram realizadas avaliações de perfilhamento e índice SPAD. Na colheita, avaliou-se matéria seca da parte aérea, produtividade e atributos tecnológicos. Os resultados demonstraram que a mineralização dos resíduos da crotalária influenciaram a dinâmica do C e N e os reservatórios de N no perfil do solo ao longo do ciclo da primeira soqueira, com destaque para o solo de textura média (Local A). Apesar da rotação de culturas ter modificado o conteúdo de N mineral, N-ISNT, e aumentado o perfilhamento e índice SPAD no local A, somente nos solos argilosos (Locais C e D), a rotação aumentou a produtividade da soqueira. A hipótese de que a rotação de culturas reduz a demanda de fertilizantes nitrogenados não foi aceita; houve resposta à adubação nitrogenada nos quatro locais, independentemente da rotação de culturas. Porém, a rotação demonstrou potencial em aumentar a produção de biomassa com manutenção da dose de N. Esta pesquisa demonstrou a viabilidade de rotação de culturas em solos argilosos com elevado conteúdo de C e N total, com potencial de aumentar a produtividade do canavial, porém sem reduzir a demanda de adubação nitrogenada. / The adoption of crop rotation with sugarcane is a promising strategy for the recovery and maintenance of soil fertility, and it shows potential in the use of N to the sugarcane ratoon. A more detailed analysis of the transformations N in soil during the agricultural year and production parameters in sites that have contrasting soil texture and climate, allows to improve management of N fertilization for sugarcane. The hypothesis of this work are (1) crop rotation will increase soil N availability, which will satisfy part of N requirements of sugarcane ratoon and (2) crop rotation will reduce the sugarcane ratoon response to N fertilization. The objective was to evaluate the effects of sunn hemp rotation in the transformations of N in soil (mineral N content, ISNT-N and microbial biomass C and N) and sugarcane ratoon yield. The field trials were installed in four representative regions of cultivation of sugarcane in Brazil: Quatá/SP (Site A); Iracemápolis/SP (Site B); Chapadão do Céu/GO (Site C) e Quirinópolis/GO (Site D). At each site, a field trial was installed in split plot in a randomized block experimental design with four replications, in areas sowed (rotation) and not sowed (no rotation) with sunn hemp. After the harvest of cane-plant, the following treatments were applied: 60, 120 and 180 kg ha-1 of N and a control (without N) over the straw. Three sampling were performed to determine the soil inorganic N content, ISNT-N, C and N of microbial biomass. Between 150 to 180 days after the harvest of the cane-plant, tillering was counted and SPAD index was measured. At harvest of the sugarcane ratoon, biometric parameters, yield and quality parameters were evaluated. The results showed that mineralization of residues of sunn hemp influenced the dynamics of C and N and N content in the soil profile throughout the cycle of the sugarcane ratoon, with emphasis on medium-textured soil (Site A). Despite crop rotation has modified mineral N stocks, ISNT-N, and increased tillering and SPAD index in site A, crop rotation only increased the sugarcane ratoon yield on clay soils (Sites C and D). The hypothesis that crop rotation reduces N-fertilizer requirement was not accepted; there was response to N fertilization in four sites, regardless of crop rotation. However, the rotation showed potential in increase biomass production with maintenance of N rate. This research demonstrated the viability of crop rotation in clay soils with high total C and N content, with potential to increase sugarcane yield, but without reducing N-fertilizer requirement.
262

Avaliação da qualidade microbiológica, contagem de Pseudomonas spp, e sua importância durante a obtenção e armazenamento de leite cru refrigerado no período de seca e chuva / Microbiological quality evaluation, Pseudomonas spp. count and its importance during the collection and storage of refrigerated raw milk in the dry and rain periods

