Charakterisierung der Virulenz einer Braunrost-Feldpopulation (Puccinia triticina f. sp. tritici) und Nachweis effektiver Braun-rost-resistenz-gene in Weizen (Triticum aestivum)

Puccinia triticina f. sp. tritici, the causal agent of leaf rust causes yield losses in wheat up to 60%. In order to avoid such losses, leaf rust resistance (Lr-) genes have been incorporated into wheat cultivars. The Lr- genes confer mostly vertical resistance, i.e. they are race specific. Therefore, knowledge of still effective resistance genes is required for efficient breeding of resistant cultivars. To get information on these virulences, a leaf rust population was monitored in field experiments in 2010. For this purpose naturally infection at three different timepoints of wheat development was monitored on Thatcher near isogenic lines (NILs) carrying 37 and accessions carrying 6 additional Lr-genes. Thatcher-NILs carrying Lr2a, Lr9, Lr19, Lr22a, Lr23, Lr24, Lr35, Lr38 and Lr49 showed a significantly lower infection with Puccinia triticina than the susceptible cultivar Thatcher. Thatcher-NILs carrying Lr13, Lr16, Lr37 and Lr46 showed no significant differences in comparison to Thatcher. In order to get information on the effectiveness of resistance genes, P. triticina isolates were collected from the NILs analysed in field trials and a leaf segment test was conducted followed by microscopic analyses. In the field and in the leaf segment test Lr9, Lr19, Lr24 and Lr38 and to some extent Lr3a turned out to be the most effective genes. By microscopic analyses, the infection process as well defense reactions activated before macroscopic symptoms are visible were monitored. By counting haustorial mother cells, it could be demonstrated which Lr-genes provide resistance, which were overcame and whether P. triticina isolates exist already at a low frequency, which may overcome a certain Lr-gene in the future. Thus microscopy offers a timesaving and effective method to detect susceptible or resistant plants and the upcoming of virulent races prior to typical symptom expression.     

Milrinone

Milrinone, a positive inotropic drug with vasodilating properties, was administered at doses of 0.5 to 1 mg/kg orally twice daily to 29 dogs with moderate to severe congestive heart failure (CHF). Significant echocardiographic improvement in ventricular systolic function was observed after 3 days of administration of milrinone and at the patients' last echocardiographic observation (day 21 in 25 subjects, day 7 in 2 subjects, and day 3 in 2 subjects). Echocardiographic shortening fraction at the initial measurement had a median increase of 6.14% (P less than 0.001), and for the last observation a 2.83% increase (P less than 0.005). Most patients also showed improvement in their clinical signs as assessed by the veterinarian (72%) and by owner's evaluation (81%). No consistent problem or adverse reaction to milrinone was observed, except for a small number of clinically manageable ventricular dysrhythmias. Milrinone appears in this trial to be effective for the treatment of advanced CHF in dogs.     

Heavy Metal Content of Coho Oncorhynchus kisutch and Chinook Salmon O. tschawytscha Reared in Deep Upwelled Ocean Waters in Hawaii1

Coho (Oncorhynchus kisutch) and chinook salmon (O. tschawyrscha) were reared in seawater pumped from the 600 m depth at the Natural Energy Laboratory of Hawaii. Fish were reared in either 100% deep water at 11 C, or a mixture of 55% deep and 45% surface waters at 17 C. Salmon flesh was analyzed for mercury, zinc, cadmium and lead. Mercury concentration in coho salmon reared at 11 C was significantly lower than the concentration in coho reared at 17 C (P < 0.05), but other heavy metal concentrations in tissue did not differ between the two species or between the two rearing temperatures. Compared with wild salmon from the northwest Pacific Ocean, salmon reared in Hawaii had significantly lower concentrations of mercury and lead (P < 0.05), but significantly higher concentrations of zinc and cadmium. These differences in heavy metal concentration between wild and cultured salmon were most readily explained by differences in the heavy metal content of diets and the lack of heavy metal concentrations in rearing water. The concentration of mercury in salmon tissue was at least 20 times less than the 1.0 μ/g U.S. Food and Drug Administration action level for mercury. Action levels have not been established for zinc, cadmium, and lead.     

Equine thyroid dysfunction.

Hypothyroidism is the most common type of thyroid gland dysfunction reported in horses. Primary, secondary, and tertiary causes of hypothyroidism are discussed. Equine hypothyroidism remains a controversial endocrine disorder because extrathyroidal factors, including the administration of drugs and systemic diseases, affect serum triiodothyronine (T3) and thyroxine (T3) concentrations in horses. Accurate diagnosis of hypothyroidism therefore requires assessment of the hypothalamic-pituitary-thyroid axis. Diagnostic procedures for evaluating thyroid gland function are outlined and results of studies utilizing experimental models are discussed.     

Evaluation of drug-induced prostatic involution in dogs by transabdominal B-mode ultrasonography

The relative antiandrogen-induced prostate involution activity of the newly synthesized hydroxyflutamide pro-drug was compared with that of flutamide in 25 Beagles. Secondary antiandrogen activity of both drugs on the testes and mammary tissue was investigated. Daily oral administration of both compounds at 2 dosages (ie, 2.5 and 5.0 mg/kg of body weight) during a 7-week period was monitored by transabdominal ultrasonography of the prostate twice a week. Cross-sectional area estimates of the prostate gland calculated from oblique dorsoventral, and transverse sonographic measurements were diminished significantly in some of the treated dogs as early as day 14 of drug administration. All treated dogs had significant differences in reduction by day 47. Involution was related directly to dose (P less than 0.05), but no difference was observed between test compounds. Differences in secondary antiandrogen activity were not remarkable. Flutamide was not found to have any activity advantage in vivo over hydroxyflutamide. It was concluded that ultrasonography can be a highly effective means of monitoring prostate size, and of monitoring drug-induced involution over time.     

Antigenic diversity in the major merozoite antigens ofTheileria parasites

Tropical Animal Health and Production -