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排序方式: 共有973条查询结果,搜索用时 15 毫秒
891.
Algirdas Augustaitis Ingrida Augustaitienė Almantas Kliučius Gintaras Pivoras Dalia Šopauskienė Raselė Girgždienė 《European Journal of Forest Research》2010,129(3):431-441
The multiple-stressor effects of air pollution, nutrient and water availability are the key issues of present forest ecosystem
research. However, too little is known about the seasonal effect of pollutants on tree crown defoliation and their interaction
with changes in climate. Therefore, data on seasonal variation in air pollution, including surface ozone, deposition of acidifying
compounds and meteorological conditions, were tested against pine defoliation to identify the periods when the effect of the
considered contaminants is most pronounced. The findings of the study revealed that a higher level of air concentrations of
acidifying pollutants and their deposition was observed during the dormant period, with the exception of only ΣNH4+ air concentrations and their monthly deposition. An increase in precipitation over the vegetation period and mean monthly
temperature from September to December, as well as a decrease in temperature and precipitation over the remaining months of
the dormant period represented the climate change condition over the 14-year period in the observed region. Detected changes
in the considered parameters during the dormant period were found to be most significant to changes in pine crown defoliation.
Therefore, we concluded that climate changes, if they occur by the detected scenarios, should mitigate the negative effect
of air pollutants and acid deposition on pine crown condition. 相似文献
892.
Sara Bensadón Deisy Hervert-Hernández Sonia G. Sáyago-Ayerdi Isabel Goñi 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(3):210-216
Dietary fiber and bioactive compounds are widely used as functional ingredients in processed foods. The market in this field
is competitive and the development of new types of quality ingredients for the food industry is on the rise. Opuntia ficus-indica (cactus pear) produces edible tender stems (cladodes) and fruits with a high nutritional value in terms of minerals, protein,
dietary fiber and phytochemicals; however, around 20% of fresh weight of cladodes and 45% of fresh weight of fruits are by-products.
The objective of this study was therefore to determine the nutritional value of by-products obtained from cladodes and fruits
from two varieties of Opuntia ficus-indica, examining their dietary fiber and natural antioxidant compound contents in order to obtain quality ingredients for functional
foods and increase the added value of these by-products. 相似文献
893.
Ladislav Cséfalvay Gabriele Di Gaspero Karel Matouš Diana Bellin Benedetto Ruperti Julie Olejníčková 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(2):291-302
Plasmopara viticola is an economically important pathogen of grapevine. Early detection of P. viticola infection can lead to improved fungicide treatment. Our study aimed to determine whether chlorophyll fluorescence (Chl-F)
imaging can be used to reveal early stages of P. viticola infection under conditions similar to those occurring in commercial vineyards. Maximum (FV/FM) and effective quantum yield of photosystem II (ΦPSII) were identified as the most sensitive reporters of the infection. Heterogeneous distribution of FV/FM and ΦPSII in artificially inoculated leaves was associated with the presence of the developing mycelium 3 days before the occurrence
of visible symptoms and 5 days before the release of spores. Significant changes of FV/FM and ΦPSII were spatially coincident with localised spots of inoculation across the leaf lamina. Reduction of FV/FM was restricted to the leaf area that later yielded sporulation, while the area with significantly lower ΦPSII was larger and probably reflected the leaf parts in which photosynthesis was impaired. Our results indicate that Chl-F can
be used for the early detection of P. viticola infection. Because P. viticola does not expand systemically in the host tissues and the effects of infection are localised, Chl-F imaging at high resolution
is necessary to reveal the disease in the field. 相似文献
894.
Irena Mavrič Pleško Mojca Viršček Marn Saša Širca Gregor Urek 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(3):261-268
In 2003, Raspberry bushy dwarf virus was found for the first time in grapevine. Since this was the first report of a non-Rubus natural host, information about it is sparse. During this study the grapevine isolates were characterised biologically, serologically
and genetically and compared with known information about Rubus isolates. Infected plant material was used for mechanical inoculation of test plants, and for serological characterisation
with monoclonal antibodies. Most of RNA 2 was sequenced and compared with other sequences from the database. Grapevine isolates
infected Chenopodium murale systemically, which is not known for raspberry isolates. They were differentiated from Slovenian raspberry isolates with
three monoclonal antibodies using TAS-ELISA. Phylogenetic analyses clustered grapevine isolates separately from raspberry
isolates. Additionally, the virus was detected using nested RT-PCR in Longidorus juvenilis nematodes collected in an infected vineyard. Grapevine isolates of RBDV are distinct from raspberry isolates. 相似文献
895.
Vesna Ilić Zoran Šaponjić Vesna Vodnik Darka Mihailović Petar Jovančić Jovan Nedeljković Maja Radetić 《Fibers and Polymers》2009,10(5):650-656
The aim of this study was to examine the influence of dyeing on antibacterial efficiency of corona activated polyamide and polyester fabrics loaded with colloidal Ag nanoparticles as well as the influence of the presence of Ag nanoparticles on the color change of dyed fabrics. C.I. Acid Green 25 and C.I. Disperse Blue 3 were used for dyeing of polyamide fabrics and C.I. disperse violet 8 for polyester fabrics. The color change of polyamide fabrics depends on the dye type, which was generally lower compared to polyester fabrics. Antibacterial efficiency of Ag loaded fabrics was tested against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli. Corona activated polyester and polyamide fabrics showed excellent antibacterial efficiency independently of order of dyeing and Ag loading. The morphology of fibers loaded with Ag nanoparticles was assessed by SEM and atomic absorption spectroscopy for elemental analysis. 相似文献
896.
