1,430 research outputs found

    Glyphosate translocation in herbicide tolerant plants

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    The objective of this study was to evaluate glyphosate translocation in glyphosate-tolerant weed species (I. nil, T. procumbens and S. latifolia) compared to glyphosate-susceptible species (B. pilosa). The evaluations of 14C-glyphosate absorption and translocation were performed at 6, 12, 36 and 72 hours after treatment (HAT) in I. nil and B. pilosa, and only at 72 HAT in the species T. procumbens and S. latifolia. The plants were collected and fractionated into application leaf, other leaves, stems, and roots. In S. latifolia, approximately 88% of the glyphosate remained in the application leaf and a small amount was translocated to roots at 72 HAT. However, 75% of the herbicide applied on T. procumbens remained in the leaf that had received the treatment, with greater glyphosate translocation to the floral bud. It was concluded that the smaller amount of glyphosate observed in S. latifolia and T. procumbens may partly account for their higher tolerance to glyphosate. However, I. nil tolerance to glyphosate may be associated with other factors such as metabolization, root exudation or compartmentalization, because a large amount of the herbicide reached the roots of this species.Objetivou-se neste estudo avaliar a translocação de glyphosate em plantas tolerantes (Ipomoea nil, Tridax procumbens e Spermacoce latifolia) e suscetível (Bidens pilosa) a esse herbicida. As avaliações de absorção e translocação do 14C-glyphosate em I. nil e B. pilosa foram efetuadas às 6, 12, 36 e 72 horas após a aplicação do herbicida (HAT), e em T. procumbens e S. latifolia, às 72 HAT. As plantas foram coletadas e fracionadas em: folha de aplicação, demais folhas, caules e raízes; em T. procumbens e S. latifolia, avaliou-se a presença do produto na inflorescência da planta. Em S. latifolia, aproximadamente 88% do glyphosate permaneceu na folha de aplicação, e pequena quantidade translocou para as raízes. Todavia, em T. procumbens, 75% do herbicida permaneceu na folha que recebeu a aplicação, observando-se maior translocação na inflorescência em relação às raízes. Conclui-se que a menor translocação do glyphosate observada em S. latifolia e T. procumbens pode ser um dos fatores responsáveis pela maior tolerância dessas espécies ao herbicida, ao passo que em I. nil a metabolização, a exsudação radicular ou a compartimentalização podem favorecer a tolerância, já que grande quantidade do produto atingiu as raízes da espécie

    Green manure legumes affect seasonal soil and leaf CO2 exchange rates in an olive rainfed orchard

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    Management methods that decrease requirement for agricultural chemicals are needed to reduce adverse environmental impacts. Moreover, they can play an important role in atmospheric C02 emission and fixation. We propose green manure legumes to reduce erosion, soil compaction and nitrate pollution, to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the nutritional value of food products. The research was carried out near Mirandela, Northeast Portugal, on a 15- year commercial olive orchard (Olea europaea L. cv. Cobrançosa), grown under rainfed conditions

    Sustainable management of olive rainfed orchards by the introduction of leguminous cover crops

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    The olive sector has a crucial economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application are still generalized practices. However, these practices oppose the recommendations of UE Common Agricultural Policy and thus, management methods that decrease requirement for agricultural chemicals are needed to reduce adverse environmental impacts. Moreover, they can play an important role in atmospheric C01 emission and fixation. We propose green manure legumes to reduce erosion, soil compaction and nih·ate pollution, to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the safety and nutritional value of food products. The 3-yearfield study carried out in Northeast Portugal revealed that self-reseeding annual legumes is a promising strategy since increase the summer soil water content, the vegetative growth and the physiological tree pe1jormance, that was reflected in a 38% higher cumulative yield then tillage techniques.PTDC-AGR-AAM/098326/200

    Layered double hydroxide based active corrosion protective sealing of plasma electrolytic oxidation/sol-gel composite coating on AA2024

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    This work reports a novel approach for growing layered double hydroxide (LDH) films on any plasma electrolytic oxidation (PEO) coated AA2024 independently of the nature of the PEO coating. The specific PEO coating chosen to carry out this work is considered to be not suitable for direct LDH growth because of phase composition and morphological features. In this paper, we describe a new methodology that consists of covering the PEO coating with a thin layer of aluminum oxide based xerogel as the source of aluminate ions for subsequent in-situ LDH growth. X-ray diffraction (XRD) and scanning electron microscope (SEM) images showed a successful formation of LDHs on the surface. An improvement in terms of active corrosion protection was also demonstrated by electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET).publishe

    Leguminous cover crops improve the profitability and the sustainability of rainfed olive (Olea europaea L.) orchards: from soil biology to physiology of yield determination

