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排序方式: 共有364条查询结果,搜索用时 15 毫秒
1.
2.
Resistance to Botrytis cinerea in Solanum lycopersicoides is Dominant in Hybrids with Tomato, and Involves induced Hyphal Death 总被引:2,自引:0,他引:2
Rejane L. Guimarães Roger T. Chetelat Henrik U. Stotz 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(1):13-23
Botrytis cinerea causes gray mold disease and affects hundreds of plant species, including tomato (Lycopersicon esculentum). The wild nightshade, Solanum lycopersicoides, is cross compatible with tomato and is more resistant to B. cinerea, thus representing a potential source for crop improvement. Tests involving droplet inoculation of detached leaves and spray inoculation of entire seedlings demonstrated that resistance to B. cinerea varies among S. lycopersicoides accessions, with S. lycopersicoides LA2951 being the most resistant accession tested. Expression of resistance in the intergeneric hybrid (L. esculentum cv. 'VF36' × S. lycopersicoides LA2951) suggested that resistance is at least partially dominant in tomato. A green fluorescent protein-tagged B. cinerea strain was used for confocal microscopic comparison of infection in leaves of S. lycopersicoides and tomato. Even though S. lycopersicoides supported spore germination, there was evidence for hyphal lysis and death 3 days after inoculation, at a time when lesions were expanding on susceptible tomato plants. The reduced frequency of B. cinerea lesion spread on S. lycopersicoides explains why this fungus produced fewer spores in this wild nightshade than in tomato. 相似文献
3.
Amir Atabak Ronaghinia Nanett Kvist Nikolaisen Stine Green Hansen Helle Harding Poulsen Henrik Lauritz Frandsen Tina Struve Pierre‐Louis Toutain Peter Damborg 《Journal of veterinary pharmacology and therapeutics》2021,44(1):93-106
Antimicrobial agents are used extensively off‐label in mink, as almost no agents are registered for this animal species. Pharmacokinetic (PK) and pharmacodynamic (PD) data are required to determine antimicrobial dosages specifically targeting mink bacterial pathogens. The aims of this study were to assess, in a PKPD framework, the empirical dosage regimen for a combination of trimethoprim (TMP) and sulfadiazine (SDZ) in mink, and secondarily to produce data for future setting of clinical breakpoints. TMP and SDZ PK parameters were obtained experimentally in 22 minks following IV or oral administration of TMP/SDZ (30 mg/kg, i.e. 5 mg/kg TMP and 25 mg/kg SDZ). fAUC/MIC with a target value of 24 hr was selected as the PKPD index predictive of TMP/SDZ efficacy. Using a modeling approach, PKPD cutoffs for TMP and SDZ were determined as 0.062 and 16 mg/L, respectively. By incorporating an anticipated potentiation effect of SDZ on TMP against Escherichia coli and Staphylococcus delphini, the PKPD cutoff of TMP was revised to 0.312 mg/L, which is above the tentative epidemiological cutoffs (TECOFF) for these species. The current empirical TMP/SDZ dosage regimen (30 mg/kg, PO, once daily) therefore appears adequate for treatment of wild‐type E. coli and S. delphini infections in mink. 相似文献
4.
Growth and carbon dynamics in mixed grass–red clover leys were simulated using a growth model for pure stands based on radiation use, allocation within plant and loss of biomass. The model and its parameter values were taken from previous applications of the model to pure swards of grass and red clover grown in the same experiment at the same sites and years. 相似文献
5.
