Chromatidenspaltung beim Merkmal Nematodenresistenz der Kartoffel

Zusammenfassung Aus Untersuchungen zur Vererbung der monogen dominant bedingten Resistenzgegen Pathotyp 1 (=ROI) des KartoffelnematodenGlobodera rostochiensis ergaben sich Hinweise für Chromatidenspaltung. Bei der Schaffung von multiplexen Vererbern der Resistenz sind zahlreiche Testkreuzungen und Resistenzuntersuchungen von Nachkommen notwendig. Für die Ermittlung des Umfangs der Testpopulationen und ihre genetische Zuordnung wurde eine grafische Darstellung erarbeitet.

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Summary Potato clones which are multiplex for monogene dominant resistance toGlobodera rostochiensis must be test-crossed to susceptible partners to determine their genotypes. The following allowances were calculated for the limits of the populations of seedlings to be tested α=5% (risk group 1), \=5% (risk group 2);d=10% (least significant difference). The following values were obtained for chromosome segregation: triplex/quadruplex 35, duplex 215, simplex 320 and nulliplex 35. For chromatid segregation the values were: quadruplex 35, triplex 80, duplex 248, simplex 320 and nulliplex 35. For practical reasons the 95% confidence limits were displayed graphically. From it the following numbers of seedlings to be tested were calculated: between quadruplex/triplex and duplex, 38 for chromosome segregation and 56 for chromatid segregation respectively; between duplex and simplex, 32 for chromosome segregation and 38 for chromatid segregation respectively. Statistical testing of the segregation ratios withX ² and t-test gave for the triplex and duplex cases highly significant deviations from the expected values for chromosome segregation and a good fit for the chromatid segregation.

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Résumé Les clones de pommes de terre présentant une résistance monogénique dominante à hérédité multiple pourGlobodera rostochiensis, ne peuvent être reconnus qu'après hybridation avec des clones sensibles. Le nombre de plantules à tester dans une population a été calculé selon les critères suivants: α=5% (risque de le ordre), β=5% (risque de 2e ordre).d=10% (différence minimale à la probabilité constante de l'hypothèse nulle, considérée comme valable pour la pratique). Les valeurs suivantes ont été obtenues pour la division des chromosomes: triplex/quadruplex 35, duplex 215, simplex 320 et nulliplex 35. Les valeurs pour la division des chromatides sont: quadruplex 35, triplex 80, duplex 248, simplex 320 et nulliplex 35. Pour l'usage pratique, les intervalles de confiance à 95% ont été présentés graphiquement. Les valeurs suivants ont été obtenues pour le nombre minimum de plantules à tester: entre quadruplex/triplex et duplex 38 pour la division des chromosomes et 56 pour celle des chromatides, entre duplex et simplex 32 lorsqu'il s'agit de division des chromosomes et 38 pour celle des chromatides. L'examen statistique des proportions de ségrégation par les testsX ² et t ont donné des écarts hautement significatifs des valeurs théoriques pour les cas de triplex et duplex, lors des divisions des chromosomes, et des valeurs comparables aux espérances, lors des divisions de chromatides.

     

Tomography in veterinary medicine. Possibilities for the application of this x-ray technic demonstrated on the spinal column of a dog

After a short introduction of theoretical principles of tomography, the advantages of this technique--especially the representation of the dog's spinal column--are discussed with five case histories. This technique allows to produce isolated pictures of special parts of the spinal column which may be superpositioned by other body parts like: atlantooccipitalregion (especially dens axis), caudal cervical spine, thoracical spine and lumbosacral region. Particularly the evaluation of the intervertebral spaces, the small vertebral joints and the contours and structures of the vertebrae is enhanced, which is important in tumorous and infectious processes, as well as in fractures and luxations of the vertebrae. Besides the spatial association of certain structures is possible if their localization with conventional x-ray methods and even with exposures in two planes is unsuccessful.     

Comparative evaluation of six different body regions of the dog using analog and digital radiography

In this study the quality of digital and analog radiography in dogs was compared. For this purpose, three conventional radiographs (varying in exposure) and three digital radiographs (varying in MUSI-contrast [MUSI = MUlti Scale Image Contrast], the main post-processing parameter) of six different body regions of the dog were evaluated (thorax, abdomen, skull, femur, hip joints, elbow). The quality of the radiographs was evaluated by eight veterinary specialists familiar with radiographic images using a questionnaire based on details of each body region significant in obtaining a radiographic diagnosis. In the first part of the study the overall quality of the radiographs was evaluated. Within one region, 89.5% (43/48) chose a digital radiograph as the best image. Divided into analog and digital groups, the digital image with the highest MUSI-contrast was most often considered the best, while the analog image considered the best varied between the one with the medium and the one with the longest exposure time. In the second part of the study, each image was rated for the visibility of specific, diagnostically important details. After summarisation of the scores for each criterion, divided into analog and digital imaging, the digital images were rated considerably superior to conventional images. The results of image comparison revealed that digital radiographs showed better image detail than radiographs taken with the analog technique in all six areas of the body.     