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    The olive sector has a crucial economic, social, cultural and ecological relevance in the Mediterranean region, where tillage and herbicides application still are generalized practices. However, these techniques oppose to the recommendations of UE policy. Thus, other methods are needed to reduce adverse environmental impacts and to improve biodiversity, soil carbon sink and fertility, to save fossil fuels and to increase yield and the safety and nutritional value of food products. Meanwhile, since Mediterranean basin is particularly vulnerable to climate change, including lower precipitation in summer, olive tree will experiment some hard changes, mainly under rainfed conditions. Therefore, we propose an adequate management of cover crops to shift tillage and herbicides, in order to minimize runoff and evaporation water losses, conserve soil moisture storage and promote the infiltration of water in soil. The experiment was carried out during 4 years on a commercial orchard (cv. Cobrançosa) in Northeast Portugal. The treatments laid out were: (1) ordinary tillage techniques (OT) used by local growers (two tillage trips per year); (2) cover crop with self-reseeding annual legume species (AL); (3) natural vegetation fertilized (NVF) with 60 kg N hm2 (as in OT); (4) natural vegetation (NV) left unfertilized. The results revealed that AL treatment is the best option, reaching 37, 53 and 95% higher cumulative yield than NVF, OT and NV, respectively, in a closely association with greater physiological performance during the summer, mainly evidenced by lower oxidative damage and by favourable changes in water status and net photosynthetic rate, due to lower stomatal and mesophyll limitations. Moreover, the AL covered soil presented considerable microbial diversity and enzymatic activities, which may contribute to promote and conserve soil quality and health, as well the stability of ecosystems. Thus, leguminous cover crops improve the profitability and the sustainability of rainfed olive orchards.info:eu-repo/semantics/publishedVersio

    Sequestro de carbono no olival: mito ou realidade?

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    O homem, através de diversas atividades econom1cas, tem contribuído para o aumento da concentração de dióxido de carbono (C02) na atmosfera. A queima de combustíveis fósseis, o fabrico de cimento a partir de carbonatos e a desflorestação com expansão da área agrícola são as principais atividades humanas associadas à emissão de C02 para a atmosfera . O C02 é um gás com efeito de estufa, capaz de reter radiação térmica, contribuindo para o aquecimento global. Para mitiga r o aquecimento global têm vindo a ser promovidos mecanismos que retirem carbono (C) da atmosfera e o fixem em formas inertes nos ecossistemas terrestres. O sequestro de carbono ocorre principalmente através da fotossíntese em que organismos fotossintéticos como as plantas fixam carbono e libertam oxigénio para a atmosfera. A vegetação terrestre e os solos podem, assim, constituir-se como importantes reservatórios de carbono e contrariar a tendência de aumento da concentração de C02 na atmosfera. Atendendo a que os apoios comunitários na nova PAC serão sobretudo concedidos em função dos serviços ecossistémicos que os diferentes setores prestarem à sociedade e que o sequestro de carbono é um dos principais serviços ecossistémicos que a agricultura pode prestar, apresenta-se uma estimativa do carbono que um olival tradicional de sequeiro (árvores mais solo) pode fixar nos primeiros 10 anos de vida a seguir à instalação. Foi tido em conta a quantidade de folhas, raminhos, casca e lenho de cada um dos diversos componentes da árvore, a percentagem de matéria orgânica e o teor de carbono na matéria orgânica de cada um daqueles componentes. No solo, foi tido em conta o potencial de acumulação de carbono no solo estimado a partir de uma situação inicial de solo mobilizado passando para uma situação em que se permite o desenvolvimento de vegetação herbácea no coberto. Assim, uma árvore bem desenvolvida com 10 anos de idade representa uma quantidade de carbono de 9, 71 kg árvore·1 [75% na parte aérea (medida) e 25% na parte radicular (estimada)], o que representa 2,0 t C _ha·1 • No solo, se durante 10 anos forem implementadas medidas que promovam o acréscimo em 1% no teor de matéria orgânica do solo (profundidade 0-20 cm) relativamente à massa total do solo, serão fixadas 14 t C ha-1

    Comparing N recovery from legumes grown as green manures in olive orchards

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    Green manuring is probably the only option for extending on a great scale the acreage of organic fanning in the perennial crops of the Mediterranean basin such as olive groves. Olive growers, in general, do not have animals so the availability of organic manures is not sufficient to maintain soil fertility. In addition, the organic composts approved for organic farming on the market have high prices and are sometimes speculative, in relation to their fertiliser value (Rodrigues et al., 2006). In NE Portugal there is a long tradition in the cultivation of white lupin (Lupinus a/bus) as a means of improving soil fertility. However, little is known about the dry matter yield and N fixation potential of lupin in these agrosystems, and also of the transfer of fixed N to the trees. In this work the results of dry matter yield and N recovery by lupin, vetch (Vicia villosa) and a mixture of self-reseeding annual legumes are presented. The trial also included plots of oats (Avena saliva) and natural vegetation

    Efeito de formulações na absorção e translocação do glyphosate em soja transgênica

