Untersuchungen zum Nachweis latenter Kontaminationen vonErwinia carotovora var.atroseptica (van Hall) Dye an in vitro-Pflanzen von Kartoffeln     

F. Grimm  B. Baumann 《Potato Research》1991,34(1):47-55

Zusammenfassung Es wurde geprüft, mit welcher Nachweissicherheit in vitro-Klone auf latenten Befall vonErwinia carotovora var.atroseptica (Eca) untersucht werden k?nnen. Als Testmethoden wurden ELISA-daten von in vitro-Pflanzen, Topfpflanzen und Knollen sowie der Bakteriennachweis an in vitro-Proben auf N?hrb?den verglichen. W?hrend die richtige Erfassung Eca-freier Klone mit allen Nachweismethoden fast fehlerfrei gelang, war die Ausgrenzung der positiven Proben mit ELISA teilweise nur mit unzureichender Testsicherheit m?glich. Die N?hrbodentests erwiesen sich als ungeeignet. Die besten Ergebnisse lieferte der ELISA-Knollentest, der aber wegen der Gefahr der Eca-Rekontamination ausscheidet. Aus Ermangelung rationeller Alternativen wird vorerst, trotz schwankender Nachweissicherheit, dem ELISA an in vitro-Pflanzen der Vorzug gegeben. Der Gefahr m?glicher Fehlaussagen wird durch eine mehrfach gestaffelte Kombination von Wiederholungen und Verwendung eines Auswertungsverfahrens mit rechnerischer Grenzwertermittlung entgegengewirkt.

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Summary Erwinia carotovora var.atroseptica (Eca) can survive for many years in tissue culture without signs of bacterial infection on the plants or of it being visible on the medium. Because the infection can be transmitted from one subcultivation to the next, there is a need for appropriate tests to detect latent contamination. Latent infection of in vitro plants, glasshouse plants and tubers by Eca was studied using ELISA and two nutrient media tests in trials to determine the levels of detection which could be achieved. Attempts were made to improve the interpretation of the ELISA results by comparing it with other methods of analysis. The plant material originated from in vitro material of known disease status. Sap samples for ELISA were pressed from whole in vitro plants, pieces from the stem bases of glasshouse plants and the heel-end of tubers. ELISA readings were taken at 405 nm using two photometers. The level used for discriminating between negative and positive results was based on calculating (mean and spread of values respectively). YEB-medium in liquid form and the Luria-Bertani Medium in liquid and solidified (agar) form were the test media (Table 1). Finely cut nodal segments of in vitro plants were placed in liquid media and incubated for five weeks. In vitro leaves which had been pierced were laid on the agar medium. ELISA proved to be inadequate when the results from repeated subcultures were compared (Table 2). The reproducibility of the results varied in sign and value. Readings obtained with negative samples were in better agreement with the disease status of the plants than those from positive ones. Using calculated separation levels gave sharper differentiation in the results than using fixed values. The ELISA results, interpreted on the basis of , varied considerably when applied to in vitro plants in the glasshouse (Fig. 1). Complete detection of the bacteria was only successful in the first test with in vitro plants and in tuber tests. Detection of latent Eca contamination was unsuccessful using the test nutrient media. Only 1 in 116 replicates gave the clouding expected with the nutrient media. There was strong growth of bacteria after two days in all tests with dilutions of pure cultures. False positives did not occur i.e. tests withErwinia-free clones remained clear. On the basis of these results a clear indication of latent Eca contamination on in vitro plants is not possible using ELISA, since the same clones gave positive or negative results depending on the time of testing. The poor reliability of the test must be due to the levels of the pathogen on in vitro plants (10²/g), lower than the detection level of ELISA (10³ cells ml⁻¹). The failure of latent bacteria to grow in the test nutrient media may be due to the attachment of the Eca pathogen to the cell wall structure of the in vitro plants. For reliable detection an enzymatic pre-treatment is presumably necessary, which would allow the pathogen to grow actively in the test media. No improvement of detection levels can be expected using ELISA. Glasshouse grown plants give inconsistent results similar to in vitro cultures. The degree of detection achievable with tuber tests renders it impractical, since the danger of recontamination by Eca during tuber multiplication in the glasshouse is too great. However other approaches to detection described in the literature are either uncertain or too expensive, and it appears that there is no alternative to ELISA for the detection of latent Eca contamination. The possible danger of false results can be counteracted to some extent by the combined use of replication and evaluations based on calculated separation values.