Response of potato cell cultures to aluminium and selection of tolerant cell lines

Summary We developed a method for the selection of aluminium-tolerant cell lines by using a liquid medium which more closely simulates acid soil conditions than media used previously. This medium has a pH of 4.8 and contains Al₂(SO₄)₃ instead of Al-EDTA as the selective agent to avoid the toxic effects of EDTA. It is shown that Al₂(SO₄)₃ exhibits a similar toxic effect on the growth of intact plants and cultured cells. With this medium, potato cell lines tolerating 2 mmol/l aluminium have been selected.     

Störung der Krebsresistenz der Kartoffel nach mutagener Behandlung

Zusammenfassung Knollen einer krebsresistenten Sorte wurden mit γ-Strahlen, Nitrosomethylharnstoff und mit beiden Mutagentien kombiniert behandelt. Im Ergebnis traten Nachkommen mit unterschiedlichem Anf?lligkeitsgrad auf. Bei einem Teil ‘normalisierte’ sich die Resistenz in der vM₃ bzw. vM₅. Unter 550 untersuchten Subklonen waren 3 Mutanten (0,55%), die noch nach 6 Prüfjahren (vM₈) Defekte im Resistenzmechanismus zeigten.     

Prevalence and inheritance of canine elbow dysplasia in German Rottweiler

A total of 2114 scores of elbow arthrosis from the official screening programme of the German Rottweiler Breeding Association (ADRK) were analysed in respect of prevalence and genetic disposition. 45.8% showed no signs of arthritis, 40.6% were scored in Grade 1 with minor osteophytes and 13.6% were affected by arthritis of clinical relevance (Grade 2 and 3). REML estimates showed a heritability of 28% and a litter variance of 6.4%. The only significant environmental fixed effect was gender. 39.1% of the male and 51.5% of the female were free from ED which corresponds with 19.2% of the male and only 8.8% of the female in the critical ED classes of Grade 2 and 3. Differences between the years of examination could be explained by genetic gain. Month of birth as well as age at examination, in the range covered by this study, was not significant. It was stated that the effect of bodyweight should be tested before starting a breeding programme.     

EVALUATION OF THE LOWER RESPIRATORY TRACT IN PSITTACINES USING RADIOLOGY AND COMPUTED TOMOGRAPHY

In the last 2¹/₂ years, 288 grey parrot and amazon species with symptoms of respiratory disease clinically were presented to the clinic for avian medicine at the Justus-Liebig-University in Giessen. Ventro-dorsal and latero-lateral radiographs were taken from all birds; radiologic signs of lower respiratory tract disease were noted. Radiographs were normal in 55 of the birds. The results of the radiographic examination for the remaining 233 birds were compared with the necropsy results of terminally ill parrots, with the results of laboratory examinations/endoscopy/and/or with an examination by computed tomography. Thoracic radiographs were evaluated for occurring radiological abnormalities pertaining to the respiratory tract. The frequency of these lesions and their association with a disease process and/or specific etiology was noted.     

Aluminium-tolerant regenrants from potato cell cultures

Summary Cell cultures were developed from dihaploid clones ofSolanum tuberosum L. Selection in cell suspensions as well as plating of cells on selective medium supplemented with 5 mmol Al produced tolerant cell lines. The constancy of Al-tolerance of cell lines was confirmed by culturing the calli for 3 months in Al-free medium and then transferring them back to selective medium. 4 tolerant regenerant clones were obtained which maintained Al-tolerance also after subculture in control medium. Two of the 4 clones that constantly maintained Al-tolerance, originated from cell lines subcultured for 5 months under stress conditions. However, the regeneration rate of these cell lines was low compared with that of lines obtained after a shorter selection period.     

Static and dynamic ultrasonography for the early diagnosis of canine hip dysplasia

Objective : To determine the feasibility of sonographical examination of hip joints in non-sedated puppies and to assess the value of static and dynamic ultrasonography for the early diagnosis of canine hip dysplasia (CHD). Methods : Prospective study was carried out. Five hundred and sixty-six puppies between the ages of 16 and 49 days underwent sonographical determination of the α-angle, joint laxity and distraction value (DV). Sonographical parameters were correlated to conventional radiographic CHD classification in the adult dogs. Results : α-Angles between 74° and 89° (X ±sd=82·8°±2·31°) were measured. Despite the feasibility of sonographical hip assessment in puppies, no statistically significant correlation was found between sonographical determinations of the α-angle, joint laxity, DV and conventional radiographic hip joint classification at the age of 12 to 24 months. Clinical Significance : Results of our study suggest that static and dynamic ultrasonography of hip joints in puppies between 16 and 49 days of age is technically feasible but cannot be recommended for detecting puppies that will develop CHD between the ages of 12 and 24 months.