Capodifoglio, Eduardo 20 November 2015 (has links)
Na propriedade rural, onde o leite cru refrigerado fica armazenado até a captação pelo caminhão tanque em coleta a granel, o mesmo é mantido a temperatura de refrigeração entre 1 a 4ºC por longos períodos (até 96 horas), os microrganismos psicrotróficos encontram condições favoráveis para sua multiplicação, produzindo enzimas proteolíticas e lipolíticas termotolerantes, podendo provocar alterações indesejáveis no leite e nos seus derivados. Quando estes microrganismos estão presentes em elevadas populações, pode ser indicativo de baixa qualidade do leite e insatisfatória condições sanitárias para o processamento. Devido a necessidade da melhora da qualidade dos produtos lácteos, objetivou-se a execução desta pesquisa realizando levantamentos sobre o cumprimento dos padrões microbiológicos exigidos pela atual legislação brasileira IN 62 (BRASIL, 2011), pesquisas sobre os microrganismos psicrotróficos, Pseudomonas spp. e produção de enzimas proteolítica e lipolítica por Pseudomonas spp. As coletas foram realizadas em 10 propriedades do Estado de São Paulo na Regional Agrícola do Escritório de Desenvolvimento Rural - EDR Limeira - SP, sendo, 5 propriedades com ordenha manual e 5 propriedades com ordenha mecânica, nos períodos de chuva e seca e em vários pontos durante a obtenção do leite cru refrigerado e também do leite com intervalo de 24 horas até a captação deste leite pelo caminhão. As médias das populações dos microrganismos mesófilos na ordenha manual, foi diferente estatisticamente significativo no leite recém ordenhado (1,52×106 UFC.mL-1) para o leite com 24 horas de armazenamento (2,67×107 UFC.mL-1) no período chuvoso, e na ordenha mecânica, o encontrado foi uma diferença estatisticamente significativa no leite recém ordenhado (3,87×106 UFC.mL-1) para o leite com 24 horas de armazenamento (9,82×108 UFC.mL-1) também no período chuvoso. Nas populações dos microrganismos psicrotróficos, suas médias diferiram estatisticamente na ordenha manual no período da chuva no leite recém ordenhado (1,48×104 UFC.mL-1) para o leite com 48 horas de armazenamento (1,49×105 UFC.mL-1) e na ordenha mecânica, o leite recém ordenhado (8,74×103 UFC.mL-1), com 24 horas de armazenamento (4,33×104 UFC.mL-1) não diferiram entre si e foram diferentes estatisticamente do leite com 48 horas de armazenamento (3,46×105 UFC.mL-1) apresentaram valor elevado, principalmente quando o leite cru refrigerado permanece por longos períodos de armazenamento na propriedade rural, que pode ser um sério fator de comprometimento pela produção de lipases ou proteases principalmente pelas Pseudomonas spp. onde em todos os pontos amostrados foram isolados este microrganismo produzindo enzimas (lipase e/ou protease). A maior porcentagem de atividade lipolítica foi verificada no período seco, já a maior porcentagem de atividade proteolítica foi verificada no período chuvoso. Contudo, deve-se intensificar as medidas de autocontrole para minimizar os efeitos dos microrganismos mesófilos e psicrotróficos sobre a qualidade do leite cru refrigerado e, consequentemente, de seus derivados. / On the farm, where the cold raw milk is stored until the tank truck collects it in bulk, it is kept at refrigeration temperature between 1 and 4°C for extended periods (96 hours), the psychrotrophic microorganisms find favorable conditions for their multiplication, producing proteolytic and lipolytic thermotolerant enzymes, it may cause undesirable changes in milk and its derivatives. When these microorganisms are present in a large population, it can be an indicative of low quality milk and unsatisfactory sanitary conditions for its processing. Due to the need of improving the quality of dairy products, this research was carried out with surveys about fullfilment of microbiological standards required by current Brazilian law IN 62 (BRAZIL, 2011), researches on psychrotrophic microorganisms, Pseudomonas spp. and production of proteolytic and lipolytic enzymes by Pseudomonas spp. Samples were collected in 10 farms in the state of São Paulo in the Regional Agrícola do Escritório de Desenvolvimento Rural - EDR in Limeira - SP, 5 farms with manual milking and 5 farms with mechanical milking; during the rainy and dry periods and in several points during the obtaining of refrigerated raw milk and also milk with a 24-hour-interval before the collection of this milk by the truck. The averages of the mesophilic population in the manual milking were different, statistically significant between the newly expressed milk (1,52×106 UFC.mL-1) and 24 hour-storage milk (2,67×107 UFC.mL-1) in the rainy season, and during mechanical milking, what was found was a statistically significant difference between the newly expressed milk (3,87×106 UFC.mL-1) and 24-hour-storage milk (9,82×108 UFC.mL-1, also in the rainy season. In the populations of psychrotropic microorganisms, the averages statistically differed in manual milking during the period of rain between the newly expressed milk (1,48×104 UFC.mL-1) and 48-hour-storage milk (1,49×105 UFC.mL-1); and during the mechanical milking, newly expressed milk (8,74×103 UFC.mL-1) and 24-hour-storage (4,33×104 UFC.mL-1); were not different and were statistically different from 48-hour-storage milk (3,46×105 UFC.mL-1), they present high value, especially when refrigerated raw milk remains for long storage periods on the farm, which can be a serious impairment factor for the production of lipases and proteases mainly by Pseudomonas spp. where in all the sampling sites these microorganisms were isolated producing enzymes (lipase and/or protease). The highest percentage of lipolytic activity was observed in the dry season; the highest percentage of proteolytic activity was observed during the rainy season. However, the self-control measurementsshould be intensified to minimize the effects of mesophilic and psychrotrophic microorganisms on the quality of refrigerated raw milk and, consequently, its derivatives.
263

Pesquisa de genes codificadores de adesinas em Staphylococcus spp. isolados de mastite bovina / Search for adhesins-encoding genes in Staphylococcus spp. isolated from bovine mastitis

