929 resultados para Propagation and acclimatization


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The objective of this work was to establish an efficient protocol for in vitro multiplication and rooting, as well as ex vitroacclimatization of Aegiphila verticillata, a woody species found in Brazilian rocky fields. Aseptic cultures were established by seeds and two multiplication analyses were performed. In the first, we employed 6-benzylaminopurine (BAP – 0, 2.5, 5 and 7.5 μM) + α-naphthalene acetic acid (NAA – 0, 0.2, 0.4 and 0.6 μM) and, in the second, were studied adenine sulfate, kinetin and thidiazuron (0, 5, 7.5, 10 and 12.5 μM). After 90 days, we assessed the quantitative and qualitative shoot propagation. There were more than 90% seed germination and low contamination (2%). In multiplication phase, the culture medium that promoted the best quantitative and qualitative culture development was supplemented with 7.5 μM BAP + 0.4 μM NAA. In the rooting assay, were used NAA, indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) (0, 0.1, 0.2, 0.3 or 0.4 μM). After 90 days, the root number and rooting quality were evaluated. In this analysis, differences were not found between the control and the other treatments. Rooted plantlets were acclimatized in styrofoam trays for 30 days, after which they were transferred to pots in the greenhouse. Only 3% of the plants subjected to initial acclimatization died and 70% of the plants transferred to the field conditions survived and showed normal development. The results founded in this work are the first involving in vitro propagation and ex vitroacclimatization of Aegiphila verticillata and provide a continuous supply of this medicinal native species, endangered due anthropogenic activities.

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El problema: La flora nativa de Córdoba, actualmente amenazada, es rica en especies con potencial ornamental que todavía no se cultivan. El uso de estas plantas está limitado por la escasez de material biológico, la falta de conocimientos de su propagación y su insuficiente valoración pública. Hipótesis: La propagación y el cultivo de una amplia gama de plantas nativas cordobesas con potencial ornamental son técnicamente factibles y tienen potencial productivo y económico. Objetivo: Promover el uso de especies nativas ornamentales en la provincia de Córdoba. Objetivos específicos: 1. Desarrollar metodologías de propagación y cultivo de especies nativas con potencial ornamental; 2. Transferir estas metodologías a viveros privados y públicos; 3. Difundir los conocimientos obtenidos a instituciones educativas. Métodos: 1- Colección: Se realizarán viajes de campo para obtener semillas o esquejes de al menos 6 especies nativas seleccionadas. Las semillas se limpiarán y se conservarán en frío. 2- Propagación: En la primavera se sembrarán 100 semillas por especie, accesión y tratamiento; se registrará porcentaje y tiempo de germinación. Los plantines se trasplantarán a almácigos, se registrará supervivencia y crecimiento. Para la propagación vegetativa, se trasplantarán esquejes de estolones directamente a macetas. 3- Trasplante: En verano, los plantines se trasplantarán a macetas grandes; se registrará supervivencia y crecimiento durante un año. 4- Documentación: Se elaborarán protocolos de las metodologías adecuadas para la propagación de las especies, usos ornamentales y características relevantes. 5- Transferencia: Los protocolos, muestras de semillas y de plantas, se transferirán a dos viveros que se comprometan a continuar con el cultivo de las especies. 6- Difusión: Se realizarán cursos, talleres, charlas y pasantías para dar a conocer la propagación de plantas nativas en instituciones educativas, desde la primaria hasta la universidad. Resultados y productos esperados: 1- Protocolos de propagación de al menos 6 especies nativas ornamentales y su transferencia a viveros, como base de una actividad productiva novedosa. 2- Un aporte a la conservación ex situ y el uso sostenible de la flora nativa. 3- Una mayor valoración de esta en la comunidad educativa. Importancia: 1- Desarrollo de la producción de plantas nativas con valor ornamental, como una alternativa económica. 2- Conservación ex situ y uso sostenible de la flora nativa. 3- Difusión del conocimiento del valor ornamental de las nativas. 4. Información científica de la biología y ecología de especies nativas. Pertinencia: Productos (ver Resultados). El impacto inmediato esperado es un aumento en la propagación, la producción, la demanda, la comercialización y el uso de plantas ornamentales nativas. Se espera también la generación de nuevos conocimientos y el estímulo de líneas de investigación biológicas y agronómicas.

