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BACKGROUND: The herbicide atrazine was intercalated in the interlayer region of Mg/Al layered double hydroxides in order to produce a nanohybrid that could be used in controlled‐release applications. RESULTS: The hydrophobic herbicide was incorporated in artificial membranes formed in the interlayer of the inorganic host by using palmitic acid. The synthetic nanohybrid material was characterised by various techniques, and release studies were carried out. In addition, the photosynthetic alga Chlamydomonas reinhardtii Dang. was treated with the atrazine‐containing nanohybrid, which exerted an herbicidal efficacy similar to that of the free herbicide. CONCLUSION: The herbicide containing nanohybrid could enable a controlled release of the herbicide. In addition, the herbicide would be delivered close to its site of uptake, enhancing efficiency and reducing the required doses. Copyright © 2011 Society of Chemical Industry 相似文献
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Effrosyni D. Karanika Olga K. Voulgari Andreas P. Mamolos Demetrios A. Alifragis Demetrios S. Veresoglou 《Pedobiologia》2008,51(5-6):409-418
Abundance of arbuscular mycorrhizal fungi (AMF) in the roots of plant species was assessed in two areas in Greece in a 4-year study (2004–2007). The field experiment was conducted in a mountainous and herbaceous grassland in Greece in which both nitrogen (N)- and phosphorus (P)-limited plant community productivity. In 2006, data were also collected from a pot experiment in which 14 herbaceous plant species were grown as monocultures in P-limited soil. A factorial design of two levels of N and P was established in the mountainous field to test plant response to nutrient additions with respect to AMF colonization levels. Effects of fungicides were also investigated over year in the pot experiment and over three years in the field experiment. In addition, the effect of irrigation on AMF colonization was determined in a 1-year field study. Measurements included estimating the level of plant species specific hyphal colonization of roots according to the McGonicle et al. [McGonigle, T.P., Miller, M.H., Evans, D.G., Fairchild, D.L., Swan, J.A., 1990. A new method which gives an objective measure of colonization of roots by vesicular–arbuscular mycorrhizal fungi. New Phytol. 115, 495–501] method. AMF colonization was highest in the leguminous species, intermediate in the forbs and lowest in the grasses. AMF responses to N and P additions were not uniform. P addition in the field experiment increased the colonization level of the high P demanding annual forb (non-leguminous dicot) Galium lucidum, decreased hyphal abundance of the forb Plantago lanceolata and the grass Agrostis capillaris, and appeared to have a negligible effect on the forb Prunella vulgaris and on leguminous species. Effects of N addition were influenced by P addition and were only significant in plots not enriched with P where N addition increased the AMF colonization. Irrigation increased colonization of the tested species A. capillaris and P. lanceolata but only significantly increased that of P. lanceolata. There was interannual variation in the effects of fungicides on AMF colonization, which was partly due to differences in the active ingredient and formulation used. Among the tested species, A. capillaris was the most susceptible to fungicides. 相似文献
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Demetrios G. Hadjidemetriou Yutaka Iwata Francis A. Gunther 《Pest management science》1985,16(3):302-310
Dislodgable residues of acephate and its hydrolysis product methamidophos, dimethoate and its oxygen analogue omethoate (dimethoxon), and formetanate hydrochloride on citrus foliage were determined by gas–liquid chromatography. The use of 5% OV-101 coated on a Carbowax 20M surface-modified support (Ultra-Bond 20M) allowed the reproducible analysis of dimethoate and omethoate residues. Formetanate hydrochloride residues were analysed as the free base, without preparation of a derivative, on a column packed with 5% Apiezon N coated on 80–100 mesh Ultra-Bond 20M. The dissipation of the residues of the three pesticides applied to citrus trees was studied. Acephate and formetanate hydrochloride dissipation curves followed first-order kinetics; dimethoate residues were best characterised by two first-order kinetic processes. The half-life values were 8.2 days for acephate, undeterminably long for formetanate hydrochloride, and 2.2 days (the 1–10 days portion) and 7.0 days (the 10–49 days portion) for dimethoate. 相似文献
