122 research outputs found

    Estimating genetic diversity of onion germplasm via morphological, agronomic, and biochemical descriptors

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    A divergência genética de 64 acessos de cebola (Allium cepa L.) tropicais e subtropicais do banco de germoplasma da Embrapa Hortaliças foi avaliada utilizando 23 descritores morfológicos, bioquímicos e agronômicos. A distância generalizada de Mahalanobis (D²) foi usada como medida de dissimilaridade e os métodos de otimização de Tocher e hierárquico do Vizinho mais Próximo foram empregados para o agrupamento dos acessos. O germoplasma de cebola avaliado apresentou base genética relativamente ampla. As cultivares EX 3000 e Régia foram os acessos geneticamente mais similares. A maior distância genética estimada foi entre os acessos VAL 14 e Beta Cristal. O método de otimização de Tocher proporcionou a formação de treze grupos, enquanto o procedimento hierárquico do vizinho mais próximo possibilitou a formação de doze grupos (corte com 43% de dissimilaridade) A maioria dos acessos dos tipos Grano e Granex, agronomicamente considerados de dias curtos e com ciclo de maturação precoce, se concentraram em mesmo grupo de similaridade genética. À exceção do acesso Tampico White, os demais acessos de bulbos brancos do tipo indústria (Beta Cristal; Dehydrator # 8; Dehydrator # 6; Primero e White Creole) exibiram estreito relacionamento. Os acessos TX 24, Baia Periforme Super Precoce, EX 3001, Excel, Red Creole, H 688, Franciscana IPA 10 e Roxa IPA 3 exibiram alta dissimilaridade genética. Os caracteres teor de açúcares totais, comprimento de bulbo, número de dias para a colheita, porcentagem de bulbos com diâmetro entre 70 e 90 mm e massa média de bulbos foram responsáveis por 58% de toda a variabilidade genética observada entre os acessos. O estudo da divergência entre acessos é importante subsídio na escolha de parentais divergentes e complementares a fim de desenvolver populações segregantes com ampla base genética em programas de melhoramento genético de cebolas tropicais.The genetic diversity of 64 tropical and subtropical onion accessions (Allium cepa L.) belonging to the Embrapa Hortaliças collection was estimated using 23 morphological, agronomic, and biochemical descriptors. Methods of multivariate statistical analysis (Mahalanobis' D² distances, Tocher's cluster analysis and nearest-neighbor method) were employed in order to obtain the average genetic distances among accessions and to perform the clustering. The onion germplasm displayed a relatively large genetic base. Cultivars EX 3000 and Régia were the two most similar accessions. The highest mean genetic distance was observed between cultivars VAL 14 and Beta Cristal. The Tocher's optimization method revealed the formation of 13 groups, whereas the nearest-neighbor method revealed the formation of 12 groups (cutting point of 43% of dissimilarity. The majority of the accessions belonging to Grano and Granex cultivars (agronomically classified as short-day and early-maturing types) clustered together in the same group. The white bulb accessions for processing (Beta Cristal; Dehydrator # 8; Dehydrator # 6; Primero and White Creole), with the exception of Tampico White, displayed a small genetic divergence. The accessions TX 24, Baia Periforme Super Precoce, EX 3001, Excel, Red Creole, H 688, Franciscana IPA 10 and Roxa IPA 3 displayed a large genetic divergence. The descriptors total sugar content, bulb length, number of days from planting to harvesting (i.e. plant cycle), percentage of bulbs with transversal diameter between 70 and 90 mm, and average bulb weight were responsible for 58% of the genetic variability present among accessions. Studies of divergence among accessions are important to choose divergent parentals but complementary genetic materials would allow the development of useful segregating populations with wide genetic basis for tropical onion breeding programs