The toxicity of six pesticides (four insecticides and two fungicides) to Orius majusculus (Reuter) (Hemiptera: Anthocoridae) adults and nymphs was determined using different exposure methods. Mortality upon topical
exposure to abamectin, endosulfan and spinosad at recommended field doses ranged from 56% to 100% after 24 h. However, in
leaf residue tests, toxicity to both life stages decreased significantly, ranging from 0% to 33% mortality. Benomyl and copper
salts + mancozeb (fungicides) were much less toxic to O. majusculus, with less than 15% mortality of either adults or nymphs in topical and residue bioassays. In persistent toxicity tests,
insects were exposed to the same three insecticides for 4 days; mortality varied from 38% to 100%. Egg hatching was not significantly
affected when abamectin, endosulfan and spinosad were topically applied. Number of eggs laid per female in choice and no-choice
tests did not differ significantly from the control. The insecticides did not show considerable repellent effect in the choice
tests. Topical, residue and systemic uptake methods were also compared to determine the differences in the toxicity levels
of imidacloprid, a systemic insecticide. However, 100% mortality occurred with all methods. 相似文献
897.
Faganeli J Mohar B Kofol R Pavlica V Marinšek T Rozman A Kovač N Vuk AŠ 《Marine drugs》2010,8(9):2480-2492
The key organic constituents of marine macroaggregates (macrogels) of prevalently phytoplankton origin, periodically occurring in the northern Adriatic Sea, are proteins, lipids and especially polysaccharides. In this article, the reactivity of various macroaggregate fractions in relation to their composition in order to decode the potentially »bioavailable« fractions is summarized and discussed. The enzymatic hydrolysis of the macroaggregate matrix, using α-amylase, β-glucosidase, protease, proteinase and lipase, revealed the simultaneous degradation of polysaccharides and proteins, while lipids seem largely preserved. In the fresh surface macroaggregate samples, a pronounced degradation of the α-glycosidic bond compared to β-linkages. Degradation of the colloidal fraction proceeded faster in the higher molecular weight (MW) fractions. N-containing polysaccharides can be important constituents of the higher MW fraction while the lower MW constituents can mostly be composed of poly- and oligosaccharides. Since the polysaccharide component in the higher MW fraction is more degradable compared to N-containing polysaccharides, the higher MW fraction represents a possible path of organic nitrogen preservation. Enzymatic hydrolysis, using α-amylase and β-glucosidase, revealed the presence of α- and β-glycosidic linkages in all fractions with similar decomposition kinetics. Our results indicate that different fractions of macroaggregates are subjected to compositional selective reactivity with important implications for macroaggregate persistence in the seawater column and deposition. 相似文献
898.
Aleš Mráček Marián Lehocký Petr Smolka Ondřej Grulich Vladimír Velebný 《Fibers and Polymers》2010,11(8):1106-1110
This article describes the novel possibility of the polyester (polyethylene terephthalate) surface modification by plasma
treatment. Moreover, this modified polyester could be component for the composite material (with hyaluronic acid) used in
the wound healing. In this study, the experimental methods: FT-IR spectroscopy, the contact angle measurement, X-ray photoelectron
spectroscopy and scanning electron microscopy were used for the surface modified polyester characterisation. 相似文献
899.
Martina Šturm Nina Kacjan-Maršić Vesna Zupanc Branka Bračič-Železnik Sonja Lojen Marina Pintar 《Scientia Horticulturae》2010
The effect of different fertilisation (i.e. broadcast application and fertigation) and irrigation practices (tank sprinkler and drip irrigation) on yield, yield quality (nitrate content), nitrogen uptake of white cabbage (Brassica oleracea var. capitata L.) and the potential for N losses was assessed on sandy-loam agricultural soil. 15N-labelled fertiliser was used as a tracer. It was found that different practices significantly affected yield, nitrate content in plants, N uptake, as well as fertiliser use efficiency. The highest yield (93 t ha−1), plant N uptake (246 kg ha−1), and fertiliser use efficiency (42%) were obtained under treatment with broadcast fertilisation with farmer's practice of irrigation (tank sprinkler). The N surplus after harvest was −41 kg N ha−1, indicating the lowest potential for N losses. Treatment by fertigation and drip irrigation covering 100% of the crop's water requirements did not result in the highest yield as expected (72 t ha−1), the N surplus after harvest was about +38 kg ha−1. The lowest yield (58 t ha−1), fertiliser use efficiency (30%) and hence the highest potential for N losses (N surplus after harvest +68 kg ha−1) were found in treatment with broadcast fertilisation and drip irrigation covering 50% of the crop's water requirements. 相似文献
900.
Àngel Fernández i Martí Toshio Hanada José M. Alonso Hisayo Yamane Ryutaro Tao Rafel Socias i Company 《Scientia Horticulturae》2010
Since self-compatibility has become the primary objective of most almond breeding programmes, search for new self-compatibility sources has acquired a great importance in almond research. The local Spanish cultivar ‘Vivot’, identified as showing the genotype S23Sf, thus presumably self-compatible, was found to be unexpectedly self-incompatible in spite of the presence of the Sf allele, as also observed in other almond cultivars. However, not only the coding sequences of both the Sf-RNase and the SFBf of ‘Vivot’ and ‘Blanquerna’, a confirmed self-compatible cultivar, were identical, but also the 5′ regulatory sequence of the Sf-RNase of both. Thus, the reason for the different expression of the Sf is independent of the complete genetic identity found in the whole chromosome region bordering the S-locus in the almond cultivars sharing the Sf allele. 相似文献