Metsulfuron methyl sorption-desorption in field-moist soils 总被引:4,自引:0,他引:4
Berglöf T Koskinen WC Duffy MJ Norberg KA Kylin H 《Journal of agricultural and food chemistry》2003,51(12):3598-3603
Pesticide sorption coefficients (K(d)) are generally obtained using batch slurry methods. As a consequence, the results may not adequately reflect sorption processes in field-moist or unsaturated soil. The objective of this study was to determine sorption of metsulfuron methyl, a weak acid, in field-moist soils. Experiments were performed using low density (i.e., 0.3 g mL(-)(1)) supercritical fluid carbon dioxide (SF-CO(2)) to convert anionic metsulfuron methyl to the molecular species and remove it from the soil water phase only, thus allowing calculation of sorption coefficients (K(d)) at low water contents. K(d) values for sorption of the metsulfuron methyl molecular species on sandy loam, silt loam, and clay loam soil at 11% water content were 120, 180, and 320 mL g(-)(1), respectively. Using neutral species K(d) values, the pK(a) of metsulfuron methyl, and the pH of the soil, we could successfully predict the K(d) values obtained using the batch slurry technique, which typically has a predominance of anionic species in solution during the sorption characterization. This application of supercritical fluid extraction to determine sorption coefficients, combined with sulfonylureas' pK(a) values and the soil pH, will provide an easy method to predict sorption in soil at different pH levels. 相似文献
6.
Josefine Nymark Hegelund Uffe Bjerre Lauridsen Sabá Victoria Wallström Renate Müller Henrik Lütken 《Euphytica》2017,213(2):51
Compact growth is an important quality criterion in horticulture. Many Campanula species and cultivars exhibit elongated growth which is suppressed by chemical retardation and cultural practice during production to accommodate to the consumer’s desire. The production of compact plants via transformation with wild type Agrobacterium rhizogenes is an approach with great potential to produce plants that are non-GMO. Efficient transformation and regeneration procedures vary widely among both plant genera and species. Here we present a transformation protocol for Campanula. Hairy roots were produced on 26–90% of the petioles that were used for transformation of C. portenschlagiana (Cp), a C. takesimana × C. punctata hybrid (Chybr) and C. glomerata (Cg). Isolated hairy roots grew autonomously and vigorously without added hormones. The Cg hairy roots produced chlorophyll and generated plantlets in response to treatments with cytokinin (42 µM 2iP) and auxin (0.67 µM NAA). In contrast, regeneration attempts of transformed Cp and Chybr roots lead neither to the production of chlorophyll nor to the regeneration of shoots. Agropine A. rhizogenes strains integrate split T-DNA in TL- and TR-DNA fragments into the plant genome. In this study, regenerated plants of Cg did not contain TR-DNA, indicating that a selective pressure against this T-DNA fragment may exist in Campanula. 相似文献
7.
Marie-Louise Nilsson Henrik Kylin Peter Sundin 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(2):57-65
The recirculation of plant nutrients from urban areas to agriculture and horticulture and a need to reduce waste disposal by landfilling and incineration are the main reasons for recycling the biologically degradable fraction of household waste. However, before using the recycled material in agricultural and horticultural production it is necessary to make sure that the material does not contain any unwanted contaminants. In general, there is a lack of knowledge about organic contaminants in the degradable fraction of household waste and its compost and anaerobic digestion products. As a first step in a study of organic contaminants in household waste, and as part of the characterization of the degradation processes during composting and anaerobic digestion, the major extractable organic compounds were identified in the biologically degradable fraction of fresh, composted and anaerobically digested household waste. The organic compounds were isolated by supercritical fluid extraction using carbon dioxide as extraction medium. Gas chromatography-mass spectrometry was used for qualitative analyses. Natural products, such as fatty acids, fatty acid esters, n-alkanes, aliphatic alcohols, monoterpenes and triterpenes constituted the major organic components in the waste samples. In addition bis-(2-ethylhexyl) phthalate, frequently used as a plasticizer in polymers, was found in the extracts. In the chromatograms of the extracts of the fresh and composted household waste, fatty acids and fatty acid esters dominated with respect to peak heights and the number of peaks identified. In the anaerobically digested household waste n-alkanes were the dominating compound class. The pattern of the n-alkanes, also found in the fresh waste, possibly indicates a petrogenic origin of these compounds, perhaps caused by contamination during the collection of the household waste. 相似文献
8.