Zuniga, Eveline 05 February 2013 (has links)
No universo da pecuária leiteira, a mastite representa um importante desafio, sendo responsável por perdas econômicas consideráveis relacionadas principalmente com redução na produção de leite. O gênero Staphylococcus assume elevada importância como agente etiológico das mastites devido à sua ampla distribuição e freqüência de ocorrência. Foram coletadas amostras de leite de fêmeas bovinas com mastite subclínica para exames microbiológicos e contagem de células somáticas (CCS). Após o isolamento e identificação dos micro-organismos, as amostras positivas foram submetidas a análises das medianas das CCS, testes de susceptibilidade \"in vitro\" frente a diferentes antimicrobianos, assim como pesquisa de genes codificadores das adesinas - genes que codificam para proteína ligadora de colágeno (cna), proteína ligadora de laminina (eno), proteína ligadora de elastina (ebp), proteína ligadora de fibrinogênio (fib), proteína A ligadora de fibronectina (fnbA), proteína B ligadora de fibronectina (fnbB) e proteína associada à formação de biofilme (bap), por meio da Reação em Cadeia da Polimerase (PCR). De acordo com os achados do presente estudo, dentre as bactérias do gênero Staphylococcus isoladas, os S. aureus foram verificados com maior freqüência, seguido por Staphylococcus coagulase-negativos - S. intermedius, S. chromogens e S. warneri. Com respeito às medianas das CCS, o gênero Streptococcus spp. apresentou o maior valor. O perfil de sensibilidade e resistência aos antimicrobianos testados foi semelhante entre as espécies de Staphylococcus coagulase-positivos e negativos, sendo os antimicrobianos cefalexina, cefalotina e ceftiofur os que apresentaram maior frequência de sensibilidade, e penicilina, amoxicilina e ampicilina os que apresentaram maior resistência. Com exceção do (fnbA), todos os outros fatores de virulência estudados foram detectados, sendo os genes eno, fib e a associação dos genes \"eno/fib/bap\" os mais freqüentemente detectados. Nas amostras coletadas dos tanques de refrigeração não foram detectadas todas as espécies de Staphylococcus spp. isoladas dos quartos mamários. Tais informações acerca do assunto permitem o desenvolvimento de estratégias mais eficientes de tratamento e controle desta enfermidade, possibilitando o aumento da produtividade leiteira. / In the world of dairy cattle, mastitis is a major challenge, accounting for economic losses related mainly to reduction in milk production. The genus Staphylococcus assumes greater importance as a etiologic agent of mastitis due to its wide distribution and frequency of occurrence. Milk samples were collected from cows with subclinical mastitis to microbiological examinations and somatic cell count (SCC). After isolation and identification of microorganisms, positive samples were analyzed for the medians of SCC, tested for susceptibility \"in vitro\" against different antimicrobials and polymerase chain reaction will be used to search for genes encoding adhesins - genes that code for collagen-binding protein (cna), lamininbinding protein (eno), elastin-binding protein (ebp), fibrinogen-binding protein (fib), fibronectin-binding protein A (fnbA), fibronectin-binding protein B (fnbB) and protein associated with biofilm formation (bap). According to the findings of this study, among the bacteria of the genus Staphylococcus isolated, S. aureus were found most frequently, followed by coagulase-negative Staphylococcus - S. intermedius, S. chromogens and S. warneri. With respect to the medians of CCS, the genus Streptococcus spp. showed the highest. The profile of sensitivity and resistance to antimicrobials was similar among species of coagulase-positive and negative Staphylococcus, and antimicrobial cephalexin, cephalothin, and ceftiofur showed higher frequency sensitivity. Penicillin, amoxicillin and ampicillin showed the highest resistance. With the exception of (fnbA), all other virulence factors were detected, with genes eno, fib and the association of genes \"eno/fib/bap\" the most frequently detected. The samples collected from the cooling tanks were not detected all species of Staphylococcus spp. that were isolated from the mammary glands. Such information on the subject allow the development of more efficient strategies for treatment and control of this disease, allowing for increased milk production.
264

Caracterização de amostras de Erysipelothrix spp. isoladas de suínos nos últimos 30 anos / Characterization of Erysipelothrix spp. strains isolated from swine in last 30 years

Coutinho, Tania Alen 24 June 2010 (has links)
Erysipelothrix rhusiopathiae é um importante patógeno em suinocultura e apesar do uso freqüente de vacinas contra o mesmo na maior parte das propriedades produtoras do país, a ocorrência de quadros clínicos da infecção tem sido amplamente observada e diagnosticada. Tendo em vista o ressurgimento deste agente como causa de prejuízos econômicos para a indústria suinícola nacional e seu potencial risco à saúde pública, este estudo teve como objetivo caracterizar 151 amostras de Erysipelothrix spp. isoladas de suínos nos útlimos 30 anos por meio de sorotipagem, determinação da susceptibilidade antimicrobiana, AFLP e PFGE. Dentre os 151 isolados, 139 foram classificados em 18 sorotipos diferentes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 e 25), sendo que o sorotipo 2b foi o mais freqüente. Os perfis de susceptibilidade antimicrobiana foram muito semelhantes entre os isolados, o que impossibilitou a subtipagem dos isolados de Erysipelothrix spp. pelos testes de sensibilidade. Dentre os primers testados no AFLP, o HI-G foi o mais adequado à tipagem molecular de Erysipelothrix spp. Apesar do AFLP/HI-G e da PFGE apresentarem o mesmo índice discriminatório (0,98), a PFGE apresentou melhor relação com os dados epidemiológicos que o AFLP/HI-G, tendo em conta os agrupamentos por ela gerados. Independente da técnica molecular empregada, não foi observado a discriminação entre isolados recentes e históricos, bem como um padrão epidemiológico fixo de agrupamento dos mesmos. Contudo, o AFLP/HI-G pode ser uma alternativa interessante para diferenciar as espécies de Erysipelothrix, assim como a PFGE tem grande potencial para agrupar isolados deste gênero de acordo com os sorotipos. / Erysipelothrix rhusiopathiae is an important pathogen in swine production and even with the frequent use of vaccines against it in most of Brazilian pig farms, the occurrence of clinical manifestations of its infection has been widely observed and diagnosed. Given the resurgence of this agent as a cause of economic losses to the national pig industry and its potential risk to public health, this study aimed to characterize 151 samples of Erysipelothrix spp. isolated from swine in last 30 years by serotyping, determination of antimicrobial susceptibility, AFLP and PFGE. Among the 151 isolates, 139 were classified in 18 different serotypes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 and 25) and serotype 2b was the most frequent. The susceptibility profiles were very similar among the isolates, which precluded the subtyping of Erysipelothrix spp. isolates by sensitivity tests. Among the primers tested in AFLP, the HI-G was the most suitable for molecular typing of Erysipelothrix spp. Despite AFLP/HI-G and PFGE provided the same discriminatory index (0.98), PFGE presented better relationship with epidemiological data than AFLP/HI-G, given the types of groups generated by it. Regardless of the molecular technique employed, there was no discrimination between recent and historical isolates as well as a fixed epidemiological pattern of grouping them. Nevertheless AFLP/HI-G could be an interesting alternative for Erysipelothrix species discrimination, even as PFGE has a good potential to diferenciate this genus according to serotypes.
265

