958 resultados para Arenaria, seeds


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The objective of this work was to develop a methodology for seed processing and X-ray analysis and to study imbibition pattern in seeds of candeia (Eremanthus incanus). Seeds were gathered in 2001 and 2002 in Morro do Pilar and Lavras respectively, processed and stored in a cold chamber (5ºC/60%RH) until the start of experiments. In order to identify unfilled seeds, a protocol was developed for X-ray use combining radiation energy (Kv) and exposure time (seconds). For elimination of unfilled seeds, an experiment was conducted using a South Dakota seed blower whereby different opening settings and ventilation times were combined. Original seed lots and categorized lots following radiograph viewing were tested by germination tests, with seeds being cleansed in sodium hypochlorite and scattered over blotting paper in 'gerboxes' and then taken to germinators with alternating temperatures of 20º-30ºC and 10 hours of light, for up to 15 days. Imbibition curves were determined under the conditions 30ºC, 20º-30ºC/10 hours of light and 30º-20ºC/10 hours of light. The X-ray protocol that best allowed viewing of internal seed structures was 30Kv for 45 seconds. Seed separation using the blower setting at a 3.0 opening for 30 seconds raised the number of embryonic seeds to values exceeding 99%, also raising the germination rates as a consequence. The imbibition pattern is three-phased and the germination process is completed in 72 hours. Under alternate temperatures, primary root growth is favored.

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A espécie vegetal, Petroselinum sativum Hoff, conhecida como salsa, é amplamente utilizada na medicina popular brasileira como diurético. O objetivo desse estudo é verificar se o uso brasileiro do extrato aquoso da salsa tem efeitos semelhantes com investigações que mostram o efeito diurético da P. sativum em ratos. MÉTODOS: 19 Ratos foram anestesiados e canulamos a traquéia, artéria carótida esquerda (para a medição da pressão arterial) e bexiga urinária (para coletar urina). Depois de 40 minutos para adaptação das condições cirúrgicas, ratos anestesiados foram administrados de acordo com seus grupos: controle (CON), administração oral com 1.0 mL de água filtrada, e grupo tratado (AE), administração oral com extrato aquoso de sementes de salsa 20% (AE). Urina foi coletada três vezes (de 30 em 30 minutos) e então esse material foi utilizado para determinações de sódio e potássio, para avaliar a quantidade excretada desses íons. Pressão arterial foi medida pelo manômetro de mercúrio por 9 vezes. Todos os dados foram estatisticamente avaliados. RESULTADOS E CONCLUSÃO: nos parâmetros anestesiados, o grupo CON não mostrou nenhuma diferença; mas o grupo AE mostrou um aumento do fluxo urinário e da quantidade excretada de sódio e potássio, e também uma diminuição da pressão arterial. Todos os parâmetros apresentaram essas modificações após 30 minutos de administração do AE (p<0,05). Esses resultados mostram que o tratamento com o AE leva a efeitos natriurético e hipotensor em ratos Wistar anestesiados, confirmando o uso da população brasileira dessa erva como diurético.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Osmotic potentials on water uptake and germination of Guazuma Ulmifolia Lam. (Sterculiaceae) seeds. This work was carried out in the Germination Lab. of the Department of Botany, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, São Paulo State, Brazil. The aims of this work were to determine the water uptake curve and to evaluate the germination of Guazuma ulmifolia seeds subjected to different water potentials. For the water uptake curve, seven replicates of 50 pre-scarified seeds were placed onto paper moistened with 15 mL PEG 6000 solution under the potentials 0 (control), -0.3 and -0.6 MPa at 25o C in the darkness. For the germination assay, four replicates of 50 seeds were subjected to the same above-described conditions; however, one lot of seeds was modified when there was variation in the refractometric index, whereas the remaining ones were kept in the same solutions until the end of the experiment. All three phases of water uptake were detected under 0 and -0.3 MPa; however, phase II was prolonged under -0.6 MPa and germination was not observed. For 0 and -0.3 MPa, the adopted statistical models consisted of asymptotic (phases I and II) and exponential (phase III) functions, y = a*[1 - b*exp (-c*t) + exp (-d + e*(t - t0)]. For -0.6MPa, only the asymptotic function y = a* [1 - b* exp (-c*t)] was used since there was no evidence of germination. The germination final percentage and speed index were lower under -0.3 MPa, mainly when solutions were not replaced; besides, germination was not detected under -0.6 MPa, with or without solution replacement.

