475 resultados para Euterpe oleracea


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Nectria brassicae Ellis & Sacc. in Sacc.

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Th. 1. Klio, Euterpe, Thalia, Melpomene -- Th. 2. Terpsichore, Erato, Polymnia, Urania, Kalliope.

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Latin translation at foot of page.

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Optical tweezers are widely used for the manipulation of cells and their internal structures. However, the degree of manipulation possible is limited by poor control over the orientation of the trapped cells. We show that it is possible to controllably align or rotate disc-shaped cells-chloroplasts of Spinacia oleracea-in a plane-polarized Gaussian beam trap, using optical torques resulting predominantly from circular polarization induced in the transmitted beam by the non-spherical shape of the cells.

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Evidence indicates that cruciferous vegetables are protective against a range of cancers with glucosinolates and their breakdown products considered the biologically active constituents. To date, epidemiological studies have not investigated the intakes of these constituents due to a lack of food composition databases. The aim of the present study was to develop a database for the glucosinolate content of cruciferous vegetables that can be used to quantify dietary exposure for use in epidemiological studies of diet-disease relationships. Published food composition data sources for the glucosinolate content of cruciferous vegetables were identified and assessed for data quality using established criteria. Adequate data for the total glucosinolate content were available from eighteen published studies providing 140 estimates for forty-two items. The highest glucosinolate values were for cress (389 mg/100 g) while the lowest values were for Pe-tsai chinese cabbage (20 mg/100 g). There is considerable variation in the values reported for the same vegetable by different studies, with a median difference between the minimum and maximum values of 5.8-fold. Limited analysis of cooked cruciferous vegetables has been conducted; however, the available data show that average losses during cooking are approximately 36 %. This is the first attempt to collate the available literature on the glucosinolate content of cruciferous vegetables. These data will allow quantification of intakes of the glucosinolates, which can be used in epidemiological studies to investigate the role of cruciferous vegetables in cancer aetiology and prevention.

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Maternal factors introduced into host insects by endoparasitoid wasps are usually essential for successful parasitism. This includes polydnaviruses (PDVs) that are produced in the reproductive organ of female hymenopteran endoparasitoids and are injected, together with venom proteins, into the host hemocoel at oviposition. Inside the host, PDVs enter various tissue cells and hemocytes where viral genes are expressed, leading to developmental and physiological alterations in the host, including the suppression of the host immune system. Although several studies have shown that some PDVs are only effective when accompanied by venom proteins, there is no report of an active venom ingredient(s) facilitating PDV infection and/or gene expression. In this study, we describe a novel peptide (Vn1.5) isolated from Cotesia rubecula venom that is required for the expression of C. rubecula bracoviruses (CrBVs) in host hemocytes (Pieris rapae), although it is not essential for CrBV entry into host cells. The peptide consists of 14 amino acids with a molecular mass of 1598 Da. In the absence of Vn1.5 or total venom proteins, CrBV genes are not expressed in host cells and did not cause inactivation of host hemocytes.

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Elevated jasmonic acid (JA) concentrations in response to herbivory can induce wounded plants to produce defences against herbivores. In laboratory and field experiments we compared the effects of exogenous JA treatment to two closely related cabbage species on the host-searching and oviposition preference of the diamondback moth (DBM), Plutella xylostella. JA-treated Chinese cabbage (Brassica campestris) was less attractive than untreated Chinese cabbage to ovipositing DBM, while JA-treatment of common cabbage (B. oleracea) made plants more attractive than untreated controls for oviposition by this insect. Similar effects were observed when plants of the two species were damaged by DBM larvae. In the absence of insect-feeding, or JA application, Chinese cabbage is much more attractive to DBM than common cabbage. Inducible resistance therefore appears to occur in a more susceptible plant and induced susceptibility appears to occur in a more resistant plant, suggesting a possible balance mechanism between constitutive and inducible defences to a specialist herbivore.

