Piscine orthoreovirus (PRV) in red and melanised foci in white muscle of Atlantic salmon (Salmo salar)

Melanised focal changes (black spots) are common findings in the white skeletal muscle of seawater-farmed Atlantic salmon (Salmo salar). Fillets with melanised focal changes are considered as lower quality and cause large economic losses. It has been suggested that red focal changes (red spots) precede the melanised focal changes. In the present work, we examined different populations of captive and wild salmon for the occurrence of both types of changes, which were investigated for the presence of different viruses by immunohistochemistry and RT-qPCR. The occurrence of red or melanised foci varied significantly between the populations, from none in wild fish control group, low prevalence of small foci in fish kept in in-house tanks, to high prevalence of large foci in farm-raised salmon. Large amounts of Piscine orthoreovirus (PRV) antigen were detected in all foci. No other viruses were detected. Red focal changes contained significantly higher levels of PRV RNA than apparently non-affected areas in white muscle of the same individuals. Some changes displayed a transient form between a red and melanised pathotype, indicating a progression from an acute to a chronic manifestation. We conclude that PRV is associated with the focal pathological changes in the white muscle of farmed Atlantic salmon and is a premise for the development of focal melanised changes.     

Distribution of endangered bryophytes in Austrian agricultural landscapes

In Austrian agricultural landscapes, 1936 sampling plots within 72 study sites selected by a random procedure were investigated with regard to their bryophyte vegetation. Out of a total of 506 species, 135 endangered species were recorded. Thirty-eight percent of all populations of endangered species showed sporophytes and 15% produced vegetative reproduction units. There is a significantly higher number of endangered species growing in upland landscapes dominated by moderately intensive cattle farming than in lowland landscapes with a wide range of mainly intensive farming styles. The percentage of species that are endangered is higher in intensively than in moderately used areas. The sampling plots differed strongly in respect to their number of endangered species. Very important habitats for endangered bryophytes are less intensively used vineyards, moderately and less intensively used meadows (including fens), field margins and fallow lands. There is a significant negative correlation between land-use intensity as defined by the hemerobic state and the number of endangered species. The distribution of endangered species according to land-use and habitat quality is discussed.     

Vergleichend-anatomische Untersuchungen im Verwandtschaftskreis vonTriticum L. undAegilops L. (Gramineae)

Zusammenfassung Bei 46 Arten der GattungenTriticum undAegilops wurden anatomische Untersuchungen im Bereich der Organe Wurzel, Halm, Blattspreite, Ährenspindel, Spelzen, Blüte und Karyopse mittels gefärbter Hand- bzw. Mikrotomschnitte vorgenommen. Bedingt durch die kleineren Sproßorgane vonAegilops ergaben sich dort oft geringere Zellgrößen. Häufig waren auch mit der Ploidiestufe korrelierte Merkmale anzutreffen. In einigen Fällen ließ sich der Einfluß bestimmter Arten bzw. Genome auf die Merkmalsausprägung der allopolyploiden Sippen deutlich nachweisen, wofür als besonders klares BeispielAegilops tauschii mit seinem Einfluß auf die hexaploiden Weizenarten und auf die SektionVertebrata der GattungAegilops zu nennen ist. Innerhalb der GattungTriticum konnte eine Beziehung der Weizenarten mit einem G-Genom zu den diploiden Arten dieser Gattung durch Merkmale aller Organe belegt werden, während mit den übrigen Weizenarten weniger Ähnlichkeit besteht. Ein Merkmal im Halmbereich gibt sogar einen Hinweis auf die mögliche Beteiligung vonTriticum urartu an der Evolution der Weizenarten mit dem G-Genom. Nach Blatt- und Spelzenmerkmalen lassen sich die meisten tetraploidenTriticum- Sippen. mit einem AB-Genom zwei verschiedenen Gruppen zuordnen. Die diploiden Weizenarten erwiesen sich als gut charakterisierbare Gruppe. Echte anatomische Unterschiede zwischen Wild- und Kulturweizen bestehen nur in Bezug auf die Brüchigkeit der Ährenspindel. Innerhalb der GattungAegilops stehen sich die SektionenSitopsis undAmblyopyrum sehr nahe und sind auch denTriticum- Sippen viel ähnlicher als die übrigen Vertreter ihrer Gattung. Ein genauerer Hinweis auf den möglichen Donor des B-Genoms läßt sich aber anhand der anatomischen Merkmale nicht geben. Im gesamten Verwandtschaftskreis vonTriticum undAegkilops nur einmal auftretende Merkmale sind sehr selten, jedoch gibt es in mehreren Gruppen relativ isoliert stehende Arten. Zahlreiche anatomische Merkmale sind durch eine so große infraspezifische Variationsbreite gekennzeichnet, daß sie keine phylogenetische Aussage erlauben.