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The purpose of treating seeds chemically is to eradicate their pathogens and/or protect them against soil pathogens, mainly by germination time. However, there is little research on vegetables investigating the effect of this treatment on seed quality. Therefore, this study evaluates the effects of Carboxin + Thiram doses on germination and vigor of three lots of broccoli seeds, as well as on the incidence of fungi in treated seed. The 15 treatments were evaluated in a factorial system (3x5), with the first factor consisting of three lots of 'Avenger' broccoli seeds (lots 82744, 82745 and 82749), and the second factor consisting of five doses (0, 0.04, 0.06, 0.10 and 0.12% of a.i.) of Carboxin + Thiram fungicide (commercial name Vitavax-Thiran). The germination and seed vigor were evaluated, in addition to the presence of pathogens in seeds after treatment (blotter test). All lots showed high levels of germination and vigor. The lot 82749, however, showed higher value in plug test in substrate emergence (99%) than lot 82745 (95%). Regarding the treatment with Carboxin + Thiram, no changes in germination average (98%) and vigor were noticed (average for the first germination count, length, and dry weight of seedling, plug test at 10 days after sowing of 97%, 4.9 cm, 4.0 mg and 96%, respectively), showing that this fungicide, in the evaluated doses, does not affect the quality of broccoli seeds. As to seeds health, the pathogens Alternaria spp. and Fusarium spp. were detected, in addition to saprophytic species such as Penicillium, Aspergillus, Trichoderma, and Rhizopus. The higher incidence of Fusarium spp. was noticed in lot 82744, and the lowest in lot 82749. As to Penicillium spp., lot 82479 was the most contaminated. Regarding other fungi, the general incidence was very low and there was no difference between lots and doses used.

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Aims: This work aimed to assess how seed size, vials, vial sealing (in vitro), and substrate (in vivo) affect C. regium germination and emergence. This study shall contribute to the viable production of C. regium seedlings. Study Design: The experimental design used in these experiments was randomized. Place and Duration of Study: Department of Plant Biotechnology, Universidade de RibeirãoPreto, between March 2010 and December 2010. Methodology: This work has evaluated how seed size, vials, vial sealing (in vitro), and substrate (in vivo) influence the germination and emergence of C. regium. Results: The results showed that cultivation of C. regium seedlings from seeds is viable, irrespective of seed size. Vial oxygenation is an important parameter to consider in vitro, to obtain a larger number of normal seedlings. As for in vivo conditions, germination should be conducted in sand, to ensure a greater amount of young seedlings. Conclusion: The results presented here attested that it is possible to produce C. regium seedlings from seeds of any size both in vivo and in vitro conditions. In vitro, it is important to consider vial oxygenation, in order to obtain a greater amount of normal seedlings. In vivo, germination should be conducted in sand, to ensure production of a large quantity of seedlings.

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Liming is indispensable in acid soils for amending acidity; however, the technique may alter the cation balance in soil and, consequently, may limit the availability and uptake of nutrients. We aimed to evaluate different molar ratios between calcium (Ca) and magnesium (Mg) on the availability of soil nutrients and their influence on the productive properties of sunflower and seed quality. The experiment was carried out in a greenhouse under two types of contrasting soils and six molar combinations of CaCO3and MgCO3 in amendment of soil acidity to raise base saturation to 70%. After incubation, soil analysis was undertaken to verify the ratios obtained and nutrient availability. Morphological and production variables were analyzed at the end of the experiment, as well as accumulation of nutrients in the achenes and their physiological quality. In spite of equal base saturation between the types of soil, there were differences in the available contents of these cations. The increase in the Ca contents limited the Mg contents to the critical level of the sunflower. This result had a negative influence on the production properties of sunflower and physiological quality. In contrast, there was a compensation of the crop with greater accumulation of nutrients in the achenes under lower yield.

