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1.
Marie-France Corio-Costet Muriel Dall'Agnese Ren Scalla 《Pesticide biochemistry and physiology》1991,40(3)
A soybean cell line tolerant to isoxaben was isolated by callus selection in herbicide-containing medium. The growth of tolerant suspension cells was not affected by 10 μM isoxaben, which prevented the growth of wild-type cultures. The growth of a wheat cell culture was little affected by isoxaben, in accordance to the tolerance of wheat plants to the herbicide. The metabolic fate of labeled isoxaben in the three types of cultures was examined. By comparison with the sensitive, wild-type soybean cell culture, the tolerance of the selected soybean cell culture and that of wheat cell culture cannot be explained by either quantitative or qualitative differences of herbicide metabolism. These results favor the hypothesis that the sensitivity or tolerance of the cell cultures is determined at the level of the cellular target of the herbicide. 相似文献
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Haddad M Herent MF Tilquin B Quetin-Leclercq J 《Journal of agricultural and food chemistry》2007,55(15):6082-6086
The microbiological contamination of raw plant materials is common and may be adequately reduced by radiation processing. This study evaluated the effects of gamma- and e-beam ionizing radiations (25 kGy) on three plants used as food or as medicinal products (Thymus vulgaris L., Eucalyptus radiata D.C., and Lavandula angustifolia Mill.) as well as their effects on extracted or commercial essential oils and pure standard samples. Comparison between irradiated and nonirradiated samples was performed by GC/FID and GC/MS. At the studied doses, gamma and e-beam ionizing radiation did not induce any detectable qualitative or quantitative significant changes in the contents and yields of essential oils immediately after ionizing radiation of plants or commercial essential oils and standards. As the maximum dose tested (25 kGy) is a sterilizing dose (much higher than doses used for decontamination of vegetable drugs), it is likely that even decontamination with lower doses will not modify yields or composition of essential oils of these three plants. 相似文献
4.
Majdi Mansouri Benjamin Dumont Vincent Leemans Marie-France Destain 《Precision Agriculture》2014,15(2):184-201
LAI of winter wheat (Triticum aestivum L.) and soil water content of the topsoil (200 mm) and of the subsoil (500 mm) were considered as state variables of a dynamic soil-crop system. This system was assumed to progress according to a Bayesian probabilistic state space model, in which real values of LAI and soil water content were daily introduced in order to correct the model trajectory and reach better future evolution. The chosen crop model was mini STICS which can reduce the computing and execution times while ensuring the robustness of data processing and estimation. To predict simultaneously state variables and model parameters in this non-linear environment, three techniques were used: extended Kalman filtering (EKF), particle filtering (PF), and variational filtering (VF). The significantly improved performance of the VF method when compared to EKF and PF is demonstrated. The variational filter has a low computational complexity and the convergence speed of states and parameters estimation can be adjusted independently. Detailed case studies demonstrated that the root mean square error of the three estimated states (LAI and soil water content of two soil layers) was smaller and that the convergence of all considered parameters was ensured when using VF. Assimilating measurements in a crop model allows accurate prediction of LAI and soil water content at a local scale. As these biophysical properties are key parameters in the crop-plant system characterization, the system has the potential to be used in precision farming to aid farmers and decision makers in developing strategies for site-specific management of inputs, such as fertilizers and water irrigation. 相似文献
5.
Meadows are often managed by mowing to prevent succession and brushwood encroachment. This management practice is efficient to maintain plant diversity, but the effect on arthropod groups is less well known. We sampled spiders in the Grande Cariçaie (Switzerland), a site of nature conservation importance, in two types of wet meadows, an unmanaged site and one 2-years-old mown conditions. Numbers of individuals for the most abundant families, diversity measures, and indicator taxa were compared among vegetation and treatment types. The results indicate that the less mobile spiders and species linked to litter or dead reeds, including rare species, are reduced by mowing. Present management consists in triennial mowing of 2-4 ha non-contiguous sectors. We investigate the conflict between the need to mow the meadows to maintain them, and the negative effect of mowing on spider communities. We therefore propose a new management scheme aimed at maintain the vegetation while lessening its negative effects on spider communities by providing refuges. 相似文献
6.
