Enteric virus pollution of tyrrhenian areas

63 samples (53 seawater and 10 estuarine water samples) of 20 L were obtained during a bathing season from 47 seawater stations and from 1 estuarine station. To determine viral pollution, all samples were subjected to two different methods of viral concentration: tangential ultrafiltration and adsorption-elution with electropositive membranes. Detection of viruses was by cytopathic effect (CPE) in BGM and NA 104 cells. Isolates were identified by dot-blot hybridization and Polyacrylamide Gel Electrophoresis (PAGE). While estuarine water showed enterovirus and/or reovirus presence in 100% of samples, only 14 stations of 47 seawater station samples (30%) showed viral contamination: enteroviruses were isolated from 6 and reoviruses from 8 of the 14 stations. 28 unidentified viruses were detected from seawater in MA104 cells by CPE whereas these viruses were not detected in BGM cells. Enterovirus recovery seems to be better when water samples are concentrated by the tangential ultrafiltration than with absorption-elution with electropositive membranes. For reoviruses and the other viruses the two methods were almost equivalent. BGM cells seem to be more susceptible to enteroviruses, MA104 to reoviruses. Reoviruses failed to indicate enterovirus presence as most of enteroviruses were isolated in waters where reovirus was not observed. Isolated viral species distribution changed during bathing season.     

Screening wild cherry (Prunus avium) for resistance to bacterial canker by laboratory and field tests

Currently, bacterial canker caused by Pseudomonas syringae is a major cause of dieback and tree death in wild cherry (Prunus avium) plantations. The evaluation of breeding collections is needed to produce less susceptible clones or cultivars. Resistance tests were performed using excised shoots (1 and 2 years old) from 79 clones in the laboratory. A subset of 10 clones was also tested in the field. The clones were inoculated with four to seven isolates of a set of 15 isolates of P. s. pv. morsprunorum, P. s. pv. syringae, P. s. pv. persicae, P. syringae pv. avii and P. fluorescens. In the laboratory tests, older and larger shoots were more susceptible. In the field test, size and age of the shoots were not related to girdling by the bacterial canker. Two‐year‐old shoots were best for clonal discrimination. Correlations between 1 and 2‐year‐old shoots were significant but not high. The isolates varied a lot between experiments, but as the clone × isolate interactions were always low, breeding could thus be facilitated. The ranking of clones was conserved quite well between two laboratory tests, but not between two others. Good agreement was found for the best clones in the laboratory tests and in the field test. However, the two worst clones in the latter were among the best in one laboratory test. At least two independent tests in the laboratory are needed to evaluate resistance/susceptibility of clones. Broad sense heritability for resistance varied from 0.27 to 0.51. Although moderate, such heritability clearly encourages a breeding approach to reduce the problem of bacterial canker.     

Plant derived veterinary vaccines

Infectious diseases remain one of the main causes of death and economic losses in animals despite the fact that prophylactic vaccination has been extremely successful in disease prevention. New effective viral, bacterial and parasitic vaccines are needed, but unfortunately production costs still remain prohibitive. In this respect plants can offer a valid alternative. Production of antigenic proteins in plants relies on a well developed and proven technology, several expression platforms are available and many different plant species can be utilized. Plant based veterinary vaccine studies have addressed protection issues in model animals and, more interestingly, some of them have examined the relevant challenge model in the specific species of interest. A general overview of the topic will be outlined together with a few selected promising examples.     

Adventitious root formation in Grevillea (Proteaceae), an Australian native species

Grevillea (Proteaceae) is a native Australian plant genus with high commercial value as landscape ornamentals. There has been limited research on the culture and propagation of Australian native species. The effect of indole-3-butyric acid (IBA) on the rooting of G.‘Royal Mantle’ and G.‘Coastal Dawn’ in winter, spring and summer was evaluated at University of Queensland Gatton, Southern Queensland in order to determine the rooting ability of this species in different seasons. Both Grevillea cultivars showed seasonal rooting. The more difficult-to-root G.‘Coastal Dawn’ had a reduced response to IBA application than G. ‘Royal Mantle’. Stem and leaf indole-3-acetic acid (IAA) levels were not different between cultivars, therefore rooting ability between the two cultivars does not appear to be due to the differences in endogenous IAA levels.     