Estudo do efeito de microrganismos probióticos sobre Eimeria acervulina (Tyzzer, 1929) em frangos de corte / Study of the effect of probiotic microorganisms on Eimeria acervulina (Tyzzer, 1929) in broilers

Freitas, Wagner Luiz da Costa 19 August 2011 (has links)
No presente trabalho avaliou-se o efeito antiparasitário de uma preparação probiótica constituída por quatro espécies de lactobacilos, L. casei ATCC 7469, L. plantarum ATCC 8014, L. fermentum ATCC 9338 e L. acidophillus ATCC 4536, no tratamento da eimeriose aviária causada por Eimeria acervulina. Para tanto, foram utilizados 120 animais, da espécie Gallus gallus, machos, com 14 dias de idade, distribuídos em seis grupos, sendo o Grupo 1 constituído por animais tratados apenas com água e ração (controle negativo); Grupo 2 constituído por animais que receberam diariamente uma dose da preparação probiótica contendo 1x108 UFC/mL; Grupo 3 constituído por animais infectados experimentalmente com 2x105 oocistos esporulados de Eimeria acervulina (controle positivo) e Grupo 4 onde os animais receberam diariamente uma dose da preparação probiótica contendo 1x108 UFC/mL durante o período do experimento e após 7 dias do início do tratamento, foram infectados com 2x105 oocistos esporulados de E. acervulina; no Grupo 5 os animais foram infectados com 2x105 oocistos esporulados de E. acervulina e paralelamente receberam uma dose diária da preparação probiótica em estudo contendo 1x108 UFC/mL; no Grupo 6 os animais foram infectados com 2x105 oocistos esporulados de E. acervulina e após o surgimento dos sinais clínicos da infecção passaram a receber diariamente uma dose da preparação probiótica contendo 1x108 UFC/mL, até o final do experimento. Durante 28 dias, semanalmente, amostras de sangue e fezes foram coletadas para determinação de OoPG, testes bioquímicos e parâmetros zootécnicos. Exames de fezes foram realizados diariamente para se determinar os períodos pré-patente e patente do parasita, bem como o efeito da preparação probiótica no combate a infecção. Os resultados demonstraram que a preparação probiótica em estudo reduziu a infecção intestinal causada por Eimeria acervulina, contribuindo para o bem estar animal. Referente aos parâmetros bioquímicos verificou-se efeito significativo sobre o perfil lipídico no 4º dia pós infecção, não sendo observado diferenças significativas para os demais parâmetros. No tocante ao desempenho zootécnico, verificou-se que a preparação probiótica não resultou em diferenças significativas em relação ao ganho de peso, eficiência e conversão alimentar dos animais avaliados. / This study evaluated the antiparasitic effect of a probiotic preparation which consisted of four species of lactobacilli (Lactobacillus casei ATCC 7469, L. plantarum ATCC 8014, L. fermentum ATCC 9338 and L. acidophilus ATCC 4536) in the treatment of eimeriosis in broilers caused by Eimeria acervulina. Therefore, during 28 days, 120 animals of Gallus gallus species, males, 14 days old, were distributed in six groups, as follow: Group 1 the animals received only feed and water \"ad libidum\" (negative control); Group 2 consisted of animals that received a daily dose of probiotic preparation which contained 1x108 CFU/mL; Group 3 the animals were experimentally infected with 2x105 oocysts of Eimeria acervulina (positive control); Group 4 the birds received a daily dose of probiotic preparation containing 1x108 CFU / mL during the experiment and after 7 days of the treatment beginning, these animals were infected with 2x105 oocysts of E. acervulina; Group 5 was composed by animals that were infected with 2x105 oocysts of the parasite and simultaneously received a daily dose of probiotic preparation containing 1x108 CFU / ml, Group 6 the animals were infected with 2x105 oocysts of E. acervulina and after clinical signs of infection were noticed, the birds were treated daily with a dose of the probiotic preparation containing 1x108 CFU / mL until the end of the experiment. During 28 days six blood and feces samples were collected and parameters such as oocyst elimination, histopathological, and biochemical were evaluated. Stool examinations were performed daily to determine the parasite prepatent and patent periods, and the probiotic effect on the infection. The results showed that the probiotic preparation under study reduced the intestinal infection caused by Eimeria acervulina, contributing to animal welfare. Regarding the biochemical parameters there was a significant effect on the lipid profile on the 4th day after infection, and no significant differences were observed for the other parameters. With regard to zootechnical performance, it was found that the probiotic preparation resulted in no significant differences in weight gain, and in feed conversion efficiency.
266

Estratégias de manejo químico para controle de Mucuna aterrima, Ricinus communis, Merremia aegyptia, Ipomoea hederifolia e Ipomoea quamoclit e sua seletividade no plantio da cana-de-açúcar /

