Identification of Resistance Genes Against Powdery Mildew in Four Accessions of Hordeum Vulgare SSP. Spontaneum     

Jana Řepková  Antonín Dreiseitl  Pavel Lízal  Zdeňka Kyjovská  Kateřina Teturová  Radka Psotková  Ahmed Jahoor 《Euphytica》2006,151(1):23-30

Summary Four newly detected accessions of wild barley (Hordeum vulgare ssp. spontaneum) resistant to powdery mildew caused by Blumeria graminis f. sp. hordei were studied with the aim of finding the number of genes/loci conferring the resistance of individual accessions, the type of inheritance of the genes and their relationships to the Mla locus. F₂ populations after crosses between the winter variety ‘Tiffany’ and four wild barley accessions and use of microsatellite DNA markers were focused on the identification of individual resistance genes/loci by means of their chromosomal locations. In PI466495, one locus conferring powdery mildew resistance was identified in highly significant linkage with the marker Bmac0213. This location is consistent with the known locus Mla on chromosome 1HS. In the other three accessions the resistance was determined by two independent loci. In PI466197, PI466297 and PI466461, one locus was identified on chromosome 1HS and three new loci were revealed on chromosomes 2HS (highly significant linkage with Bmac0134), 7HS (highly significant linkage with Bmag0021) and 7HL (significant linkage with EBmac0755). Our prospective aim is identification of further linked DNA markers and the exact location of the resistance genes on the barley chromosomes.  相似文献   

Ancha Srinivasan (ed): Handbook of precision agriculture. Principles and applications     

Anton J. Haverkort 《Euphytica》2007,156(1-2):269-270

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Front-face fluorescence spectroscopy study of globular proteins in emulsions: displacement of BSA by a nonionic surfactant     

Rampon V  Genot C  Riaublanc A  Anton M  Axelos MA  McClements DJ 《Journal of agricultural and food chemistry》2003,51(9):2482-2489

The displacement of a globular protein (bovine serum albumin, BSA) from the surface of oil droplets in concentrated oil-in-water emulsions by a nonionic surfactant (polyoxyethylene sorbitan monolauarate, Tween 20) was studied using front-face fluorescence spectroscopy (FFFS). This method relies on measurement of the change in intensity (I(MAX)) and wavelength (lambda(MAX)) of the maximum in the tryptophan emission spectrum. A series of oil-in-water emulsions (21 wt % n-hexadecane, 0.22 wt % BSA, pH 7.0) containing different molar ratios of Tween 20 to BSA (R = 0-131) were prepared. As the surfactant concentration was increased, the protein was progressively displaced from the droplet surfaces. At R > or = 66, the protein was completely displaced from the droplet surfaces. There was an increase in both I(MAX) and lambda(MAX) with increasing Tween 20 concentration up to R = 66, which correlated with the increase in the ratio of nonadsorbed to adsorbed protein. In contrast, there was a decrease in I(MAX) and lambda(MAX) with Tween 20 concentration in protein solutions and for R > or = 66 in the emulsions, which was attributed to binding of the surfactant to the protein. This study shows that FFFS is a powerful technique for nondestructively providing information about the interfacial composition of droplets in concentrated protein-stabilized emulsions in situ. Nevertheless, in general the suitability of the technique may also depend on protein type and the nature of the physicochemical matrix surrounding the proteins.  相似文献   

Lipid status, paraoxonase-1 activity and metabolic parameters in serum of heifers and lactating cows related to oxidative stress     