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Anatomical studies within the generaTriticum L. andAegilops L. (Gramineae)

Summary The anatomical characters of the root, culm, leaf lamina, ear rhachis, glume, palea, flower and caryopsis of 46Triticum andAegilops species were examined on the basis of coloured sections, made by hand or by microtome. Due to the smaller organ sizes ofAegilops also the cell sizes are mostly reduced in this genus. Often distinct character proved to be correlated with distinct ploidy levels. In some instances we were able to find a clear influence of distinct species or genomes on the characters of their alloploid taxa, e. g. an influence ofAegilops tauschii on the characters of the hexaploid wheat species and on the remaining species of sectionVertebrata ofAegilops. We found characters in all organs which point to a connection betweenTriticum species with genome G and the diploid wheats. The degree of similiarity to the other wheat species is much less strongly. One anatomical character of the culm indicates even a possible contribution ofTriticum urartu to the evolution of the wheat species with genome G. Most of the tetraploid species ofTriticum, genome AB, can be arranged into two different groups by means of leaf and glume characters. The diploid wheat species are a well characterized group. We were not able to find real anatomical differences between wild and cultivated wheat species besides the brittle ear rhachis. Within the genusAegilops the species of the sectionsSitopsis andAmblyopyrum resemble one another and theTriticum species much more than the other species ofAegilops. By anatomical characters it is not possible to indicate exactly the donor of genome B. Characters, which can be found only one time within the genera studied, are very seldom, but rather isolated species occur in several groups. Many anatomical characters are so variable even within the same species, that these characters can not be evaluated in phylogenetic respect.

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- Triticum L. Aegilops L. (Gramineae)

46 Triticum Aegilops , , , , , . Aegilops . , . ; Aegilops tauschii Vertebrata Aegilops. Triticum , G, , . Triticum urartu , G. Triticum, AB, . , . . Aegilops Sitopsis Amblyopyrum; Triticum, . - , , . , Tritcum Aegilops — , , , . , .

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Herrn Prof. Dr. Drs. h. c.Hans Stubbe zum 75. Geburtstag gewidmet.     

Taxonomy and evolution of cultivated plants: Literature review 1986 1987

Summary Important papers on taxonomy and evolution of cultivated plants published in 1986 and 1987 were compiled and briefly discussed.

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Taxonomic und Evolution der Kulturpflanzen: Litcraturübersicht 1986/1987

Zusammenfassung Wichtige Arbciton übot Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1986 und 1987 wuzden zusammengestolit und kurz kommentiert.

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: . 1986–1987

, 1986 1987 . .

     

Terrestrial liming as a tool to mitigate acidification of Woods Lake,NY

The Soil Liming Model (SLiM) has been used to simulate lake and stream water quality response to different strategies for the application of limestone to subcatchment soils in the Woods Lake, NY watershed. Simulations using doses of 3, 10, or 30 t ha^–1 forecast that a dose in excess of 10 t ha^–1 must be applied to discharge areas in order to sufficiently improve water quality in the lake. At 3 t ha^–1 inlet stream water quality could support fish populations. As expected, treatment effectiveness is strongly influenced by subcatchment hydrologic flow paths. Where shallow flow predominates, soil liming provides a more effective tool for lake water quality improvement. In subcatchments drained primarily by ground water, the effect of liming on water quality is less pronounced albeit of longer duration. Based upon the results of these model simulations, the authors compare results of conventional lake liming to simulated watershed treatment predictions.     