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Stagos D Spanou C Margariti M Stathopoulos C Mamuris Z Kazantzoglou G Magiatis P Kouretas D 《Journal of agricultural and food chemistry》2007,55(13):5246-5252
In the present study, the effects of extracts and polyphenol-rich fractions as well as monomer polyphenols identified in them, from both red and white grapes, on mitomycin C (MMC) induced sister chromatid exchanges (SCEs) in human peripheral blood lymphocytes were investigated. The grape extracts and two of the three polyphenol-rich fractions promoted MMC-induced SCEs at concentrations from 75 to 300 microg/mL. However, none of the extracts or fractions alone induced SCEs. Thus, these results suggest caution especially with regard to the use of grape extracts as dietary supplements. On the other hand, the fact that these extracts were not genotoxic alone may indicate a selective activity against genetically damaged cells. This is the first study regarding the clastogenic effects of grape extracts in human cells. Moreover, from the tested polyphenols, caffeic acid, gallic acid, and rutin hydrate enhanced MMC-induced clastogenicity, whereas ferulic acid, protocatechuic acid, (+)-catechin, (-)-epicatechin, and trans-resveratrol had no effect at concentrations between 5 and 100 microM. The differences in the chemical structures of the tested polyphenols may account for their differential effects on MMC clastogenicity. 相似文献
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Spanou C Bourou G Dervishi A Aligiannis N Angelis A Komiotis D Skaltsounis AL Kouretas D 《Journal of agricultural and food chemistry》2008,56(16):6967-6976
Recently, phytochemical compounds present in legumes have gained a lot of interest because they are considered to be possible chemopreventive agents. In the present study, 14 polyphenolic compounds were extracted and identified from two unique varieties of Leguminosae family plants cultivated in Greece and screened for their antioxidant and chemopreventive properties. Ten polyphenolic fractions, which are mainly mixtures of two compounds and five pure flavonoids, were isolated from the methanolic extracts of aerial plant parts of Vicia faba and Lotus edulis (Leguminosae), respectively. All of these fractions exhibited significant DPPH(*) radical scavenging capacity. Furthermore, they exerted significant protective activity against free radical-induced DNA damage. This activity was more potent against ROO(*) radical-induced DNA damage than against that induced by OH(*) radicals. Finally, they exhibited significant ability to inhibit the activity of the topoisomerase I enzyme. These results imply that the polyphenolic compounds identified in the fractions were responsible of the observed properties of the fractions and the initial extracts and indicate different mechanisms by which these phenolic compounds may act as chemopreventive agents. 相似文献
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The effectiveness of a cultivar evaluation scheme is impeded by the cost of experimentation. The aim of this study was to explore whether the locations employed in durum wheat evaluation program in Greece constituted a mega-environment (ME) and to adjust the number of trial replications and locations for realizing an optimum heritability (H) of 0.75. The analysis was conducted for grain yield (GY), agronomic and quality parameters in a 10-year (2002–2011) dataset and included a variable across years, number of genotypes and locations. The GGE biplot analyses revealed that trial locations can be considered as a single, complex ME. The existence of the ME was also confirmed by the high H across locations. The number of replications and locations for realizing an optimum H for GY was five replications compared to the four currently used, and five locations in lieu of 3–4 now tested. Plant height in March, final plant height and days to heading required three replications and four locations, winter frost three and five, powdery mildew three and seven, stem rust five and nine, whereas lodging 10 replications and 10 locations, respectively. Regarding quality, thousand-kernel weight required four replications and three locations, whereas vitreous kernel percentage six and eight, grain protein concentration four and seven, black point percentage 17 replications and was of zero H across locations. Finally, for the traits assessed only across locations, ash content required seven, wet gluten content five while gluten index and β-carotene three locations. 相似文献
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Harold S. J. Zald Thomas A. Spies Manuela Huso Demetrios Gatziolis 《Landscape Ecology》2012,27(8):1197-1212