Marie-France Corio-Costet Marie-Cécile Dufour Jérémy Cigna Pierre Abadie Wei-Jen Chen 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(2):315-329
The effectiveness of Quinone outside Inhibitor (QoI) fungicides against grape downy mildew in European vineyards has significantly
decreased in the last decade. One nucleotide polymorphism, G143A in the cytochrome b gene of Plasmopara viticola, is involved in resistance to QoIs. Previous genetic examination on the mitochondrial genomes showed four major haplotypes
(IR, IS, IIR, IIS) coexisting in European vineyards. A resistant allele (G143A) was present in IR and IIR haplotypes. The
purpose of the present study was to estimate the diversity of the different mitochondrial haplotypes and their distribution
in QoI-resistant populations before evaluating the potential cost of the resistant mutation G143A in P. viticola population. From 2000 to 2004, the frequencies of resistant isolates ranged from 0% to 23.25% with an average of 4.64 % among
the populations examined. To evaluate the fitness of sensitive and resistant isolates, a comparison of different biological
parameters including latent period, spore production and infection frequency was performed, enabling a fitness index (FI) to be determined. Resistant isolates exhibited greater infection frequency than sensitive isolates, whereas no significant
difference was found in sporulation ability and latent period between sensitive and resistant isolates. To further investigate
competitiveness among isolates, an assay including two resistant isolates in different proportion with a sensitive isolate
was conducted on eight asexual growing cycles in the absence of a QoI fungicide. The competitiveness of resistant isolates
varied according to their fitness parameters, suggesting that there is no noticeable cost of QoI resistance in controlled
conditions in Plasmopara viticola. 相似文献
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Wheatley Brian Paradis Sylvain Lassonde Maryse Giguere Marie-France Tanguay Serge 《Water, air, and soil pollution》1997,97(1-2):63-73
Health Canada has been collecting data on Inuit and First Nations' methylmercury (MeHg) levels for 25 years. A national overview has been completed and more focussed analyses have now been initiated. This paper deals with two interdependent analytical components: 1) a longitudinal overview of the two most extensively sampled communities in Canada: Grassy Narrows and Whitedog, the residents of which were exposed to ‘point source’ mercury pollution in the 1970's; 2) fetal and post-natal exposure to mercury in these two communities including an outline of the First Nation MeHg child development pilot project in the two communities. A retrospective analysis of Grassy Narrows and Whitedog shows a decreasing MeHg trend in both communities. In Grassy Narrows the average individual annual peak methylmercury level in blood has decreased significantly, from 23.80 ppb (range 1.50–322.90) in 1976 to 7.5 ppb (1.7–46.7) in 1995 (r=-0.65, p<0.001). In Whitedog the average peak has also decreased significantly, from 12.87 ppb (1.50–172.00) in 1976 to 6.1 ppb (1.7–33.3) in 1995 (r=-0.59, p<0.005). However, behind these positive trends is the reality of two communities still suffering the effects of disrupted lifestyles and socio-cultural damage. A number of cord blood samples, maternal blood samples, and samples from women of child-bearing age from these communities have been in the “risk” group (according to the 1990 WHO guidelines). We are therefore now assessing the long term effects of fetal exposure in the communities. Standard clinical examinations in the past failed to prove abnormalities attributable to methylmercury but did not include subtle neuropsychological development tests. Many of the fetally exposed children are now in secondary school. Therefore, we have initiated a pilot project to assess long term effects of methylmercury exposure on the neuropsychological development of these children whose fetal exposure we know. The pilot child development project which was initiated in 1995 in Grassy Narrows and Whitedog, with community support, includes four main components: i) a school records review, looking at attendance, marks, and atypical behaviour; ii) teachers' questionnaires, targeting child behaviour; iii) an in-depth neuropsychological test battery focussing on subtle factors, such as memory, attention, executive functions, perceptual functions and sensory / motor development; and iv) hair sampling, providing current MeHg levels to correlate with results from the previous sampling and findings from the first three components. An overview of progress is given. 相似文献
8.