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Volatile compounds emitted by sclerotia of Sclerotinia minor,Sclerotinia sclerotiorum,and Sclerotium rolfsii     

Fravel DR  Connick WJ  Grimm CC  Lloyd SW 《Journal of agricultural and food chemistry》2002,50(13):3761-3764

Volatile compounds emitted by sclerotia of Sclerotinia minor, Sclerotinia sclerotiorum, and Sclerotium rolfsii were identified by solid phase microextraction followed by gas chromatography and mass spectometry. Both S. minor and S. sclerotiorum emitted 2-methylenebornane and 2-methylisoborneol. In addition, S. minor emitted mesityl oxide, gamma-butyrolactone, cis- and trans-linalool oxide, linalool, and trans-nerolidol. S. sclerotiorum emitted 2-methyl-2-bornene, 1-methylcamphene, and a diterpene with a molecular weight of 272. Sclerotium rolfsii did not emit any of these compounds but did emit delta-cadinene and cis-calamenene. Chemicals emitted by S. minor and S. sclerotiorum were tested to determine if they could stimulate germination of conidia of Sporidesmium sclerotivorum, a mycoparasite on sclerotia of Sclerotinia spp. Chemicals were tested at 1 part per billion to 100 parts per million, both in direct contact with conidia and near, but not in, physical contact. None of the chemicals alone nor a combination of all chemicals induced germination of conidia of S. sclerotivorum.  相似文献   

Expression of Leptin and iNOS in Oral Melanomas in Dogs     

V.R. Greene  H. Wilson  C. Pfent  J. Roethele  J. Carwile  Y. Qin  E. Grimm  J.A. Ellerhorst 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2013,27(5):1278-1282

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Effect of Variable Parboiling on Crystallinity of Rice Samples     

J. T. Manful  C. C. Grimm  J. Gayin  R. D. Coker 《Cereal Chemistry》2008,85(1):92-95

Rice parboiled at various combinations of soaking temperature and steaming time were analyzed by differential scanning calorimetry (DSC) and X‐ray diffraction (XRD). Generally, gelatinization enthalpy decreased as the soaking temperature increased from 30°C to 50°C and 70°C to 90°C, and gelatinization enthalpy decreased as steaming times increased from 4 and 8 min to 12 min. As expected, a distinctive A‐pattern was observed in the XRD of raw rice. The most severely parboiled laboratory sample (90°C for 12 min), showed no discernable change toward the V‐pattern. Crystallinity decreased from the raw rice (24.6%) with increased cooking temperature.  相似文献   

Role of ‘<Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter solanacearum’ and <Emphasis Type="Italic">Bactericera cockerelli</Emphasis> Haplotypes in Zebra Chip Incidence and Symptom Severity     

Kylie D. Swisher Grimm  Tariq Mustafa  W. Rodney Cooper  Joseph E. Munyaneza 《American Journal of Potato Research》2018,95(6):709-719

Two haplotypes of the pathogen, ‘Candidatus Liberibacter solanacearum,’ (Lso) and four haplotypes of the insect vector, Bactericera cockerelli, are associated with zebra chip disease of potato. Whether disease severity or incidence is influenced by pathogen or insect haplotype is poorly understood. The role of Lso ‘A’ and ‘B,’ transmitted by three haplotypes of B. cockerelli, on disease severity and incidence in eight potato cultivars was analyzed. Both haplotypes of Lso induced tuber symptoms. In general, Lso B caused higher incidence of symptoms, and greater reduction in tubers compared with Lso A. Lso B was associated with more severe tuber symptoms, producing fewer mild or moderate tuber symptoms. Lso A was associated with less severe tuber symptoms, despite being able to induce severe symptoms. Disease incidence, tuber yield, and symptom severity ratings were not dependent upon the psyllid haplotype transmitting the pathogen, suggesting that pathogen, not insect haplotype affects Lso transmission.  相似文献   

Modelling dead wood islands in European beech forests: how much and how reliably would they provide dead wood?     