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced tree invasion. We combined airborne Light Detection and Ranging (LiDAR) characterizations of landforms, topography, and overstory vegetation with historical climate, field measurements of snow depth, tree abundance, and tree ages to reconstruct spatial and temporal patterns of tree invasion over five decades in a subalpine meadow complex in the Oregon Cascade Range, USA. Proportion of meadow occupied by trees increased from 8?% in 1950 to 35?% in 2007. Larger landforms, topography, and tree canopies interactively mediated regional climatic controls of tree invasion by modifying depth and persistence of snow pack, while tree canopies also influenced seed source availability. Landscape context played an important role mediating snow depth and tree invasion; on glacial landforms tree invasion was negatively associated with spring snowfall, but on debris flows tree invasion was not associated with snow fall. The importance of snow, uncertain climate change impacts on snow, and mediation of snow by interacting and context dependent factors in complex mountain terrain poses substantial hurdles for understanding how these ecotones may respond to future climate conditions. 相似文献
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Demetrios John Vakalounakis 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(9):855-858
The inheritance of resistance toFusarium oxysporum f.sp.cucumerinum race 1 was determined in the cucumber cv. WIS-248 by analyzing segregation of F1, F2, and BC populations of crosses with the susceptible cv. Straight-8. Resistance was conferred by a single dominant gene. In an allelism test, it was proven that theFcu-1 gene, which confers resistance toF. oxysporum f.sp.cucumerinum races 1 and 2 in cucumber cv. SMR-18 and theFoc gene, which confers resistance toF. oxysporum f.sp.cucumerinum race 2 in cucumber cv. WIS-248, are indistinguishable. 相似文献
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Androniki Bolla Demetrios Voyiatzis Magdalene Koukourikou-Petridou Dora Chimonidou 《Scientia Horticulturae》2010
The aim of the present study was to provide a better insight into the adaptive processes within rose plants ‘Eurored’ (Hybid Tea), grown in soilless cultivation, when exposed to water deficit. Rose plants were grown in three different substrates (perlite, pine bark–almond shells 1:1, and perlite–pumice 1:1) and under two water regimes (100 and 67% of the irrigation needs). Photosynthetic parameters, water relations, leaf chlorophyll content, chlorophyll fluorescence and cut-flower production were determined. 相似文献
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Ioannis A. Papaioannou Eleftherios K. Ligoxigakis Demetrios J. Vakalounakis Emmanouil A. Markakis Milton A. Typas 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(3):577-596
A population of 84?V. dahliae isolates mainly originating from Crete, Greece, was characterized in terms of pathogenicity and virulence on different hosts, in parallel with morphological/physiological characterization, vegetative compatibility grouping and mating type determination. Tomato race 2 was found to have supplanted race 1 and was more virulent on a tomato-susceptible cultivar than race 1. Using a differential host classification system which tests pathogenicity to tomato, eggplant, sweet pepper and turnip, 59 isolates were assigned to tomato, 19 to eggplant, one to sweet pepper and five to tomato-sweet pepper pathogenicity groups. All isolates from Crete fell into VCG subgroups 2A, 2B and 4B, while a remarkably high incidence of bridging isolates (compatible with two or more VCGs) was recorded. The tomato-sweet pepper pathogenicity group was morphologically quite distinct from the others, while conidial length and pigment intensity were discriminatory parameters among VCGs 2A, 2B and 4B. PCR-based molecular marker Tr1/Tr2 was reliable in race prediction among tomato-pathogenic isolates, except for members of VCG 4B, while the application of markers Tm5/Tm7 and 35-1/35-2 was highly successful for tomato-pathogenic isolates. E10 marker was related to VCG 2B, rather than to pathogenicity groups. A single nucleotide polymorphism in the ITS2 region, and two novel molecular markers, M1 and M2, proved useful for the fast and accurate determination of major VCGs 2A, 2B and 4B, and can be used for high-throughput population analyses in future studies. The mating type was unrelated to VCG classification and probably does not control heterokaryon incompatibility in V. dahliae. 相似文献
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