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    Este trabalho teve como objetivo avaliar a absorção e translocação de glyphosate em diferentes formulações por plantas de soja (variedade CD 219RR). Para isso, aplicou-se o 14C-glyphosate misturado à calda em três formulações comerciais (Roundup Ready® e R. Transorb®, ambas contendo o sal de isopropilamina, e Zapp Qi®, formulado à base do sal potássico), quando as plantas apresentavam o segundo trifólio completamente expandido. Transcorridas 4, 16, 40 e 64 horas após a aplicação, as plantas foram coletadas e fracionadas, separando-se a folha de aplicação (trifólio), a parte aérea, as raízes e os nódulos radiculares. O 14C-glyphosate não-absorvido foi recuperado e contado por meio da lavagem da folha (metanol 80%). Entre as formulações foi observada variação na penetração e na translocação do 14C-glyphosate para as diferentes partes avaliadas. Todavia, em todas as formulações a maior absorção se deu nos intervalos posteriores a 16 horas da aplicação. Em relação ao total de herbicida encontrado nas plantas de soja, maior percentual na parte aérea foi observado quando se aplicou o Zapp Qi® (sal potássico) e, nas raízes, o R. Transorb® (sal de isopropilamina). Detectou-se a presença de 14C glyphosate nos nódulos radiculares das plantas em todos os tratamentos, sendo o maior percentual observado quando se utilizou R. Transorb®, 40 horas após a aplicação (0,13% do total medido ou 0,4% considerando somente o total presente na planta). Os resultados reforçam a hipótese de que o glyphosate pode prejudicar a simbiose entre rizóbio e soja, uma vez que o microssimbionte também apresenta em seu metabolismo a EPSPS, sensível a esse herbicida.This study was carried out to evaluate the absorption and translocation of glyphosate formulations in genetically modified (GM) soybean by applying 14C-glyphosate mixed to three glyphosate formulations (Roundup Ready® and R. Transorb® - both with isopropylamine salt, and Zapp Qi®, formulated from potassic salt ), using a precision micro syringe. Plant samples were collected after herbicide application (4, 16, 40 and 64 hours) and then divided into leaf (trifolium), aerial part, roots and root nodes for radiation reading. 14C-glyphosate that was not absorbed was recovered and counted by washing the leaf with methanol. Penetration and translocation of 14C-glyphosate to the different parts evaluated was found to vary. However, the highest absorption was verified at intervals after 16 hours of application. The highest herbicide percentage in the aerial part of the soybean plants was found when Zapp (potassic salt) was applied on the aerial part and when isopropylamin salt was applied on the roots; 14C-glyphosate was found in the plant root nodules in all treatments, with the highest percentage being observed with R. Transorb®, 40 hours after application (0.13% of the total measured or 0.4%, considering only the plant total). Results highlight the hypothesis that glyphosate could harm symbiosis between rhizobium and soybean, since the former also shows in its metabolism EPSPS, which is susceptible to this herbicide

    Cercosporin production by Cercospora coffeicola isolates: spectrophotometry and HPLC quantification and image analysis

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    Cercosporin has excellent properties of photosensitization that have been widely used in organophotocatalyst and photodynamic therapy as well as an antimicrobial agent. Therefore, there is a need to quantify it accurately with accessible methods. A comparative analysis of cercosporin quantification obtained by spectrophotometry (SPEC) and high-performance liquid chromatography (HPLC) was performed for nineteen Cercospora coffeicola isolates from different coffee-producing municipalities in Brazil. Image analysis of cercosporin crystals was performed in isolates with either high or low production of the toxin. Our results show that SPEC and HPLC are equally valid for the cercosporin evaluation of C. coffeicola cultures grown in vitro. The isolates with high cercosporin production had a higher crystal number and size when compared to the one with low cercosporin productioninfo:eu-repo/semantics/publishedVersio

    Multigene germline testing usefulness instead of BRCA1/2 single screening in triple negative breast cancer cases

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    Producción CientíficaTriple negative breast cancer is considered as the worst aggressive subtype with poor prognosis. Recent studies suggest a hereditary component is involve in TNBC development, especially in young patients. However, genetic spectrum remains unclear. Our purpose was to evaluate the usefulness of multigene panel testing in triple negative patients respect overall breast cancer cases as well as contributing to elucidate which genes are most implicated in TNBC development with respect to the remaining breast cancer subtypes. A breast cancer patients sample comprised of 100 triple negative breast cancer patients and 100 other breast cancer subtypes patients were analyzed by Next-Generation Sequencing using an On-Demand panel which included 35 predisposition cancer genes associated with inherited cancer susceptibility. Triple negative breast cancer patients obtained a higher percentage of germline variant carriers. ATM, PALB2, BRIP1 and TP53 were the most non-BRCA mutated genes. Moreover, triple negative breast cancer patients without family history related which proved to be carriers were diagnosed at significant earlier age. As conclusion, our study reinforces the usefulness of multigene panel testing in breast cancer cases but specifically in those with triple negative subtype regardless family history.Junta de Castilla y León. Dirección Regional de Salud de Castilla y León (GRS/2180/A/2020 y GRS/2351/A/2021
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