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During oviposition, the parasitoid wasp Cotesia congregata injects polydnavirus, venom, and parasitoid eggs into larvae of its lepidopteran host.. the tobacco hornworm, Manduca sexta. Polydnaviruses (PDVs) suppress the immune system of the host and allow the juvenile parasitoids to develop without being encapsulated by host hemocytes mobilized by the immune system. Previous work identified a gene in the Cotesia rubecula PDV (CrV1) that is responsible for depolymerization of actin in hemocytes of the host Pieris rapae during a narrow temporal window from 4 to 8 h post-parasitization. Its expression appears temporally correlated with hemocyte dysfunction. After this time, the hemocytes recover, and encapsulation is then inhibited by other mechanism(s). In contrast, in parasitized tobacco hornworm larvae this type of inactivation in hemocytes of parasitized M. sexta larvae leads to irreversible cellular disruption. We have characterized the temporal pattern of expression of the CrV1-homolog from the C. congregata PDV in host fat body and hemocytes using Northern blots, and localized the protein in host hemocytes with polyclonal antibodies to CrV1 protein produced in P. rapae in response to expression of the CrV1 protein. Host hemocytes stained with FITC-labeled phalloidin, which binds to filamentous actin, were used to observe hemocyte disruption in parasitized and virus-injected hosts and a comparison was made to hemocytes of nonparasitized control larvae. At 24 h post-parasitization host hemocytes were significantly altered compared to those of nonparasitized larvae. Hemocytes front newly parasitized hosts displayed blebbing, inhibition of spreading and adhesion, and overall cell disruption. A CrV1-homolog gene product was localized in host hemocytes using polyclonal CrV1 antibodies, suggesting that CrV1-like gene products of C. congregata's bracovirus are responsible for the impaired immune response of the host. (C) 2005 Elsevier Ltd. All rights reserved.

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Postharvest senescence in broccoli (Brassica oleracea L. var Italica) florets results in phenotypic changes similar to those seen in developmental leaf senescence. To compare these two processes in more detail, we investigated molecular and biochemical changes in broccoli florets stored at two different temperatures after harvest. We found that storage at cooler temperatures delayed the symptoms of senescence at both the biochemical and gene expression levels. Changes in key biochemical components (lipids, protein, and chlorophyll) and in gene expression patterns occurred in the harvested tissue well before any visible signs of senescence were detected. Using previously identified senescence-enhanced genes and also newly isolated, differentially expressed genes, we found that the majority of these showed a similar enhancement of expression in postharvest broccoli as in developmental leaf senescence. At the biochemical level, a rapid loss of membrane fatty acids was detected after harvest, when stored at room temperature. However, there was no corresponding increase in levels of lipid peroxidation products. This, together with an increased expression of protective antioxidant genes, indicated that, in the initial stages of postharvest senescence, an orderly dismantling of the cellular constituents occurs, using the available lipid as an energy source. Postharvest changes in broccoli florets, therefore, show many similarities to the processes of developmental leaf senescence.

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Highly purified, intact chloroplasts were prepared from pea (Pisum sativum L.) and spinach (Spinacia oleracea L.) following an identical procedure, and were used to investigate the cupric cation inhibition on the photosynthetic activity. In both species, copper inhibition showed a similar inhibitor concentration that decreases the enzyme activity by 50% (IC(50) approximately 1.8 microM) and did not depend on the internal or external phosphate (Pi) concentration, indicating that copper did not interact with the Pi translocator. Fluorescence analysis suggested that the presence of copper did not facilitate photoinhibition, because there were no changes in maximal fluorescence (F(m)) nor in basal fluorescence (F(o)) of copper-treated samples. The electron transport through the photosystem II (PSII) was also not affected (operating efficiency of PSII-F'v/F'm similar in all conditions). Yet, under Cu(2+) stress, the proportion of open PSII reaction centers was dramatically decreased, and the first quinone acceptor (Q(A)) reoxidation was fully inhibited, as demonstrated by the constant photochemical quenching (q(P)) along experiment time. The quantum yield of PSII electron transport (Phi(PSII)) was also clearly affected by copper, and therefore reduced the photochemistry efficiency. Manganese, when added simultaneously with copper, delayed the inhibition, as measured by oxygen evolution and chlorophyll fluorescence, but neither reversed the copper effect when added to copper-inhibited plastids, nor prevented the inhibition of the Hill activity of isolated copper-treated thylakoids. Our results suggest that manganese competed with copper to penetrate the chloroplast envelope. This competition seems to be specific because other divalent cations e.g. magnesium and calcium, did not interfere with the copper action in intact chloroplasts. All results do suggest that, under these conditions, the stroma proteins, such as the Calvin-Benson cycle enzymes or others are the most probable first target for the Cu(2+) action, resulting in the total inhibition of chloroplast photosynthesis and in the consequent unbalanced rate of production and consumption of the reducing power.