M. Anton?i?-Svetina  A. Svetina  B. Reki? 《Research in veterinary science》2011,90(2):298-300

The objective of this study was to investigate serum lipids, metabolic parameters and activity of the anti-oxidative enzyme paraoxonase-1 (PON1). The study was conducted on non-pregnant heifers with optimal health status and on healthy dairy cows in the period of intensive lactation, assuming that the energy and metabolic demands during lactation reduce anti-oxidative protection. Total cholesterol and HDL-cholesterol concentrations were significantly higher (P < 0.05) in lactating cows than in heifers. Bilirubin concentration and γ-glutamyltransferase (GGT) activity were also significantly higher in lactating cows (P < 0.05), indicating increased hepatic efforts of cows to meet energy requirements for lactation. Significantly lower PON1 activity and PON1/HDL ratio in lactating cows compared to heifers (P < 0.05) showed that metabolic efforts during pregnancy, parturition and lactation influence PON1 activity due to oxidative stress. Concurrent increase in total and HDL-cholesterol during lactation indicated that the HDL particle is a major carrier of cholesterol in cows.  相似文献   

Treatment of a coxofemoral luxation in a pony using a prosthetic capsule technique     

Kuemmerle JM  Fürst AE 《Veterinary surgery : VS》2011,40(5):631-635

Objective: To report open reduction and joint stabilization using a prosthetic capsule technique for treatment of a craniodorsal coxofemoral luxation in a lightweight pony. Study Design: Clinical report. Animals: Pony stallion (8 years old, 113 kg). Methods: A craniodorsal approach to the coxofemoral joint was performed under general anesthesia. After open reduction, a prosthetic capsule technique was used. Four 3.5 mm self‐tapping cortical anchor screws were implanted: 2 screws were inserted above the cranial aspect of the dorsal acetabular rim, and 2 screws were inserted into the femoral neck. Subsequently, a #5 USP ultra‐high molecular weight polyethylene suture was placed through these anchor screws in figure‐8 fashion to serve as a prosthetic capsule. Routine closure and a medial patellar desmotomy completed the surgical procedure. Postoperatively, the pony was cross tied for 4 weeks to prevent it from lying down. Results: Neither short‐term nor long‐term complications occurred and the pony was sound at the follow‐up examination performed 15 months postoperatively. Conclusions: A prosthetic capsule technique can be used successfully to stabilize the coxofemoral joint after open reduction of a craniodorsal luxation in a lightweight pony.  相似文献   

The attitudes of minority junior high and high school students toward veterinary medicine     

Asare A 《Journal of veterinary medical education》2007,34(2):47-50

There is a documented lack of racial diversity in veterinary medicine. It has been suggested that lack of animal ownership by minorities, cultural and ethnic biases relating to animals, and a lack of role models of color within the veterinary profession are reasons for the lack of racial diversity in veterinary medicine. The purpose of this study was to survey the attitudes of minority junior high and high school students toward veterinary medicine. It was hypothesized that African American and Latino students in New York City (NYC) would have limited experience with veterinary medicine and would not have a favorable attitude toward the profession. In fact, the survey, which was sent to several NYC schools, found that minority students have a positive view of animals and of veterinary medicine. The survey also showed that a deficiency of minority role models for students, a lack of interest in and enjoyment of veterinary medicine on the part of students, a perception on the part of students that veterinary medicine does not provide a satisfying lifestyle, and inadequate student exposure to the profession are key factors in the lack of racial diversity in veterinary medicine.  相似文献   

Tryptophan-accelerated electron flow through proteins     

Shih C  Museth AK  Abrahamsson M  Blanco-Rodriguez AM  Di Bilio AJ  Sudhamsu J  Crane BR  Ronayne KL  Towrie M  Vlcek A  Richards JH  Winkler JR  Gray HB 《Science (New York, N.Y.)》2008,320(5884):1760-1762

Energy flow in biological structures often requires submillisecond charge transport over long molecular distances. Kinetics modeling suggests that charge-transfer rates can be greatly enhanced by multistep electron tunneling in which redox-active amino acid side chains act as intermediate donors or acceptors. We report transient optical and infrared spectroscopic experiments that quantify the extent to which an intervening tryptophan residue can facilitate electron transfer between distant metal redox centers in a mutant Pseudomonas aeruginosa azurin. Cu(I) oxidation by a photoexcited Re(I)-diimine at position 124 on a histidine(124)-glycine(123)-tryptophan(122)-methionine(121) beta strand occurs in a few nanoseconds, fully two orders of magnitude faster than documented for single-step electron tunneling at a 19 angstrom donor-acceptor distance.  相似文献   

