Development and Validation of a Fast PCR-Based Detection Method for Pathogenic Isolates of the Citrus Black Spot Fungus, Guignardia citricarpa     

Peter J.M. Bonants  George C. Carroll  Marjanne de Weerdt  Ilse R. van Brouwershaven  Robert P. Baayen 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(5):503-513

Based on the ITS regions of the ribosomal DNA, specific primer sets were developed for the citrus pathogen Guignardia citricarpa and the common citrus endophyte, G. mangiferae, and tested for their specificity against 37 isolates of G. citricarpa, 29 isolates of G. mangiferae, 10 isolates of related species and other fungi found on citrus. The efficacy of the PCR-detection method for G. citricarpa was approximately 60–70% for lesions without pycnidia, and approximately 90% for lesions with pycnidia. A reliability of 99% can be reached by analysing multiple lesions per sample. An internal control was developed to monitor DNA samples for PCR inhibition; samples with PCR inhibition should be re-examined. Detection by PCR is more rapid than the current five-day incubation method prescribed by the European Union for diagnosis of black spot lesions lacking the diagnostic pycnidia. The latter method had an efficacy of 40–50%, while culturing of suspected lesions had an efficacy of 10%. Species-specific primers and ITS sequence data showed that G. citricarpa can occur as a symptomless endophyte in leaves. This shows that wild and cultivated plants occurring in citrus groves are potential carriers of this quarantine fungus. Application of the presently developed PCR method for the detection of G. citricarpa will enable citrus producing as well as importing countries to prevent further spread of this harmful organism.  相似文献   

Pectobacterium aroidearum and Pectobacterium carotovorum subsp. carotovorum as causal agents of potato soft rot in Lebanon     

Chiaraluce Moretti  Rim Fakhr  Chiara Cortese  Paul De Vos  Martina Cerri  Leila Geagea  Ilse Cleenwerck  Roberto Buonaurio 《European journal of plant pathology / European Foundation for Plant Pathology》2016,144(1):205-211

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Cerebellar Purkinje's Cell Degeneration and Coat Color Dilution in a Family of Rhodesian Ridgeback Dogs     

Carla Chieffo  Ilse H. Stalis  Thomas J. Van  Winkle  Mark E. Haskins  Donald F. Patterson 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(2):112-116

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Vasopressin response to osmotic stimulation in 18 young dogs with polyuria and polydipsia     

van Vonderen IK  Kooistra HS  Timmermans-Sprang EP  Meij BP  Rijnberk A 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2004,18(6):800-806

Common disorders of water homeostasis leading to polyuria include a variety of endocrine, metabolic, and renal disturbances. After exclusion of most of these conditions, the diagnostic dilemma of differentiating between central diabetes insipidus, primary polydipsia, and nephrogenic diabetes insipidus may remain. Here, we report on 18 young dogs with polyuria that had been present in most cases since the dogs were puppies. The conditions were categorized according to the plasma vasopressin (VP) response to hypertonicity. The VP response to osmotic stimulation was tested by IV infusion of 20% NaCl for 2 hours. The VP response in all dogs was abnormal. Three categories could be distinguished: an exaggerated response (n = 3), a subnormal response (n = 4), and a nonlinear response with high plasma VP concentrations unrelated to increases in plasma osmolality (n = 11). The VP response to hypertonicity did not consistently distinguish among different clinical entities. In the 9 dogs with variations in urine osmolality compatible with primary polydipsia, exaggerated, subnormal, and nonlinear responses were observed. Examination of the present data questions the generally accepted notion that VP measurements during hypertonic saline infusion are the "gold standard" for the diagnostic interpretation of causes of polydipsia and polyuria. Studies of the peripheral reflection in plasma of the pulsatile VP release in healthy and polyuric individuals, with and without osmotic provocation, should be performed.  相似文献   

Growth regulators in fruit production reviewed from ISHS symposia at St. Paul and Long Ashton, 1972     

H. Jonkers 《Scientia Horticulturae》1973,1(3):279-290

The papers of two ISHS symposia, held in 1972, are reviewed. Regarding growth regulators in fruit production, the output of papers on scientific research far exceeds the number of publications on their use in horticultural practice. Only limited information is still available about their mode of action.Hormonal control of fruit growth is best understood in the grape. Gibberellins are widely used to prevent seed formation in grape and to promote fruit set in pears and citrus.One of the most promising chemicals is (2-chloroethyl)phosphonic acid (ethephon) (CEPA). On the other hand, the practical use of abscisic acid (ABA) is nil. A mixture of an auxin, a gibberellin and a cytokinin is used to induce parthenocarpy on apple. Several growth regulators are applied in succesion in a superintensive system of apple growing in Great Britain: the ‘meadow orchard’, a possible breakthrough towards a more mechanised way of fruit growing.  相似文献   

Horticultural reviews,volume 4, 1982: Jules Janick (Editor). Macmillan Press Ltd., London, 280 pp., £25.00. ISBN: 0-333-34192-9     

H. Jonkers 《Scientia Horticulturae》1983,21(2):200

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Testing Koopmann's rules of apple tree pruning     

H. Jonkers 《Scientia Horticulturae》1982,16(3):209-215

Using 2 apple cultivars, 2 of the 3 “Rules of Koopmann” were confirmed in greenhouse experiments. The new terminal was longest after the most severe pruning. Stem thickness was increased most if no pruning occurred. Root growth decreased and stem: root ratio increased with increasing severity of pruning. Cultivars differed in their reaction to pruning.  相似文献