Bidóia, Vitor Simionato January 2019 (has links)
Orientador: Carlos Alberto Mathias Azania / Resumo: As espécies de Mucuna aterrima, Ricinus communis, Merremia aegyptia, Ipomoea hederifolia e Ipomoea quamoclit comumente infestam os canaviais brasileiros e seu manejo depende da integração de métodos e modalidades de aplicação de herbicidas. O objetivo da pesquisa foi de avaliar a seletividade e eficácia de herbicidas em programas de manejo com aplicações antes e após o plantio da cana-de-açúcar. O experimento foi conduzido no Brasil, município Ribeirão Preto, SP, em canavial cultivado em Latossolo Vermelho de textura argilosa, localizado sob clima Cwa de Koppen, entre janeiro/2018 a março/2019. O delineamento experimental foi em blocos casualisados com dez tratamentos em quatro repetições. As parcelas foram constituídas por cinco linhas de cana-de-açúcar com 5 m de comprimento e espaçadas de 1,5 m. As parcelas foram semeadas com as espécies de M. aterrima, R. communis, M. aegyptia, I. hederifolia e I. quamoclit, sempre antes da primeira aplicação de herbicida. Os tratamentos foram constituídos pela testemunha capinada (Tcapinada) e sem capina (Tpds), além de oito programas de manejo químico (P) constituídos por aplicações em plantio pré-incorporado (PPI), pré-emergência (PRE) e pós-emergência tardia das plantas daninhas e cultura após plantio (POS-t), conforme: P1- PRE (diuron + sulfentrazone); P2 -PPI (imazapyr) + PRE (diuron + sulfentrazone); P3 - PPI (amicarbazone) + PRE (diuron + sulfentrazone); P4 - PPI (sulfentrazone) + PRE (diuron + sulfentrazone); P5 - PRE (indaziflam... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The species of Mucuna aterrima, Ricinus communis, Merremia aegyptia, Ipomoea hederifolia and Ipomoea quamoclit commonly infest the Brazilian sugarcane plantations and their effective control depends on the integration of herbicide application methods and modalities. The objective of the research was to evaluate the selectivity and efficacy of herbicides in management programs with applications before and after sugarcane planting. The experiment was conducted in Ribeirão Preto, SP, Brazil, in a sugarcane planted in a clayey Red Latosol texture, located under Cwa of Koppen climate, from January/2018 to March/2019. The experimental delineation was performed in randomized blocks with ten treatments in four replicates. The plots were constituted by five lines of sugarcane with 5 m of length and spaced out of 1.5 m. The plots were planted with M. aterrima, R. communis, M. aegyptia, I. hederifolia and I. quamoclit, always before the first application of herbicide. The treatments consisted of the weed control (Tcapinada) and no weed (Tpds), as well as eight chemical management programs (P) consisting of pre-incorporated (PPI), pre-emergence (PRE) and late post-emergence applications weeds and post-planting crop (POS-t) as follows: P1- PRE (diuron + sulfentrazone); P2 -PPI (imazapyr) + PRE (diuron + sulfentrazone); P3 - PPI (amicarbazone) + PRE (diuron + sulfentrazone); P4 - PPI (sulfentrazone) + PRE (diuron + sulfentrazone); P5-PRE (indaziflam); P6-PPI (imazapyr) + PRE (indaziflam); ... (Complete abstract click electronic access below) / Mestre
267

Effet de différents paramètres de l'environnement sur le déterminisme biochimique d'exudats racinaires de crotalaria spp. : application à la nématorégulation en production végétale / Effect of different environmental parameters on the biochemical determinism of root exudates Crotalaria spp. : Application to crop production nématorégulation