Oliver Jakoby  Christine Rademacher  Volker Grimm 《European Journal of Forest Research》2010,129(4):659-668

Dead wood is an important element of forests both for biodiversity and ecosystem functions. Due to intensive silviculture, however, dead wood usually is strongly underrepresented in European forests. Forest reserves cannot fully compensate for this because they comprise only a small proportion of forested areas and are often isolated. Retaining a certain number of dead trees in managed forests is important, but may cause safety problems for lumbermen and visitors and still does not necessarily lead to an amount and incidence (i.e., probability of occurrence) of dead wood that might be required for many species and certain ecosystem functions. Our studies concentrate on a third and complimentary dead wood management strategy: dead wood islands, i.e. small unmanaged islands distributed throughout managed forests. As an example, we focus on European beech forests (Fagus sylvatica). An important question related to this strategy is: how do amount, quality, and incidence of dead wood depend on the island’s size? To provide an answer, we use the spatially explicit, rule-based simulation model BEFORE-CWD that was developed to analyse dead wood dynamics in natural beech forests. This model and its predecessor, BEFORE, are well-verified and validated. They reproduce a suite of observed patterns and generate valid secondary and independent predictions. We found that islands that are too small, i.e. smaller than 0.33 and 0.08 ha for standing and lying dead wood, respectively, can fail to provide dead wood for several decades. The shape of the islands has only a minor effect. Extreme storm events temporarily increase and then decrease the amount of standing dead wood. In terms of the amount and incidence of dead wood, it makes no difference if one big or several small islands are set aside from management, unless the islands are not too small. We conclude that even relatively small unmanaged islands within managed forests can reliably provide dead wood and therefore should be considered as a management option. Our results can be used, for example by using metapopulation models of species of interest, to develop management plans for creating networks of dead wood islands.  相似文献   

Beitrag zur Lösung des „Lärchenrätsels“     

Forstmeister W. Grimm 《European Journal of Forest Research》1937,59(17):540-549

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A review on plant diversity and forest management of European beech forests     

E. D. Schulze  G. Aas  G. W. Grimm  M. M. Gossner  H. Walentowski  C. Ammer  I. Kühn  O. Bouriaud  K. von Gadow 《European Journal of Forest Research》2016,135(1):51-67

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Scientific community. 'Security breach' leaks NIH grant applications onto Web     

Grimm D 《Science (New York, N.Y.)》2005,310(5748):598

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Cardiopulmonary effects of fentanyl in conscious dogs and dogs sedated with a continuous rate infusion of medetomidine     

Grimm KA  Tranquilli WJ  Gross DR  Sisson DD  Bulmer BJ  Benson GJ  Greene SA  Martin-Jimenez T 《American journal of veterinary research》2005,66(7):1222-1226

OBJECTIVE: To determine the hemodynamic consequences of the coadministration of a continuous rate infusion (CRI) of medetomidine with a fentanyl bolus in dogs. ANIMALS: 12 healthy sexually intact male dogs weighing 30.3 -/+ 4.2 kg (mean +/- SD). PROCEDURE: Dogs received either fentanyl alone (15.0 microg/kg, i.v. bolus) or the same dose of fentanyl during an 11-hour CRI of medetomidine (1.5 microg/kg/h, i.v.). Prior to drug administration, dogs were instrumented for measurement of cardiac output, left atrial pressure, and systemic arterial blood pressures. Additionally, blood samples were collected from the pulmonary artery and left atrium for blood gas analysis. RESULTS: Medetomidine infusion reduced the cardiac index, heart rate, and O2, delivery while increasing left atrial pressure. Subsequent fentanyl administration further decreased the cardiac index. The Pao2 was not significantly different between the 2 treatment groups; however, fentanyl transiently decreased Pao2 from baseline values in dogs receiving a CRI of medetomidine. CONCLUSIONS AND CLINICAL RELEVANCE: Because of the prolonged hemodynamic changes associated with the CRI of medetomidine, its safety should be further evaluated before being clinically implemented in dogs.  相似文献