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We analyse the variations produced on tsunami propagation and impact over a straight coastline because of the presence of a submarine canyon incised in the continental margin. For ease of calculation we assume that the shoreline and the shelf edge are parallel and that the incident wave approaches them normally. A total of 512 synthetic scenarios have been computed by combining the bathymetry of a continental margin incised by a parameterised single canyon and the incident tsunami waves. The margin bathymetry, the canyon and the tsunami waves have been generated using mathematical functions (e.g. Gaussian). Canyon parameters analysed are: (i) incision length into the continental shelf, which for a constant shelf width relates directly to the distance from the canyon head to the coast, (ii) canyon width, and (iii) canyon orientation with respect to the shoreline. Tsunami wave parameters considered are period and sign. The COMCOT tsunami model from Cornell University was applied to propagate the waves across the synthetic bathymetric surfaces. Five simulations of tsunami propagation over a non-canyoned margin were also performed for reference. The analysis of the results reveals a strong variation of tsunami arrival times and amplitudes reaching the coastline when a tsunami wave travels over a submarine canyon, with changing maximum height location and alongshore extension. In general, the presence of a submarine canyon lowers the arrival time to the shoreline but prevents wave build-up just over the canyon axis. This leads to a decrease in tsunami amplitude at the coastal stretch located just shoreward of the canyon head, which results in a lower run-up in comparison with a non-canyoned margin. Contrarily, an increased wave build-up occurs on both sides of the canyon head, generating two coastal stretches with an enhanced run-up. These aggravated or reduced tsunami effects are modified with (i) proximity of the canyon tip to the coast, amplifying the wave height, (ii) canyon width, enlarging the areas with lower and higher maximum height wave along the coastline, and (iii) canyon obliquity with respect to the shoreline and shelf edge, increasing wave height shoreward of the leeward flank of the canyon. Moreover, the presence of a submarine canyon near the coast produces a variation of wave energy along the shore, eventually resulting in edge waves shoreward of the canyon head. Edge waves subsequently spread out alongshore reaching significant amplitudes especially when coupling with tsunami secondary waves occurs. Model results have been groundtruthed using the actual bathymetry of Blanes Canyon area in the North Catalan margin. This paper underlines the effects of the presence, morphology and orientation of submarine canyons as a determining factor on tsunami propagation and impact, which could prevail over other effects deriving from coastal configuration.

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Rooting and acclimatization are limiting steps in plant micropropagation, especially in woody plant species. This study aimed to evaluate the IAA and IBA effect on the in vitro rooting and acclimatization of micropropagated shoots of Japanese plum (Prunus salicina Lindl.) cv. América. Shoots from 3 to 4 cm long were inoculated in MS medium with half salt and vitamin concentrations (MS/2) added with IAA and IBA (0, 0.25, 0.5, 0.75 and 1 mg L-1). After a 20-day period in in vitro cultivation, the shoots were evaluated, and then transferred to a greenhouse, and evaluated after 30 days. At the end of the in vitro cultivation period, no significant interactions were observed for number of roots per shoot and rooting percentage, but a significant effect was recorded for auxin type only, for which shoots grown in media added with IBA showed high values - 0.87 and 41.95%, respectively. A linear increase response from 1.45 to 5.75 cm was verified for root length of shoots cultivated in IBA medium; however, no significant effect was observed, and a 0.86 cm average root length per shoot grown in medium added with IAA was found. After 30 days of acclimatization period, the largest survival percentage was obtained from shoots cultivated in medium with 1 mg L-1 of IBA and IAA (88% and 92%, respectively). Although, IBA provided the highest in vitro rooting, most of the surviving shoots were those originated in IAA-added medium, probably because IBA promoted longer fibrous roots, less appropriate for transplant and soil fixation, as they are easily damaged. It was concluded that in vitro rooting with the addition of the highest IAA concentration (1 mg L-1) provided the greatest plant survival during the acclimatization period of the Japanese plum cv. América.