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In Maize (Zea maize L.), cost of hybrid seed production is directly related to the yield and quality of seed obtained per hectare of female parent. It is also important to consider the effects that a male parent can exert on the development of hybrid seed in the female parent. This effect is known as xenia. The objectives of this study were to evaluate xenia effects on 1) yield as 80K units, 2) germination of the hybrid seed and 3) susceptibility of the hybrid seed to mechanical damage. One female inbred and four male inbred lines were selected from a parent list of hybrids. The experiment was designed to allow individual cross pollination between each male inbred and the female inbred line. For use as a control, the female inbred was allowed to self pollinate. Experiments were conducted in Illinois and Iowa during 2008 and 2009 and in Nebraska during 2009. A significant inbred effect was detected on yield as 80k (α=0.001). The selfed female and pollination with male inbred B resulted in lower yields of hybrid seed. For germination, a significant inbred effect was detected (α=0.001), but was due to lower germination percentage of seed produced on the selfed female. All hybrid combinations resulted in higher germination percentages with no significant differences among hybrids. The inbred x mechanical damage interaction was significant (P=0.04) for effects on cold saturated soil germination tests. Use of inbred B resulted in a two-percentage-point reduction in cold germination when treated with the impact simulator. In a maize seed company, the production research group provides yield estimates for production of new hybrid combinations. Results from this study indicate that using only the female inbred yield may provide inaccurate estimates. Therefore to improve yield estimation, experiments should be designed to include male inbreds. Male inbreds can also impart a negative effect to the hybrid seed on tolerance to mechanical damage, thus lowering quality and increasing seed discard. When testing for hybrid seed germination, there is no need to consider distinct hybrid combinations. Female inbreds can be grown in open-pollinated fields to avoid loss of vigor observed with selfing. Advisor: George Graef

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Ethanol extracts of powdered genipap (Genipa americana L), umbu (Spondia tuberosa A.) and siriguela (Spondia purpurea L) prepared from separate pulp, seeds and peel were investigated for their (i) antioxidant capacity, which was evaluated by various known methods; (ii) acetylcholinesterase (AChE) inhibitory activity; and (iii) cytotoxic effect on corneal epithelial cells of sheep. The highest values of total phenolic content were obtained with peel and seed extracts. Siriguela and umbu (seeds and peel) extracts displayed the highest antioxidant activities. Lipid peroxidation assays using mimetic biomembranes and mouse liver homogenates indicated that genipap pulp is a promising antioxidant. The investigation of phenols and organic acid contents revealed the presence of quercetin, citric and quinic acids, chlorogenic acid derivatives, among others, in several extracts, with the highest amount found in siriguela seeds. Genipap pulp and siriguela seed ethanol extracts presented an AChE inhibition zone similar to that of the positive control, carbachol. AChE inhibition assay with chlorogenic acid, one of the main constituents of siriguela seeds, revealed that this acid showed activity similar to that of the control physostigmine. These data suggest that these extracts are potentially important antioxidant supplements for the everyday human diet, pharmaceutical and cosmetic industries. (C) 2012 Elsevier Ltd. All rights reserved.

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This clinical randomized trial was performed with the objective to evaluate the stress levels of the nursing staff of a hospital and analyze the effectiveness of auriculotherapy with needles and seeds. The 75 participants with mean (44/58.7%) and high (31/41.3%) scores according to the Stress Symptoms List were divided into groups (control, needles, and seeds), who received eight sessions on the Shenmen, Kidney and Brainstem points and were evaluated at the baseline, fourth and eighth sessions and on the 15-day follow-up session. The analysis of variance (ANOVA) showed significant differences among the groups at the third assessment (F=3.963/P=0.023) and follow-up (F=6.136/P=0.003). These differences occurred between the control and needle groups. The 'seeds' and needles groups both showed differences (p < 0.05) at the second assessment when compared within the same group. In conclusion, auriculotherapy reduced the stress in the nursing staff, with needles showing better results than seeds for high scores, maintaining the effects for 15 days.