L'Etang, Mylène 03 December 2012 (has links)
Dans le cadre de la promotion de systèmes de culture alternatifs à moindres intrants chimiques, des études sur l'introduction de plantes de service ayant vocation à réduire l'usage des pesticides et engrais azotés mobilisent un effort de recherche considérable. Dans le cadre de la production bananière pour laquelle la nuisibilité causée par les nématodes phytoparasites constitue l'une des principales contraintes, une des principales alternatives à l'utilisation de nématicides chimiques repose sur l'usage raisonné en rotation ou en association culturale de plantes de service à propriétés nématorégulatrices. Parmi les espèces candidates, celles du genre Crota/aria spp. ont largement été étudiées en raison de leur aptitude à contrôler les nématodes phytoparasites. Une méta-analyse révèle cependant que même si de nombreux auteurs s'accordent à reconnaître les propriétés allélopathiques des plantes de cette espèce, ils sont également enclins à reconnaître la forte variabilité d'expression de ces propriétés vis-à-vis du contrôle des nématodes selon les situations expérimentées. L'objectif de ce travail repose sur la compréhension du déterminisme biochimique des exsudats. La stratégie expérimentale mise en oeuvre a consisté à tester en conditions contrôlées le comportement biochimique des exsudats racinaires de deux espèces de crotalaires (C retusa, C spectabilis) et d'une espèce sensible, le bananier dessert (Musa spp.) en fonction i) de conditions biotiques variées -i.e. présence ou non de nématodes (Radopholus similis et Meloidogyne arenariaï, et présence ou non de mycorhizes-, ii) de conditions abiotiques contrastées -i.e. utilisation d'un sol naturel vs. substrat neutre, ajout ou non d'engrais chimique. La méthodologie innovante des «plantes à traire » (Brevet INRA) a été requise pour pouvoir travailler sur les exsudats racinaires des plantes conditionnées plutôt que sur des Iixiviats, comme réalisé dans des expérimentations antérieures.Les résultats obtenus en spectrophométrie visible montrent que la modification des conditions abiotiques affecte de manière importante les profils biochimiques des plantes étudiées. En présence du nématode 1..·1. arenaria les profils biochimiques des deux crotalaires sont également modifiés. Des biotests réalisés à l'aide des exsudats racinaires conditionnés au préalable par les modifications biotiques ont permis de démontrer l'effet nématostatique des crotalaires. Des analyses biochimiques en Ge-MS mettent en évidence de manière plus précise des molécules actives mises en jeu sous différentes modalités biotiques et abiotiques. Ces recherches, de portée générique, permettront de mieux comprendre les conditions de l'environnement qui régulent les profils biochimiques des exsudats racinaires des crotalaires et par extension, seront applicables aux recherches menées sur d'autres plantes de service candidates. Ceci aidera, à terme, à définir les conditions environnementales à réunir, pour orienter de manière optimale les effets allélopathiques dans une perspective de nématorégulation naturelle / As part of the promotion of alternative cropping systems at lower chemical inputs, studies on the introduction of cover crops designed to reduce the use of pesticides and nitrogen fertilizers mobilize a considerable research effort. Under banana production for which the hannfu1ness caused by plant-parasitic-nematodes is one ofthe main constraints, one of the main alternatives to the use ofchemical nematicides is based on the rational use in rotation or intercropping of cover rI crops to proteet crops from plant-parasitic-nematodes, Among the candidate species, the species from the genus of Crota/aria spp. have been widely studied because of their ability to control plant parasitic-nematodes. A meta-analysis reveals that although many authors agree allelopathic properties of these species, they are also likely to recognize the high variability of expression of these properties vis-àvis the control of nematodes according to the situations experieaced.. The objective of this woIk is focnsed on the onderstanding of the biochemical determinism of mot exudates onder environment biotic and abiotic variations. The experimental strategy was 10 test onder controlled conditions the biochemical behavior of mot exudates of two species of crotalarias (C retusa, C. spectabilis) and a susceptible species, the dessert banana crop (Musa spp.) with i) modification ofbiotic conditions -ie presence or absence of nematodes iMeloidogyne arenaria and Radopho/us similis), and presence or absence of mycorrhiza-ii) contrasting abiotic conditions -ie using a natural soil vs. neutral substrate, whether to add fertilizer. The innovative methodology of "milking plants" (patent INRA) was required in order to work on the root exudates of plants packed rather thanleachate, as done in previous experiments. The results obtained show that 'visible spectrophotometry changing abiotic conditions affect significantly the biochemical profiles of the studied plants. In the presence of nematode M. arenaria biochemical profiles of both crotalarias are also changed. Bioassays conducted using mot exudates conditioned in advance by biotic changes have demonstrated the effect of nématostatique crotalarias. Biochemical Ge-MS demonstrate more clearly active molecules that are involved in varions biotic and abiotic conditions. This research, generic scope, to better understand the environmental conditions that regulate biochemical profiles of mot exudates crotalarias and by extension, will apply to research on other plants service candidates. This will ultimately define the environmental conditions to meet, to guide optimal allelopathic effects from the perspective ofnatural nématorégulation
268

Survival of Spore forming bacteria during pasteurisation and anaerobic digestion in biogas plants.

Danielsson, Mari January 2006 (has links)
<p>ABSTRACT</p><p>Anaerobic digestion is one way of handling biowaste and generating energy in the form of methane, biogas.</p><p>This study shows that spore forming bacterias survive the process of pasteurisation and anaerobic digestion in biogas plants. It has also been established that both the nonpasteurised-and digestion- waste contains pathogen spore forming bacterias. Two Swedish full-scale</p><p>commercial biogas plants were sampled before pasteurisation, after pasteurisation and after digestion on 10 occasions with one week intervals. The samples were analysed quantitatively</p><p>and qualitatively, with biochemical methods, for Clostridium spp and Bacillus spp.</p><p>Polymerase Chain Reaction, a biomolecular method, was used for</p><p>C. chauvei analysis, with C. chauvei specific primers. For this analyse the biogas plants were sampled at 11 occasions.</p><p>Survival of pathogenic spore forming bacteria in digestion residue may be a health risk for both humans and animals. The digested residue may be used as fertiliser on arable land and the risk of contamination by pathogenic Clostridium spp and Bacillus spp is hard to assess, but can not be neglected.</p>
269

An investigation into the biology and medicinal properties of Eucomis species.

