Zur Naturgeschichte des Fischotters

Ohne Zusammenfassung     

Die Rachtheile des Heibe- und Beerfrauts und die zmed. mäkigfte Art und Weife zur Befeitigung besfelben

Ohne Zusammenfassung     

Der Wuchs der Eiche in Abh?ngigkeit von dem Wewicht der Eicheln

Ohne Zusammenfassung     

Canine distemper virus--an agent looking for new hosts

Canine distemper is caused by the canine distemper virus (CDV), a RNA virus belonging to the genus Morbillivirus of the family Paramyxoviridae. The genus Morbillivirus includes measles virus, Rinderpest virus and peste-des-petits-ruminants virus. The host spectrum of CDV, which includes numerous families of Carnivores, has been changed in the last years and distemper-like diseases have been observed in numerous other species. These include epidemics in large felids, marine mammals and javelinas. Different viruses have been isolated from pinnipeds including a seal-specific isolate, termed phocine distemper virus 1, PDV-1, and a CDV strain, named PDV-2. Retrospective analysis of previous epidemics among marine mammals in various regions of the world provide evidence for the occurrence of so far unrecognized morbillivirus epidemics. In some including the mass mortalities of Baikal and Caspian seals and of large felids in the Serengeti, terrestrial carnivores including dogs and wolves have been suspected as a vector for the infectious agent. However, in other epidemics among marine mammals the source of infection remains unknown including both seal epidemics in northwestern Europe in 1988 and 2002. It remains to be determined whether a morbillivirus from other marine mammals or terrestrial carnivores caused the infection in this unprotected seal populations.     

Further Studies on the Presence, Qualities and Effects of the Toxic Principles from Narthecium Ossifragum Plants

Flåøyen, A., Bratberg, B., Frøslie, A., Grønstøl, H., Langseth, W., Mantle, P.G. and Von Krogh, A., 1997. Further studies on the presence, qualities and effects of the toxic principles from Narthecium ossifragum plants. Veterinary Research Communications, 21 (2), 137-148One calf was dosed during one day with an aqueous extract from 3.0 kg (wet weight) of Narthecium ossifragum and another was dosed on the same day with the insoluble plant residue. The concentrations of serum creatinine and magnesium increased only in the calf dosed with the aqueous extract, while the activity of glutamate dehydrogenase increased only in the serum of the calf dosed with the plant residue, so differentiating the nephrotoxic and hepatotoxic principles as water-soluble and water-insoluble compounds, respectively.One calf was dosed with 30 g (wet weight) N. ossifragum flower stems per kg live weight during one day and another was dosed with 30 g (wet weight) N. ossifragum leaves per kg live weight on the same day. The serum creatinine and urea concentrations and also the activities of glutamate dehydrogenase, aspartate aminotransferase and -glutamyltransferase in the serum increased in the calf dosed with the flower stems, whereas there was only a slight temporary increase in the creatinine concentration in serum from the calf dosed with the leaves. However, histopathological examination of the kidneys of the calf dosed with the flower stems revealed severe tubular necrosis and degeneration. It therefore appears that both the toxic principles are present in the flower stems of N. ossifragum rather than in its leaves.The serum creatinine concentration was significantly increased in a non-ruminating calf dosed with an aqueous extract from 32 g (wet weight) N. ossifragum per kg liveweight during one day, showing the intrinsic nephrotoxicity of the plant.     

Storability measures of Norway spruce and Scots pine seedlings and assessment of post-storage vitality by measuring shoot electrolyte leakage

As indoor frozen storage is increasing in forest tree nurseries it is important to have accurate methods for assessing seedling storability in autumn and methods to determine post-storage vitality. Storability of spruce (Picea abies (L.) Karst.) and pine (Pinus sylvestris L.) seedlings can be based on determination of dry matter content (DMC) of seedling shoots or by freezing shoots at –25°C and thereafter measure electrolyte leakage (SEL_diff–25). To compare these two methods we stored 1-year-old spruce and pine seedlings at different occasions during the autumn. To test if leakage of electrolytes from shoots (SEL) could indicate deteriorated vitality, we measured SEL at the end of storage. After storage seedling viability was determined in a three-week growth test, measuring shoot and root growth capacity (RGC). Determination of freezing tolerance (SEL_diff–25) before storage had a better ability to predict the outcome of storage compared to the DMC test. Measuring SEL at the end of the frozen storage period accurately indicated seedling vitality. Seedlings with SEL of 0–5% had a high survival rate whereas SEL over 10% indicated low survival and growth capacity after storage. The SEL method has a potential to become a screening test for identifying batches of seedlings that have been damaged during storage in the nursery.     

Phenotypic differences among three clonal lineages of Phytophthora ramorum

There are three major clonal lineages of Phytophthora ramorum present in North America and Europe named NA1, NA2, and EU1. Twenty‐three isolates representing all three lineages were evaluated for phenotype including (i) aggressiveness on detached Rhododendron leaves and (ii) growth rate at minimum, optimum, and maximum temperatures. Closely related species P. foliorum and P. hibernalis were included in phenotypic tests since these species are encountered in nursery surveys for P. ramorum. Isolates from the NA2 and EU1 lineages were the most aggressive and isolates from the NA1 group were the least aggressive. The NA1 lineage of P. ramorum was the most variable in aggressiveness and growth rate. The variability in the NA1 lineage was due to the presence of non‐wild type (nwt) isolates. There was no significant difference in growth rate among NA1 wild type (wt), NA2, and EU1 lineages at any temperature tested. The difference between wt and nwt P. ramorum isolates is discussed.     

Characterization of resistance genes against scald (Rhynchosporium secalis (Oudem.) J.J. Davis) in barley (Hordeum vulgare L.) lines from central Norway, by means of genetic markers and pathotype tests

Rhynchosporium secalis is a serious pathogen of barley (Hordeum vulgare L.) in central Norway. A breeding effort was initiated in 1977 to introduce resistance from different sources into adapted genotypes, and the first cultivar from the program was recently released. However, little is known about the resistance genes introgressed in this cultivar or in advanced breeding lines. An effort was made to address this issue through a set of isolates and available molecular markers. Fourteen breeding lines and their resistance donors were investigated by evaluating their reactions to 11 R. secalis isolates. Bulked segregant analysis was used to identify molecular markers linked to resistance genes in 12 of the breeding lines. The isolates were found to be of less discriminating value than the markers. Useful information has been obtained as to the nature of several of the resistance genes introgressed. Eight of the 12 breeding lines contained introgressed genes that were located at the `complex Rh' locus on chromosome 3H and hence may not easily be pyramided into the same genotype. Previous information about the nature of the resistance in `Jet' is questioned. Neither of the resistance genes Rh or Rh2 seems to have been incorporated into Norwegian breeding material.