Electric fields due to synaptic currents sharpen excitatory transmission     

Sylantyev S  Savtchenko LP  Niu YP  Ivanov AI  Jensen TP  Kullmann DM  Xiao MY  Rusakov DA 《Science (New York, N.Y.)》2008,319(5871):1845-1849

The synaptic response waveform, which determines signal integration properties in the brain, depends on the spatiotemporal profile of neurotransmitter in the synaptic cleft. Here, we show that electrophoretic interactions between AMPA receptor-mediated excitatory currents and negatively charged glutamate molecules accelerate the clearance of glutamate from the synaptic cleft, speeding up synaptic responses. This phenomenon is reversed upon depolarization and diminished when intracleft electric fields are weakened through a decrease in the AMPA receptor density. In contrast, the kinetics of receptor-mediated currents evoked by direct application of glutamate are voltage-independent, as are synaptic currents mediated by the electrically neutral neurotransmitter GABA. Voltage-dependent temporal tuning of excitatory synaptic responses may thus contribute to signal integration in neural circuits.  相似文献   

Phosphorus Efficiency of Buckwheat (Fagopyrum esculentum)     

Christine Amann  Anton Amberger 《植物养料与土壤学杂志》1989,152(2):181-189

The ability of buckwheat (Fagopyrum esculentum) roots to acquire phosphorus (P) was characterized by investigating P uptake, morphological features, and chemical changes in the rhizosphere. Over a range of nutrient solution P concentrations (5–500 μmol · L^?1), maximum shoot growth was achieved with a P supply between 5 and 100 μmol · L^?1. Root weight and root length, as well as length and frequency of root hairs, were higher at low P levels. Root surface and the root surface/shoot dry weight ratio reached high values. Though P uptake rates were only moderate (0.15 pmol · cm^?1 root · sec^?1), shoot P concentrations were high (1.8% of dry weight with 100 μM P) predominantly being inorganic (80%). Phosphorus efficiency was characterized by a high specific absorption rate (810 mmol P · kg^?1 root dry wt · d^?1) rather than by an efficient utilization for dry weight production. Root exudates of low-P plants had lower pH values than exudates of high-P plants and increased the solubility of FePO₄ and MnO₂ to a greater extent. Amounts of exuded organic acids and phenolics were low and could not account for the observed solubilization of FePO₄ and MnO₂. Enhanced hydrolysis of glucose-6-phosphate by exudates from low-P plants was due to an increased “soluble” acid phosphatase activity, and root surface phosphatase activity was also slightly enhanced with P deficiency. In the rhizosphere soil of buckwheat, some depletion of organic P forms was observed, and in pot trials with quartz sand, buckwheat utilized glucose- 6-phosphate as a P source at the same rate as inorganic P.  相似文献   

Modellanlage zur Bestimmung von Ammoniakverlusten aus organischen und mineralischen Düngern unter kontrollierten Bedingungen     

Klaus Vilsmeier  Martina Rank  Anton Amberger 《植物养料与土壤学杂志》1989,152(5):431-434

A model system for the determination of ammonia losses from organic and mineral fertilizers under controlled conditions A closed-dynamic model was developed for the continuous registration of losses of ammonia. NH₃ escaping from the soil surface is introduced to an acid trap. The resulting increase in pH is equivalent to the amount of NH₃ and is recorded by an automatic data recorder. Wind velocity in this system can be adjusted between 100 and 400 L air/h, which corresponds to a 12 to 40-fold total air exchange per minute. Temperature can be regulated between +5°C and +30°C. In addition, air humidity can be controlled. The testing of the model revealed deviations of maximally 0.6% between measured pH value and destillation. The average recovery amounted to 97.2%.  相似文献