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Fruits and almond from the dendezeiro, oil palmbelonging to the Elaeis genus,are widely used for the production of cookingoils or for the pharmaceutical and cosmetic industries.In the last decade, this oil palm also emerged as a promising source for commercialbiofuel production. This study evaluated the effect of different culture media, MS (MURASHIGUE AND SKOOG) and Y3 (EEUWENS)and carbohydrates duringin vitro germination of zygotic embryos, the effect of growth regulators GA3, NAA and BA Ponin vitro seedling development, and the survival rate of acclimatized seedlingsof Manicoré hybrid (Elaeis oleifera x E. guineensis). Zygotic embryos were inoculated on MS and modified Y3 media, supplemented with different sucrose concentrations (30, 45, and 60 gL-1) or sorbitol (36 gL-1), and the germination rate was evaluated after 30 days. Subsequently, seedlings were transferred to modified Y3 culture medium supplemented with differentGA3 concentrations (3.5 and 7 mgL-1) or without it, combined or not with 1 mgL-1 of NAA, 5 mgL-1 of BAP.The highest germinationpercentage of germinated embryos (92%) was observed in MS medium supplemented with 36 gL-1 sorbitol. Culture media supplemented with growth regulatorsGA3, NAA and BAP promoted greater shoot lengththan control media. Rooted seedlings showed high survival percentage (85%) during acclimatization.

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Icewine is an intensely sweet, unique dessert wine fennented from the juice of grapes that have frozen naturally on the vine. The juice pressed from the frozen grapes is highly concentrated, ranging from a minimum of 35° Brix to approximately 42° Brix. Often Icewine fennentations are sluggish, taking months to reach the desired ethanol level, and sometimes become stuck. In 6 addition, Icewines have high levels of volatile acidity. At present, there is no routine method of yeast inoculation for fennenting Icewine. This project investigated two yeast inoculum levels, 0.2 gIL and 0.5 gIL. The fennentation kinetics of inoculating these yeast levels directly into the sterile Icewine juice or conditioning the cells to the high sugar levels using a step wise acclimatization procedure were also compared. The effect of adding GO-FERM, a yeast nutrient, was also assessed. In the sterile fennentations, yeast inoculated at 0.2 gIL stopped fennenting before the required ethanol level was achieved, producing only 7.8% (v/v) and 8.1 % (v/v) ethanol for the direct and conditioned inoculations, respectively. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 12.2% (v/v) ethanol, whereas the direct inoculum produced 10.5% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the rate of biomass accumulation, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was no significant difference in acetic acid concentration in the final wines across all treatments. Fennentations using unfiltered Icewine juice at the 0.5 gIL inoculum level were also compared to see if the effects of yeast acclimatization and micronutrient addition had the same impact on fennentation kinetics and yeast metabolite production as observed in the sterile-filtered juice fennentations. In addition, a full descriptive analysis of the finished wines was carried out to further assess the impact of yeast inoculation method on Icewine sensory quality. At 0.5 gIL, the stepwise conditioned cells fennented the most sugar, producing 11.5% (v/v) ethanol, whereas the direct inoculum produced 10.0% (v/v) ethanol. The addition of the yeast nutrient GO-FERM increased the peak viable cell numbers, but reduced the ethanol concentration in wines fennented at 0.5 gIL. There was a significant difference 7 in acetic acid concentration in the final wines across all treatments and all treatments affected the sensory profiles of the final wines. Wines produced by direct inoculation were described by grape and raisin aromas and butter flavour. The addition of GO-FERM to the direct inoculation treatment shifted the aroma/flavour profiles to more orange flavour and aroma, and a sweet taste profile. StepWise acclimatizing the cells resulted in wines described more by peach and terpene aroma. The addition of GO-FERM shifted the profile to pineapple and alcohol aromas as well as alcohol flavour. Overall, these results indicate that the addition of GO-FERM and yeast acclimatization shortened the length of fermentation and impacted the sensory profiles of the resultant wines.