Tarnow I Kristensen AT Texel H Olsen LH Pedersen HD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(5):680-686
With aggregometry, increased platelet activity has been reported in Cavalier King Charles Spaniels (CKCS) without mitral regurgitation (MR). In contrast, dogs with MR have been found to have decreased platelet activity. The purpose of this study was to test an easy bedside test of platelet function (the Platelet Function Analyzer [PFA-100]) to see if it could detect an increase in platelet activity in CKCS without MR and a decrease in platelet activity in CKCS with MR. This study included 101 clinically healthy dogs > 1 year of age: 15 control dogs of different breeds and 86 CKCS. None of the dogs received medication or had a history of bleeding. The PFA-100 evaluates platelet function in anticoagulated whole blood under high shear stress. Results are given as closure times (CT): the time it takes before a platelet plug occludes a hole in a membrane coated by agonists. The CT with collagen and adenosine-diphosphate as agonists was similar in control dogs (median 62 seconds; interquartile interval 55-66 seconds) and CKCS with no or minimal MR (55; 52-64 seconds). The CT was higher in CKCS with mild MR (regurgitant jet occupying 15-50% of the left atrial area) (75; 60-84 seconds; P = .0007) and in CKCS with moderate to severe MR (jet > 50%) (87: 66-102 seconds; P < .0001). CKCS with mild, moderate, and severe, clinically inapparent MR have decreased platelet function. The previous finding of increased platelet reactivity in nonthrombocytopenic CKCS without MR could not be reproduced with the PFA-100 device. 相似文献
9.
Pedersen KM Butler MA Ersbøll AK Pedersen HD 《Journal of the American Veterinary Medical Association》2002,221(5):646-650
OBJECTIVE: To determine accuracy of an oscillometric blood pressure monitor used over a wide range of pressures in anesthetized cats. DESIGN: Prospective study. ANIMALS: 6 healthy cats. PROCEDURE: 4 female cats and 2 male cats that weighed 2.7 to 4.5 kg (5.9 to 9.9 lb) and were 2 to 8 years old were anesthetized. Blood pressure was measured directly with an arterial catheter placed in the right femoral artery and indirectly from the left antebrachium by use of an oscillometric monitor. A series of diastolic arterial pressure (DAP), mean arterial pressure (MAP), and systolic arterial pressure (SAP) measurements were obtained during hypotension, normotension, and hypertension. Values obtained indirectly and directly were compared. RESULTS: The oscillometric monitor was accurate for DAP and MAP throughout the entire pressure range and met the standards of the Association for the Advancement of Medical Instrumentation (mean +/- SD difference from values obtained directly, < or = 5 +/- 8 mm Hg). The SAP was increasingly underestimated with increasing overall pressure; mean differences from direct measurements were -5.2, -12.1, and -17.7 mm Hg during hypo-, normo-, and hypertension, respectively. Standard deviations for SAP were all < or = 8 mm Hg. The monitor gave readings during all attempts. The direct blood pressure recording system appeared to perform well with neither under- nor overdamping. CONCLUSIONS AND CLINICAL RELEVANCE: Except for a minor underestimation of SAP during normo- and hypertension, the oscillometric monitor yielded reliable and easily obtainable blood pressure measurements in anesthetized cats. 相似文献
10.
Most palms used in agroforestry systems are exploited from wild stands or are only occasionally cultivated, while only a few
palms have been domesticated. In this study we investigated how socio-economic factors and people's perceptions of changes
in palm use and availability, influenced palm cultivation among indigenous Shuar and mestizo settlers in south-eastern Ecuador.
We also looked at how different uses of palms influenced which species they cultivated. Our results showed that perceptions
of declining palm availability in combination with heavy reliance on palm products was positively related to palm cultivation.
Hence, cultivation was more common in more remote villages where alternative products were hard to get. In addition, palm
cultivation was more common among wealthier people and among indigenous people than among recent settlers. This points to
a limiting role of assets such as land and to the importance of history and culture with regard to cultivation. It was not
possible to identify any single palm use as the primary reason for cultivating a species, but the more uses a species had,
the more likely it was to be cultivated. These findings have important implications for development projects that promote
cultivation of palms and other long-lived tree crops. They illustrate how market access and lack of necessary assets may undermine
cultivation of native species even though these are regarded as important resources. 相似文献