    A PRODUÇÃO SOBRE O PROFESSOR NO CENTRO-OESTE – um estudo interinstitucional

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    O presente trabalho resulta da pesquisa ”A produção acadêmica sobre o professor: estudo interinstitucional da Região Centro-Oeste”. Essa investigação envolve os Programas de Pós-Graduação em Educação da Região Centro- Oeste: Universidade de Brasília (UNB), Universidade Federal de Goiás (UFG), Universidade Federal de Mato Grosso (UFMT), Universidade Federal de Mato Grosso do Sul (UFMS), Universidade Federal de Uberlândia (UFU) e Universidadede Uberaba (UNIUBE). – Grupo PACOP (Produção Acadêmica do Centro-Oeste sobre Professores). Tomamos como objeto de estudo as dissertações e teses defendidas nos referidos programas no período de 1999-2005, que trabalham o tema professores(as). Destacamos o caráter cooperativo da investigação, ele tem permitido agregar pesquisadores de várias disciplinas e de vários contextos da Região Centro-Oeste, num esforço de superar a fragmentação da produção acadêmica e pensar a questão professores(as) de maneira que articule as realidades regional, nacional e internacional. As atividades já realizadas abrangem levantamento da produção, leitura integral dos trabalhos, fichamento e análise das dissertações sob os seguintes aspectos: tema; referencial teórico, metodologia, concepções de educação e de professor. Os resultados, sabidamente iniciais, coincidem em vários aspectos com os das pesquisas existentes, contudo, apontam para características bem próprias dessa produção regional

    Identification of sources of seedling resistance to Phytophthora capsici in Cucumis melo

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    The employment of genetic resistance to minimize yield losses induced by Phytophthora capsici remains unexplored in melon (Cucumis melo). A diverse collection of melon accessions was evaluated against P. capsici isolates at the seedling stage. In the frst screening assay, 105 accessions were evaluated using isolate PCpe-04 obtained from cucumber (Cucumis sativus). In a second assay, 31 accessions displaying high levels of resistance in the frst assay were challenged with a distinct isolate (PCpe-09 also from cucumber). In a third assay, a subset of 14 selected accessions was re-evaluated using isolates PCpe-09 and PCmo-07 (from strawberry). In the last screening, seven accessions with high levels of resistance across all assays were challenged with fve isolates from representative host species [PC-Vagem (snap bean), PCp-129 (Capsicum chinense), PCp-155 (C. annuum), PCpe-09 and PCmo-07] to assess their reaction against a varied sample of P. capsici isolates. For two accessions (CNPH-093 and L040), all plants remained free of symptoms after inoculation with all fve isolates. Accessions WMR-29, CNPH 084, CNPH 088 and CNPH 092 were also free of symptoms to all isolates, except PCmo-07. These large-spectrum resistance sources might be useful for breeding programs aiming to incorporate resistance against P. capsici in elite melon lines

    Synthesis of 7-Chloroquinoline Derivatives Using Mixed Lithium-Magnesium Reagents

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    We have prepared a library of functionalized quinolines through the magnesiation of 7-chloroquinolines under mild conditions, employing both batch and continuous flow conditions. The preparation involved the generation of mixed lithium-magnesium intermediates, which were reacted with different electrophiles. Mixed lithium-zinc reagents allowed the synthesis of halogenated and arylated derivatives. Some of the synthesized 4-carbinol quinolines have shown interesting antiproliferative properties, their hydroxyl group being a suitable amino group bioisostere. We also report a two-step approach for optically active derivatives

    Genotyping of polymorphisms associated with male-sterility systems in onion accessions adapted for cultivation in Brazil

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    A produção em escala comercial de sementes híbridas de cebola (Allium cepa) tem sido conduzida com o emprego de dois sistemas de macho-esterilidade do tipo genética-citoplasmática (CMS-S e CMS-T) em associação ao citoplasma normal (macho-fértil). No entanto, a análise molecular desses diferentes tipos citoplasmáticos ainda não está disponível para um grande número de acessos de cebola adaptados para cultivo em regiões tropicais. Além de adaptação às condições edafoclimáticas do Brasil, muitos desses acessos apresentam tolerância a doenças, sendo de potencial valor como genitores de híbridos. O presente trabalho visou identificar os tipos citoplasmáticos de acessos de cebola de diferentes grupos morfoagronômicos de interesse para o melhoramento genético no Brasil, usando a reação da polimerase em cadeia (PCR) com 'primers' específicos para regiões polimórficas do genoma mitocondrial de cebola. Foi observada, nos 66 acessos amostrados, a presença dos três principais tipos de citoplasma descritos para cebola (S, N e T). Foi constatada maior frequência do citoplasma S (56%) seguido do citoplasma T (25,8%). Em 18,2% das amostras, foi encontrado exclusivamente o citoplasma N. Essa caracterização pode ser útil para guiar a escolha de materiais genéticos dentro dos programas de melhoramento com objetivo de desenvolver cultivares híbridas adaptadas às condições tropicais