Taylor, Joslyn Leanda Susan. January 1999 (has links)
Eucomis (Family Hyacinthaceae) are deciduous geophytes with long, narrow leaves and erect, densely packed flower spikes. The bulbs are greatly valued in traditional medicine for the treatment a variety of ailments, and are thus heavily harvested for trade in South Africa's "muthi" markets. Eucomis species propagate relatively slowly from offsets and seed, and this, together with their over-utilization ethnopharmacologically, has led to their threatened status. This investigation focussed mainly on the study of the anti-inflammatory activity of plant extracts prepared from the leaves, bulbs and roots, and the development of suitable tissue culture protocols for the bulk propagation of the species under study. Common underlying symptoms in the majority of ailments treated with traditional remedies prepared from Eucomis species are pain and inflammation. Prostaglandins are the primary mediators of the body's response to pain and inflammation, and are formed from essential fatty acids found in cell membranes. This reaction is catalysed by cyclooxygenase, a membrane-associated enzyme occurring in two isoforms, COX-1 and COX-2. Non-steroidal anti-inflammatory drugs (NSAIDs) act by inhibiting the activity of COX. The use of commercially available COX-1 inhibitors is associated with side-effects, including gastric and renal damage. Selective COX-2 inhibitors do not have these undesired effects, and are thus potentially very valuable to the pharmaceutical industry. The relative inhibitory effects of different extracts of Eucomis species on the activities of purified cyclooxygenase enzyme preparations (COX-1 in sheep seminal vesicles, COX-2 in sheep placenta) were assessed. The COX-1 assay was used to screen extracts from 10 species of Eucomis and one hybrid species at a concentration of 250 μg mℓ ¯¹ in the assay. High levels of anti-inflammatory activity were exhibited by the ethanolic extracts prepared from the dried leaves, bulbs and roots. Aqueous extracts (screened at 500 μgmℓ ¯¹) showed much lower levels of activity. In general, the highest levels of anti-inflammatory activity were observed for the ethanol bulb and root extracts. Comparison of the activity of the bulb extracts from bulbs harvested in summer and winter revealed very little difference in COX-1 inhibitory activity. Eucomis extracts were separated using thin layer chromatography. The plates were developed in a solvent system of benzene : 1,4-dioxan : acetic acid, 90:25:4 and stained with anisaldehyde-sulphuric acid. The TLC fingerprints prepared from these extracts showed different chemical profiles for the leaf, bulb and root extracts, but many similarities between the different species. The position of the active R[f] fractions was determined and correlated with the TLC-fingerprints. The most widely utilized species medicinally, E. autumnalis subspecies autumnalis, was chosen for further investigation. The fluctuation of anti-inflammatory activity with season and physiological age was determined. Young plants were found to have high levels of COX-1 inhibitory activity, particularly in the leaves. As the plant matured, higher levels of activity were associated with the bulb and root extracts. The antiinflammatory activity of the leaf, bulb and root extracts varied slightly throughout the year, with the highest levels detected towards the end of the growing season, shortly before the onset of dormancy. This study of E. autumnalis autumnalis was extended to investigate the effects of environmental conditions on the levels of COX-1 inhibitory activity. The extent to which high temperature and light intensity, fertilization of the plants in summer with Kelpak preparations, and cold storage of the dry bulbs during winter, affected the levels of active compounds accumulated, was determined. Kelpak application decreased the anti-inflammatory activity of the leaf, bulb and root extracts, while high temperature / high light intensity had no significant effect on the COX-1 inhibitory activity of the leaf or bulb extracts. The root extract did show a significant increase in anti-inflammatory activity. Bulbs that were removed from the soil and stored at 10°C exhibited significantly higher COX-1 inhibitory activity than the control bulbs maintained in the soil. Higher COX-1 inhibition was observed in the leaf extracts from these plants when harvested half-way through the growing season. No significant difference was observed at this stage between the bulb and root extracts from the different treatments. Bioassay-guided fractionation (using the COX-1 assay) was used to isolate the active principle(s) in the bulb extract. The bulb material was subjected to serial extraction using a Soxhlet apparatus. The ethyl acetate fraction showed the highest levels of COX-1 inhibition, and this was further fractionated using a Sephadex LH-20 column and a solvent system of cyclohexane : dichloromethane : methanol (7:4:1). The most active fraction from this separation was then purified using semi-preparative TLC and HPLC. The primary compound eluting in this fraction had an IC₅₀ value of 14.4 μgmℓ ¯¹ in the COX-1 assay, and 30.5 μgmℓ ¯¹ in the COX-2 assay. This compound was tentatively characterized as a phenol ring attached to a conjugated hydrocarbon chain (with a molecular weight of 390), and was a potent COX-1 inhibitor. The COX-2 / COX-1 inhibitory ratio was calculated to be 2.1. A second, highly active compound, with IC₅₀ values of 25.7 μgmℓ ¯¹ and 21.8 μgmℓ ¯¹ in the COX-1 and COX-2 assays respectively, crystalized from one of the Sephadex LH-20 column fractions. This compound was identified as a spirostane-type triterpenoid, eucosterol, previously isolated from Eucomis species but not specifically linked to the pharmacological activity of the extracts. This compound showed COX-2 / COX-1 inhibitory ratio of 0.8, indicating that it was a selective COX-2 inhibitor. Two further compounds were identified from this extract, after crystallization from different fractions obtained from Sephadex LH-20 chromatography. These were both homoisoflavanones, 5,7-dihydroxy-6-methoxy-3-(4-methoxy benzyl)-chroman-4-one, and 5,7-dihydroxy-3-(4-methoxy benzyl)-chroman-4-one [eucomin], the latter having been isolated previously. The first compound exhibited very low levels of both COX-1 and COX-2 inhibition, and the second compound (eucomin) exhibited high COX-1, but low COX-2 inhibitory activity. The in vitro propagation of the genus Eucomis was undertaken primarily to provide a source of material for experimentation, and also to optimize this technique for the bulk production of plants for commercial and conservation purposes. Multiple shoot production was initiated from leaf explants, in all species studied. A Murashige and Skoog (MS) medium, supplemented with 100 mg ℓ ¯¹ myo-inositol, 20 g ℓ ¯¹ sucrose, and solidified with 2 g ℓ ¯¹ Gelrite® was used. The optimal hormone combination for shoot initiation in the majority of species was determined to be 1 mg ℓ ¯¹ NAA and 1 mg ℓ ¯¹ BA. Optimal root initiation was demonstrated on media supplemented with 1 mg ℓ ¯¹ IAA, IBA or NAA, depending on species. A continuous culture system using this protocol produced 25-30 plantlets per culture bottle, with 10-25 specimens per bottle available for acclimatization. To maximize plantlet survival, different support media used during the acclimatization process were necessary. Certain species responded best on a vermiculite medium, while perlite (which holds less water) was necessary for the optimal survival rate of other species. Acclimatized plantlets were repotted in a sand : soil mix (1:1). Further experimental work aimed to determine the factors affecting the accumulation of anti-inflammatory compounds in in vitro plantlets. Extracts prepared from in vitro plantlets showed high levels of COX-1 and COX-2 inhibitory activity, with a C0X-2/C0X-1 ratio of 1.1. High levels of sucrose (40 g ℓ ¯¹) significantly increased the number of shoots initiated, but had no effect on the anti-inflammatory activity. Low levels of sucrose (10 g ℓ ¯¹) led to a significant decrease in COX-1 inhibition. Changing the levels of nitrogen in the medium (but not the ratio of nitrate to ammonium ions) had no significant effect on the COX-1 inhibitory activity of the extracts. Callus was initiated from leaf explants and experiments were conducted to maximize callus proliferation. Optimal callus growth occurred on an MS medium supplemented with 100 mg ℓ ¯¹ myo-inositol, 30 g ℓ ¯¹ sucrose, 2 g ℓ ¯¹ Gelrite® , and a hormone combination of 10 mg ℓ ¯¹ 2,4-D and 2 mg ℓ ¯¹ kinetin. Callus cultures maintained in the dark grew best. Callus extracts tested in the COX assays (250 μgmℓ ¯¹) showed a higher level of COX-2 inhibition (69%) than COX-1 inhibition (46%). Lastly, the conclusive identification of the species under study was attempted, using DNA fingerprinting. Protocols were developed for the extraction of DNA from the leaves of Eucomis plants, and the optimization of the AP-PCR technique. Random sequence (10-base) oligonucleotide primers were screened, each primer used singly. Primers were selected on the basis that more than five distinct bands were detected. Differences were detected in the amplification products visualized using nondenaturing agarose gel electrophoresis stained with ethidium bromide. This work provides the basis for further studies into the phylogenetic relationships between the various species (and hybrids) of Eucomis. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1999.
270