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El estudio valor a el estado nutricional de las familias en las siguientes comunidades: Santa Cruz, Tisma Grande y la Montañita N o 2, pertenecientes al municipio de Masaya. Se inició con el análisis de sus patro nes de consumo, dando valor al aporte nut ricional de las plantas locales . En esta investigación cualit ativa se aplicaron los siguientes instrumentos : Entrevistas y recorr idos de fincas . De estos se derivan dos estudios de casos. El primero reflejó que los 9 patr ones de consumo poseen suficiencia en cuanto al acceso a alimentos nutritivos superando el 110%. El índice de di versidad de la dieta ( suficiencia ) en la semana, alcanza un rango de 0.89 en Tisma Grande, con valoración deficiente, en Santa Cruz de 0.92 con valoración aceptable y l a Montañita N o 2 de 1.08, con valoración adecuad a . En el aspecto de la diversidad de l a dieta en la semana , los resultados fuer on rangos promedios entre 9.3 y 9.7 significando la existencia de una diver sidad de dieta aceptable. El segundo estudio de caso refleja info rmac ión sobre los tipos de plantas locales con valor nutritivo y las formas de consumo diario determina n do así las siguientes plantas: Espinaca ( Spinacia oleracea ), Quelite ( Amaranthus hybridus ), Espadillo ( Yucca elephantipes ), Verdolaga ( Portulaca olerac ea ), Mora ( Morus nigra), Cojombro (Sicana odorífera), Batata (Ipomoea batatas), Piñuela (Bromelia baratas), Panamá (Sterculia apetala, Tempisque (Sideroxylon capiri), Caimito (Chrysophyllum cainito) entre otras . Definitivamente , podemos detallar que las f amilias consumen alimentos con mayo r aporte calórico que proteínico, ya que consumen alimentos derivados de los lácteos, car nes y dulces. Sin embargo, es importante mencion ar que esto no indica que exista una mala calidad nu tricional en las familias, puest o que el consumo de proteínas no es tan defi ci ente, por eso hace necesario incluir a limentos que permitan compleme ntar el consumo de proteínas al organismo de las familias, logrando así un a dieta balanceada que les permita a las familias mejorar sus condic iones de salud y de vida satisfaciendo así sus necesidades nutricionales diarias en relación al tr ab ajo que realizan día a día en sus pequeñas parcelas productivas.