Effects of garlic powders with varying alliin contents on hepatic drug metabolizing enzymes in rats 总被引：3，自引：0，他引：3
Le Bon AM Vernevaut MF Guenot L Kahane R Auger J Arnault I Haffner T Siess MH 《Journal of agricultural and food chemistry》2003,51(26):7617-7623
The anticarcinogenic effect of garlic has been demonstrated in both epidemiologic and experimental studies. In this study, possible mechanisms involved in the anticarcinogenic effect of garlic consumption were assessed by determining its capacity to alter drug metabolizing enzymes, in relation with its alliin content. Rats were fed a diet for 2 weeks containing 5% garlic powders produced from bulbs grown on soils with different levels of sulfate fertilization and therefore containing differing amounts of alliin. Activities of several hepatic enzymes, which are important in carcinogen metabolism such cytochromes P450 (CYP) and phase II enzymes, were determined. Garlic consumption slightly increased ethoxyresorufin O-deethylase and CYP 1A2 levels. In contrast, garlic consumption decreased CYP 2E1 activity and the level of the corresponding isoform. UDP glucuronosyl transferase and glutathion S-transferase activities were increased by garlic powders. The alliin content of the garlic powders was positively correlated with UGT activity although not with other activities. Effects produced by garlic consumption were qualitatively similar to that of diallyl disulfide, a sulfur compound that has been extensively studied. These data could partially explain the chemoprotective effect of garlic. 相似文献
9.
Christophe Dlye Frdric Laigret Marie-France Corio-Costet 《Pest management science》1997,51(3):309-314
Using a Random Amplified Polymorphic DNA (RAPD) assay, we investigated the genetic polymorphism existing among 62 European isolates of the grape powdery mildew fungus (Uncinula necator [Schw.] Burr.). Isolates overwintering as mycelium in buds were genetically distinct from isolates overwintering as ascospores, suggesting the existence of two genetically isolated powdery mildew populations, and consequently of two independent sources of inoculum in the vineyard. Isolates resistant to fungicides inhibiting sterol 14α-demethylation (DMIs) were found in both populations, suggesting that resistance to DMIs may arise independently in the two powdery mildew populations. A PCR assay targeting the gene encoding U. necator 14α-demethylase has been developed which will permit an early, specific detection of U. necator infections, and may be useful for spraying programmes. ©1997 SCI 相似文献
10.
Aida Se Golpayegani Iris Brémaud Joseph Gril Marie-France Thevenon Olivier Arnould Kambiz Pourtahmasi 《Journal of Wood Science》2012,58(2):153-162
Vibrational properties of wood are affected by several parameters, of which extractives can be one of the most important ones.
Wood for European musical instruments has been often studied, but traditional Middle Eastern ones had been left unnoticed.
In this study white mulberry (Morus alba L.), the main material for long-necked lutes in Iran, was extracted by five solvents of various polarities (water included).
Free-free bar forced vibrations were used to measure longitudinal (L) loss tangent (tanδ), storage (elastic) modulus (E′) and specific modulus (E′/γ) in the acoustic range. Their anisotropy between the 3 axes of orthotropy was determined by dynamic mechanical analysis.
Native wood had a quite low E
L′/γ but its tanδ was smaller than expected, and the anisotropy of tanδ and E′/γ was very low. Removal of extractives caused tanδ to increase and moduli to decrease. Acetone, the most effective solvent on damping despite a moderate extraction yield, increased
tanδ
L by at least 20% but did not modify E′/γ as much. When used successively, its effects masked those of solvents used afterwards. Anisotropy of E′/γ was nearly unchanged after extraction in methanol or hot water, while tanδ was much more increased in R than in T direction. Results suggest that in white mulberry, damping is governed more by nature
and localization of extractives rather than by their crud abundance. 相似文献