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Marianne J. Huisman Erik Jongedijk Dinie Posthumus-Lutke Willink Frank Van Der Wilk Ben J. C. Cornelissen 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(2):29-36
To engineer resistance against potato virus X (PVX), the viral coat protein (CP) gene has been introduced into two potato cultivars. Stable expression of the gene in transgenic clones throughout the growing season has been obtained and resulted in considerably increased virus resistance. With varying frequencies depending on the original cultivar used, true-to-type PVX resistant transgenic clones have been obtained. Since deviant light sprout characteristics were invariably associated with aberrations in plant phenotype, they can be used in procedures to early screen for deviations. Furthermore, it has been possible to unequivocally discriminate between the original untransformed and independent transgenic cultivars. Although no relation has been found between the presence, if any, of the CP of potato virus Y (PVY) or potato leafroll virus (PLRV) in CP gene transgenic potato, appreciable levels of resistance to these viruses has been obtained. This suggests that the mechanism by which a viral CP gene in the potato genome evokes resistance, differs amongst various viruses. 相似文献
23.
R K Frank 《Journal of veterinary diagnostic investigation》2001,13(3):245-249
A large Wisconsin mink (Mustela vison) farm experienced an outbreak of toxoplasmosis in the spring of 1999 following an outbreak of canine distemper during the previous fall. Major clinical signs for pregnant females included reduced feed consumption, abortions, and stillborn kits; kits < or =3 weeks old experienced ataxia and mortality. Of 7,800 females, 1,976 (26%) lost their entire litter either from abortion or neonatal mortality. Kit mortality from 7 days to 3 weeks of age was 3,300, and overall kit mortality attributed to the toxoplasmosis outbreak was 10,408. Six neonatal mink kits, 12 3-week-old kits, and 2 adult female mink were submitted to the University of Minnesota Veterinary Diagnostic Laboratory for diagnostic workup. Gross postmortem lesions were limited to empty stomachs (12 of 12 kits) and pale livers (4 of 12 kits) for the 3-week-old kits. Major microscopic lesions included interstitial pneumonia, encephalitis, encephalomalacia, and myocarditis. Toxoplasmosis was diagnosed by microscopic lesions, microscopic lesion distribution, and the detection of Toxoplasma gondii tachyzoites by immunohistochemistry. This is the first detailed report of an outbreak of toxoplasmosis in mink in the United States. 相似文献
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E Stalber H W Renshaw C Boro D Mattson F W Frank 《Canadian journal of veterinary research》1976,40(1):98-103
A viral agent, designated Id-1, was isolated from the buffy coat of a calf suffering from weak calf syndrome. The virus replicated on bovine salivary gland cells and caused cytopathic effect within four days after infection-Cytopathic effect was characterized by rounding and clumping of cells. Stained preparations of infected monolayers revealed multiple intranuclear inclusions. The agent was found to be resistant to chloroform, ether, trypsin, sodium desoxycholate, oxytetracycline and a pH range of three to nine. The virus was sensitive to 5-iodo-2'-deoxyuridine and to a temperature of 70 degrees C. Cross neutralization tests with Id-1 antiserum and bovine adenovirus type 7 (strain Fujuroi) antiserum resulted in complete neutralilation of both viruses with four or less antibody units of homologous or heterologous antiserum. 相似文献
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Preston C Richling E Elss S Appel M Heckel F Hartlieb A Schreier P 《Journal of agricultural and food chemistry》2003,51(27):8027-8031
By use of extracts prepared by liquid-liquid separation of the volatiles from self-prepared juices of pineapple fruits (Ananas comosus) (n = 14) as well as commercial pineapple recovery aromas/water phases (n = 3), on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the delta(13)C(VPDB) and delta(2)H(VSMOW) values of selected pineapple flavor constituents. In addition to methyl 2-methylbutanoate 1, ethyl 2-methylbutanoate 2, methyl hexanoate 3, ethyl hexanoate 4, and 2,5-dimethyl-4-methoxy-3[2H]-furanone 5, each originating from the fruit, the delta(13)C(VPDB) and delta(2)H(VSMOW) data of commercial synthetic 1-5 and "natural" (biotechnologically derived) 1-4 were determined. With delta(13)C(VPDB) data of pineapple volatiles 1-4 varying from -12.8 to -24.4 per thousand, the range expected for CAM metabolism was observed. Compound 5 showed higher depletion from -20.9 to -28.6 per thousand. A similar situation was given for the delta(2)H(VSMOW) values of 3-5 from pineapple ranging from -118 to -191 per thousand, whereas 1 and 2 showed higher depleted values from -184 to -263 per thousand. In nearly all cases, analytical differentiation of 1-5 from pineapple and natural as well as synthetic origin was possible. In general, natural and synthetic 1-5 exhibited delta(13)C(VPDB) data ranging from -11.8 to -32.2 per thousand and -22.7 to -35.9 per thousand, respectively. Their delta(2)H(VSMOW) data were in the range from -242 to -323 per thousand and -49 to -163 per thousand, respectively. 相似文献
30.
Biochemical study of resistance to imidacloprid in B biotype Bemisia tabaci from Guatemala 总被引:1,自引:0,他引:1
Systemic uptake bioassays using excised cotton leaves confirmed resistance to imidacloprid in a Guatemalan population of the tobacco whitefly Bemisia tabaci Gennadius. Polyacrylamide gel electrophoresis of naphthyl esterases identified the insects as B-types. Upon collection from the field, resistance was determined to be 58-fold relative to a susceptible strain originating in the Imperial Valley of California. Resistance levels increased to 126-fold in this population during its continuous exposure to systemically treated cotton. In biochemical investigations, there was no detectable NADPH-dependent mixed function oxidase metabolism of 14C-imidacloprid at any time during the selection process. In contrast, microsomal preparations from housefly abdomens readily produced significant amounts of the mono-hydroxy and olefin derivatives of the parent compound. Detoxification of imidacloprid by housefly MFOs may account for reports of lower toxicity of the insecticide towards this insect compared with whiteflies, despite similar binding properties between imidacloprid and the nicotinic acetylcholine receptors in both species. 相似文献