The European Prunus mapping project Progress in the almond linkage map

Summary Six European research groups are collaborating to develop genetic markers and linkage maps for use inPrunus breeding programmes. A basic map with 200 RFLPs and 50 more markers including isozymes and RAPDs will be constructed using two highly segregating populations: an interspecific peach × almond F₂ and a cherry F₂. Then, the parents of eleven almond, cherry, peach or plum breeding progenies segregating for target characters will be screened for polymorphisms at the marker loci, and a set of reduced maps, one per progeny, will be constructed with markers spaced 20–30 cM and covering the whole genome. Cosegregation analysis of markers and characters of interest will allow us to find linkages between markers and major genes or quantitative trait loci responsible for the expression of these traits. A map with 72 markers, 7 isozymes and 65 RFLPs, has been developed at the IRTA-Cabrils laboratory using an intraspecific almond progeny, ‘Ferragnes’ × ‘Mono’. Probes for the analysis of RFLPs were obtained from almond genomic and cDNA libraries. The level of polymorphism for RFLPs and the distribution of markers in the chromosomes of almond are discussed.     

Water- and pyrophosphate-extractable humic substances fractions as a source of iron for Fe-deficient cucumber plants

The capacity of Fe-deficient cucumber plants to utilise water-extractable and pyrophosphate-extractable humic substances as a source of Fe was investigated. Plants were grown for 13 days in nutrient solution in the presence or absence of Fe and during the last 7 days water-extractable and pyrophosphate-extractable humic substances were added to the solution at a final concentration of 5 μg organic C ml^–1. The water-extractable humic fraction did not significantly modify leaf area and dry matter accumulation, leaf total Fe or chlorophyll content of cucumber plants adequately supplied with Fe. In contrast, pyrophosphate-extractable humic substances caused a slight but significant decrease of all the leaf parameters considered, with the exception of the chlorophyll content. Root Fe content of Fe-sufficient plants was decreased by more than 50% in the presence of each humified fraction. Addition of each humic fraction to Fe-deficient plants led to a partial disappearance of leaf chlorosis symptoms with a significant increase in chlorophyll and leaf Fe content. Fe content of roots was also significantly increased in Fe-deficient plants by the addition of humic substances to the nutrient solution. These results show that Fe-deficient cucumber plants can utilise Fe contained in the two fractions of humified organic matter. However, by calculating the amount of total Fe accumulated per plant in the presence of water-extractable or pyrophosphate-extractable humic substances, it could be seen that Fe contained in the water-extractable humic fraction was almost totally used by Fe-deficient cucumber plants, while that present in the pyrophosphate-extractable fraction could only be partially absorbed. The results strongly support a role of humified organic matter in Fe nutrition of plants and are discussed in terms of a possible interaction between soil humic substances and the biochemical mechanisms involved in the plant response to Fe deficiency. Received: 6 November 1996     

Efficacy of dietary supplementation of fatty acid compound on performance and production in finishing pigs

Tropical Animal Health and Production - The present study was conducted to evaluate the efficacy of dietary supplementation of 0.5 and 1% of fatty acid (FA) compound containing conjugated linoleic...     

Anatomic Observations of the Coronary Sinus in the Dog (Canis familiaris)

The coronary sinus was investigated in 34 normal adult dogs, in order to verify its formation, tributaries, length and the valves, as well as the relationship of the venous walls to the epicardium and to the myocardium. The valve of the coronary sinus was observed in only 4 cases (1.7 %). In 30 cases (98.3 %) the ostium of the coronary sinus was lacking a valve. The valve of Vieussens double, was found at the level of the transition between the great cardiac vein and the coronary sinus, as well as others parietal venous valves. A comparison with the human pattern was made, particularly regarding the action of the valve of the coronary sinus and the formation of the sinus.