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Cauliflower (Brassica oleracea var. botrytis) is a vernalization-responsive crop. High ambient temperatures delay harvest time. The elucidation of the genetic regulation of floral transition is highly interesting for a precise harvest scheduling and to ensure stable market supply. This study aims at genetic dissection of temperature-dependent curd induction in cauliflower by genome-wide association studies and gene expression analysis. To assess temperature dependent curd induction, two greenhouse trials under distinct temperature regimes were conducted on a diversity panel consisting of 111 cauliflower commercial parent lines, genotyped with 14,385 SNPs. Broad phenotypic variation and high heritability (0.93) were observed for temperature-related curd induction within the cauliflower population. GWA mapping identified a total of 18 QTL localized on chromosomes O1, O2, O3, O4, O6, O8, and O9 for curding time under two distinct temperature regimes. Among those, several QTL are localized within regions of promising candidate flowering genes. Inferring population structure and genetic relatedness among the diversity set assigned three main genetic clusters. Linkage disequilibrium (LD) patterns estimated global LD extent of r(2) = 0.06 and a maximum physical distance of 400 kb for genetic linkage. Transcriptional profiling of flowering genes FLOWERING LOCUS C (BoFLC) and VERNALIZATION 2 (BoVRN2) was performed, showing increased expression levels of BoVRN2 in genotypes with faster curding. However, functional relevance of BoVRN2 and BoFLC2 could not consistently be supported, which probably suggests to act facultative and/or might evidence for BoVRN2/BoFLC-independent mechanisms in temperature regulated floral transition in cauliflower. Genetic insights in temperature-regulated curd induction can underpin genetically informed phenology models and benefit molecular breeding strategies toward the development of thermo-tolerant cultivars.

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Este artículo informa sobre la valoración de la fitotóxicidad del Material Particulado Sedimentable (MPS) en la zona urbana del cantón Cuenca. El MPS se recolectó en tres sitios de la zona urbana, mediante el método descrito en el Texto Unificado de Legislación Ambiental Secundaria del Ministerio del Ambiente (TULASMA). Por el material particulado se realizó la determinación de la concentración de los componentes utilizando el análisis gravimétrico, la de los metales pesados por espectroscopía de absorción atómica, y la de aniones por método adaptado de referencia EPA 300.1. Posteriormente se evaluó su fitotóxicidad en cuatro especies, mediante el bioensayo de germinación y elongación de raíz e hipocótilo, en semillas de Lactuca sativa, Brassica oleracea itálica, Allium cepa y Raphanus sativus. En el bioensayo las semillas se expusieron a diferentes diluciones de la suspensión acuosa de MPS. Los resultados muestran que el efecto de los MPS dependió de la concentración y de la especie analizada, evidenciando diferentes grados de fitotóxicidad.

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Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - UL

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O boro (B) é um dos micronutrientes mais importantes na cultura da couve flor (Brassica oleracea) sendo a sua deficiência comum nesta espécie, causando sintomas característicos e severos, inviabilizando em alguns casos a produção de inflorescências comercializáveis. De maneira geral, a couve-flor responde à adubação boratada e a intensidade da resposta esta relacionada ao teor do nutriente no solo, tipo de solo e a cultivar. Com o objetivo de avaliar o efeito da adubação com fontes e doses de B via solo na cultura da couve-flor, foi realizado um experimento em ambiente protegido na Universidade Estadual de Londrina (UEL). O delineamento experimental utilizado foi inteiramente casualisado com quatro repetições num fatorial 4 x 2, sendo quatro doses de B (0; 0,5; 1,0 e 2,0 mg kg-1) e duas fontes de B [ácido bórico (17% de B) e Solubor® (21% de B)]. A semeadura da cultivar Piracicaba Precoce foi realizada em vasos de 3,0 L preenchidos com solo. Antes da semeadura foi realizada a calagem para elevar a saturação por bases a 70%. A adubação de semeadura foi realizada com uma solução completa N (150 mg L-1), P K (100 mg L-1), Cu (1,5 mg L-1), Zn (5 mg L-1) e Fe Mn (2,5 mg L-1). A adubação com B foi realizada no solo via solução logo após a semeadura. A adubação com N e K foi parcelada, sendo ½ na semeadura e ½ em cobertura aos 15 dias após a semeadura. Avaliou-se o teor de clorofila, determinado indiretamente no terço médio da folha mais desenvolvida, aos 45 dias após a semeadura, por meio de leituras SPAD com auxílio de um clorofilômetro digital (Minolta 502). Os maiores teores de clorofila nas folhas de couve flor foram observados na aplicação de ácido bórico, entretanto, não houve diferença significativa entre as doses de B. Conclui-se que independente da dose de B, a adubação com boro via solo na forma de ácido bórico aumentou o teor de clorofila das folhas de couve flor Piracicaba Precoce.