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Since dwarf napiergrass (Pennisetum purpureum Schumach.) must be propagated vegetatively due to lack of viable seeds, root splitting and stem cuttings are generally used to obtain true-to-type plant populations. These ordinary methods are laborious and costly, and are the greatest barriers for expanding the cultivation area of this crop. The objectives of this research were to develop nursery production of dwarf napiergrass in cell trays and to compare the efficiency of mechanical versus manual methods for cell-tray propagation and field transplanting. After defoliation of herbage either by a sickle (manually) or hand-mowing machine, every potential aerial tiller bud was cut to a single one for transplanting into cell trays as stem cuttings and placed in a glasshouse over winter. The following June, nursery plants were trimmed to a 25–cm length and transplanted in an experimental field (sandy soil) with 20,000 plants ha^(−1) either by shovel (manually) or Welsh onion planter. Labour time was recorded for each process. The manual defoliation of plants required 44% more labour time for preparing the stem cuttings (0.73 person-min. stemcutting^(−1)) compared to using hand-mowing machinery (0.51 person-min. stem-cutting^(−1)). In contrast, labour time for transplanting required an extra 0.30 person-min. m^(−2) (14%) using the machinery compared to manual transplanting, possibly due to the limited plot size for machinery operation. The transplanting method had no significant effect on plant establishment or plant growth, except for herbage yield 110 days after planting. Defoliation of herbage by machinery, production using a cell-tray nursery and mechanical transplanting reduced the labour intensity of dwarf napiergrass propagation.

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Local belief propagation rules of the sort proposed by Pearl(1988) are guaranteed to converge to the optimal beliefs for singly connected networks. Recently, a number of researchers have empirically demonstrated good performance of these same algorithms on networks with loops, but a theoretical understanding of this performance has yet to be achieved. Here we lay the foundation for an understanding of belief propagation in networks with loops. For networks with a single loop, we derive ananalytical relationship between the steady state beliefs in the loopy network and the true posterior probability. Using this relationship we show a category of networks for which the MAP estimate obtained by belief update and by belief revision can be proven to be optimal (although the beliefs will be incorrect). We show how nodes can use local information in the messages they receive in order to correct the steady state beliefs. Furthermore we prove that for all networks with a single loop, the MAP estimate obtained by belief revisionat convergence is guaranteed to give the globally optimal sequence of states. The result is independent of the length of the cycle and the size of the statespace. For networks with multiple loops, we introduce the concept of a "balanced network" and show simulati.

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

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The scope of this work was to compare two systems for vegetative propagation: conventional one (from cut stems) and in vitro micropropagation from axillary buds. Nodal segments (1 cm) of Mikania glomerata were used as explants. The experiments were evaluated in relation to number of shoots; % of rooting; number of roots and total fresh weight. Multiple shoots developed in MS containing 0.5 mg/L BAP. Rooting was induced in the presence of 1.0 mg/L IBA. Stems with five buds and one pair of leaves were the most appropriate for the production of cuttings. The time necessary for developing a protocol for the production of M. glomerata micropropagated plantlets was 6 months, whereas only half time was required to produce plantlets from stem cuttings. The greatest problem met during micropropagation was the culture contamination by endophytic bacteria and fungi.

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The aim of this study was to investigate whether handling and acclimatization could affect the biomarker responses in oysters Crassostrea gigas. Adult oysters were sampled in a farming area, subjected to handling stress during two hours (shell cleaning and transport), and then acclimatized in laboratory for 2, 3 and 4 weeks. Groups of five oysters were sampled before and after the handling (T0 and T1, respectively), and after 2, 3 and 4 weeks acclimatization. During the acclimatization, water was renewed daily, food given twice a day and temperature and salinity maintained at 22 °C and 25 ppt, respectively. One group, in another tank, was kept in similar conditions and was exposed for 1 week to 0.1 % diesel after the 2-weeks acclimatization period. After exposure, gills were immediately frozen in liquid N 2 for biochemical analyses. Higher expression of heat-shock proteins (HSP70) was observed after handling, and after acclimatization periods of 3-week and 4-week, compared to the T0 group. The diesel exposed group did not show elevated levels of HSP70, when compared to the 3-week acclimatized group. The activity of glutathione S-transferase (GST) was unchanged after handling, but was lower after all acclimatization periods, compared to the T0 group. Exposure to diesel caused an increase in GST activity compared to the 3-week acclimatized group, but not compared to T0. The activity of catalase (CAT), acetylcholinesterase (AChE), and the MDA levels remained unchanged during the whole experiment. These results point to the need of a special care in laboratory and field experiments employing HSP70 and GST as biomarkers. (Supported by CNPq-CTPetro to ACDB.). © 2008 Published by Elsevier Ltd.