    The Brazilian Developments on the Regional Atmospheric Modeling System (BRAMS 5.2): An Integrated Environmental Model Tuned for Tropical Areas

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    We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System where different previous versions for weather, chemistry and carbon cycle were unified in a single integrated software system. The new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. Together with the description of the main features are examples of the quality of the transport scheme for scalars, radiative fluxes on surface and model simulation of rainfall systems over South America in different spatial resolutions using a scale-aware convective parameterization. Besides, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America are shown. Atmospheric chemistry examples present model performance in simulating near-surface carbon monoxide and ozone in Amazon Basin and Rio de Janeiro megacity. For tracer transport and dispersion, it is demonstrated the model capabilities to simulate the volcanic ash 3-d redistribution associated with the eruption of a Chilean volcano. Then, the gain of computational efficiency is described with some details. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5 km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding on its functionalities and skills are discussed. At last, we highlight the relevant contribution of this work on the building up of a South American community of model developers

    The Brazilian developments on the Regional Atmospheric Modeling System (BRAMS 5.2): an integrated environmental model tuned for tropical areas

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    We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS), in which different previous versions for weather, chemistry, and carbon cycle were unified in a single integrated modeling system software. This new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. The description of the main model features includes several examples illustrating the quality of the transport scheme for scalars, radiative fluxes on surface, and model simulation of rainfall systems over South America at different spatial resolutions using a scale aware convective parameterization. Additionally, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America, are shown. Atmospheric chemistry examples show the model performance in simulating near-surface carbon monoxide and ozone in the Amazon Basin and the megacity of Rio de Janeiro. For tracer transport and dispersion, the model capabilities to simulate the volcanic ash 3-D redistribution associated with the eruption of a Chilean volcano are demonstrated. The gain of computational efficiency is described in some detail. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5 km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near-surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding both its functionalities and skills are discussed. Finally, we highlight the relevant contribution of this work to building a South American community of model developers.CNPqFAPESPEarth System Research Laboratory at the National Oceanic and Atmospheric Administration (ESRL/NOAA), Boulder, USAInst Nacl Pesquisas Espaciais, Ctr Previsao Tempo & Estudos Climat, Cachoeira Paulista, SP, BrazilDiv Ciência da Computação, Instituto Tecnológico de Aeronáutica, São José dos Campos, SP, BrazilUniv Estadual Paulista Unesp, Fac Ciencias, Bauru, SP, BrazilCtr Meteorol Bauru IPMet, Bauru, SP, BrazilUniv Fed Sao Paulo, Dept Ciencias Ambientais, Diadema, SP, BrazilUniv Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Sao Paulo, SP, BrazilUniv Fed Campina Grande, Dept Ciencias Atmosfer, Campina Grande, PB, BrazilEmbrapa Informat Agr, Campinas, SP, BrazilUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos, SP, BrazilUniv Fed Rio Grande do Norte, Dept Ciencias Atmosfer & Climat, Programa Pos Grad Ciencias Climat, Natal, RN, BrazilInst Nacl Pesquisas Espaciais, Ctr Ciencias Sistema, Sao Jose Dos Campos, SP, BrazilUniv Fed Sao Joao Del Rei, Dept Geociencias, Sao Joao Del Rei, MG, BrazilInst Nacl Pesquisas Espaciais, Lab Associado Computacao & Matemat Aplica, Sao Jose Dos Campos, BrazilUniv Evora, Inst Ciencias Agr & Ambientais Mediterr, Evora, PortugalUniv Lusofona Humanidades & Tecnol, Ctr Interdisciplinar Desenvolvimento Ambient Gest, Lisbon, PortugalUniv Fed Pelotas, Fac Meteorol, Pelotas, RS, BrazilUnive Tecnol Fed Parana, Londrina, PR, BrazilNASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Goddard Earth Sci Technol & Res Global Modeling &, Greenbelt, MD USAUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos, SP, BrazilUniv Fed Sao Paulo, Inst Ciencia & Tecnol, Sao Jose Dos Campos, SP, BrazilCNPq: 306340/2011-9FAPESP: 2014/01563-1FAPESP: 2015/10206-0FAPESP: 2014/01564-8Web of Scienc
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