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This work aimed to evaluate the influence of different concentrations of Zantedeschia aethiopica Spreng. extract on the physiological performance of the seed and on the response of the antioxidant metabolism of lettuce seedlings. The treatments consisted of leaves extracts from Z. aethiopica at concentrations of 0, 6, 12, 25 and 50%. Germination, first germination count, germination speed and index, length of shoot and radicle, seedling total dry mass, chlorophyll content, activity of superoxide dismutase, catalase and ascorbarte peroxidase enzymes, lipid peroxidation, hydrogen peroxide quantification and seedling emergence, length of organs, and total dry mass of seedlings were evaluated. The percentage of germination, the length of the shoot and radicle of seedlings and the total dry mass of seedlings grown in the greenhouse were reduced as the concentration of the extract increased. There were increases of electrical conductivity, of superoxide dismutase, catalase and ascorbate peroxidadase enzymes and the amount of hydrogen peroxide and lipid peroxidation in seedlings with increasing extract concentration. The extract reduced the physiological quality of lettuce seeds and induced an increased production of hydrogen peroxide in seedlings, which increased the activity of antioxidant enzymes that were not effective in tissue detoxification, resulting in cellular damage and increased numbers of abnormal seedlings.

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Eggplant seeds germination can be slow and uneven, justifying the use of pre-germinative treatments to improve the performance of seed lots. One option of treatment is the controlled hydration of seeds by priming. In this way, this study aimed to evaluate the performance of eggplant seeds cv. Embu submitted to different methodologies of priming. The seeds used in the experiment were stored in cold chamber (15 degrees C and 55% RH) in paper bags. The research was carried out at Central Laboratory of Seeds/UFLA. The seeds were submitted to the priming in aerated solutions varying the following factors: temperature (15 degrees C and 25 degrees C), time (24, 48 and 72 hours) and solution (water, PEG, KNO3 and PEG+KNO3). Seeds were washed in running water and dried at 30 degrees C, until the return to the initial moisture content, around 10%. The variables analyzed were percentage of germination, percentage of emergence, speed index of emergence and electrical conductivity. The treatments were arranged in a completely randomized design, according to a factorial arrangement 2x3x4+1 (control - seeds without priming). The results showed that priming improves the vigour of eggplant seeds with no effect on viability; the priming in water or KNO3 is efficient to improve the seed vigour and priming in water or KNO3 may use temperature of 15 degrees C or 25 degrees C for 24, 48 or 72 hours.

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The present study investigated the germination and vigor of Caesalpinia echinata (Brazilwood) seeds stored at negative temperatures. Recently harvested seeds were cryopreserved at -18 degrees or -196 degrees C and periodically evaluated for germination, seed vigor and carbohydrate composition. The temperatures did not influence the germination percentages or vigor. The germination percentage decreased from 88% in recently harvested seeds to 60% after 730 days of storage. The different temperature and storage times tested did not affect the vigor seed germination as indicated by the measures of plant growth and survival. The different temperatures used did not cause changes in the carbohydrate composition. The tegument cell walls were rich in lignin, arabinose and xylose. The cytoplasm of the cotyledons and embryos had high levels of glucose, fructose, and sucrose. The cryopreservation technique here presented was effective in the conservation of Brazilwood seeds for the medium term.

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The fine particles serving as cloud condensation nuclei in pristine Amazonian rainforest air consist mostly of secondary organic aerosol. Their origin is enigmatic, however, because new particle formation in the atmosphere is not observed. Here, we show that the growth of organic aerosol particles can be initiated by potassium-salt-rich particles emitted by biota in the rainforest. These particles act as seeds for the condensation of low- or semi-volatile organic compounds from the atmospheric gas phase or multiphase oxidation of isoprene and terpenes. Our findings suggest that the primary emission of biogenic salt particles directly influences the number concentration of cloud condensation nuclei and affects the microphysics of cloud formation and precipitation over the rainforest.