Genetic variation of brown rot blossom blight pathogens and their hosts sweet and sour cherry / Kaulavaisinių moniliozės sukėlėjų ir trešnės bei paprastosios vyšnios genetinė variacija

Frercks, Birutė 08 October 2014 (has links)
The aim of the research. To evaluate the genetic diversity in sweet and sour cher-ry populations, to characterize the injuries to blossoms and fruits caused by blossom blight brown rot, to identify the species composition of Monilinia patho-gens and to analyse the DNA polymorphism within and among pathogens popula-tions. Main tasks: 1. To analyse the genetic diversity of sweet and sour cherry cultivars and wild cherry population, growing in west Lithuania, using molecular marker methods (AFLP and SSR). 2. To determine factors affecting injuries caused by blossom blight. 3. To investigate characteristics of brown rot agent M. fructigena development in sweet and sour cherry cultivars differing in resistance to brown rot. 4. To identify species composition of Monilinia spp. in IH LRCAF stone fruit collection based on PCR methood and to evaluate inter- and intraspecific DNA polymorphism of Monilinia spp. based on AFLP method. / Tyrimų tikslas. Įvertinti trešnės ir paprastosios vyšnios populiacijų ge-netinę įvairovę, ištirti trešnės ir paprastosios vyšnios žiedų bei vaisių užsikrėtimo kaulavaisinių monilioze mechanizmus, nustatyti šios ligos sukėlėjų Monilinia rūšinę sudėtį bei išanalizuoti jų tarprūšinį ir vidurūšinį DNR polimorfizmą. Tyrimų uždaviniai: 1. Išanalizuoti skirtingų pagal atsparumą moniliozinei degligei LAMMC SDI kaulavaisinių kolekcijoje augančių trešnės ir vyšnios veislių ir Vakarų Lietuvo-je augančios laukinės trešnės populiacijos genetinę įvairovę, naudojant molekuli-nius metodus (SSR ir PFIP) bei palyginti PFIP pradmenų kombinacijų informaty-vumo rodiklius. 2. Nustatyti žiedų pažeidimo moniliozine deglige (M. laxa) veiksnius: ištirti žiedo da¬lių atsparumą moniliozinei degligei, nustatyti kuriame žiedo raidos tarpsnyje jie yra jautriausi, įvertinti, ar kuokelių mechaninis pašalinimas (kastravimas) turi įtakos užsikrėtimui moniliozine deglige ir nustatyti ar žiedų ap-dulkinimas gali aktyvuoti augalo imunines reakci¬jas ir užkirsti kelią patogenui patekti į žiedo vidų. 3. Ištirti rudojo puvinio sukėlėjo M. fructigena vystymosi ypatumus kontrastinėse pa¬gal atsparumą rudajam puviniui trešnės ir vyšnios veislėse. Nusta-tyti, ar vaisiai jautresni patogenui yra nokimo pradžioje ar techninės brandos (skynimo) metu, įvertinti vaisių mechani¬nio pažeidimo poveikį užsikrėtimui ruduo-ju puviniu. 4. Identifikuoti Monilinia spp. LAMMC SDI kaulavaisinių kolekcijos augyne rūšinę sudėtį PGR... [toliau žr. visą tekstą]

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