Fulvic acid composition in degraded fenlands

Fulvic acids (FAs) from topsoil and ground water solutions were investigated to discover effects of land use and peat degradation on their molecular chemical composition and thermal properties. The FAs were extracted from three Gleysols under arable land, intensive and extensive grassland, and from three Histosols under alder forest, extensive grassland, and a natural succession in a long‐term (> 200 years) cultivated fen area. Functional groups and molecular subunits of the FAs were investigated by ¹³C Nuclear Magnetic Resonance (¹³C NMR) spectroscopy. Thermal properties and structural molecular subunits were investigated by off‐line pyrolysis, and Pyrolysis‐Field Ionization Mass Spectrometry (Py‐FIMS). The ¹³C NMR spectra showed that the FAs from topsoil solutions had smaller proportions of alkyl C (mean: —8 %) and more aromatic C (mean: + 6 %) than FAs from ground water. This clear differentiation of dissolved FAs in the soil profiles is consistent with Py‐FIMS data which have shown enrichments of lipids in ground water FAs. Furthermore, Py‐FIMS revealed that the FAs from topsoils were richer in phenols + lignin monomers, carbohydrates, as well as mostly aromatic N‐containing compounds. These molecular subunits of FAs, relatively enriched in topsoil, were also the main indicators of land use and peat degradation. For topsoil solutions, the proportions of phenols + lignin monomers and carbohydrates increased stepwise with peat degradation in Gleysols and Histosols. Correspondingly, the thermal properties indicated the incorporation of these compounds into FAs by chemical bonds of larger thermal stability. Statistical evaluation by principal component analysis of Py‐FIMS clearly supported the differentiation of FAs according to the origin from topsoils and ground water, different soil types, and land use and peat degradation. Hence, it is concluded that water soluble FAs can be utilized as objective ecological indicators for soil effects on adjacent ground and surface waters.     

Nitrogen compounds extracted by electroultrafiltration (EUF) or CaCl2 solution and their relationships to nitrogen mineralization in soils

The objective of the investigation was to identify the most important organic N-containing fractions extracted from soils by electroultrafiltration (EUF) or a CaCl₂ solution, respectively, and their importance for nitrogen mineralization. The investigation comprised 19 agricultural and one forest top soil. Net N mineralization was tested in Mitscherlich pot experiments with three treatments: (1) fallow soil without N fertilizer, (2) soil cultivated with rye grass without N fertilizer, (3) soil cultivated with rye grass with N fertilizer. The highest proportion of N in the extracts was the amino N fraction (amino acids + peptides) amounting to approximately 60% of the total N extracted by CaCl₂ and to about 40% of the total N extracted by EUF. The proportion of amino sugars from total N extracted was in average 10% for the CaCl₂ and 5.2% for the EUF extracts. The proportion of heterocyclic N bases derived from nucleic acids amounted in average to 4.8% and 3.6% for the CaCl₂ and EUF extract, respectively. Amino N (amino acids + peptides) were correlated best with net N mineralization (EUF, r = 0.81***, CaCl₂, r = 0.86***). The correlation between amino sugars and net N mineralization was r = 0.55* for the EUF extract and r = 0.49* for the CaCl₂ extract. The heterocyclic N bases did not correlate with net N mineralization. Correlations between Norg extracted by CaCl₂ versus net N mineralization were higher than those obtained by the EUF extract. Net N mineralization was about four times higher in the fallow soils than in the treatment with grass and no N fertilizer. In the treatment with grass + N fertilizer on average no net N mineralization occurred, moreover there was a tendency of N immobilization. It is assumend that in the treatments with grass cultivation, organic C released by roots stimulated the assimilation of mineral N and amino acids by soil microorganisms resulting in a low net N mineralization. Net N mineralization led to a highly significant depletion in the Norg pools and particularly in the amino N and amino sugar pools in the treatment with grass and without N fertilizer. This depletion was particularly evident in the CaCl₂ extracts. The results justify the conclusion that the Norg obtained with both extraction methods originates from a dynamic N pool into which N flows in and out. The amino N extractable with EUF or CaCl₂ is a reliable indicator for the net N mineralization potential of soils.     

Monitoring infection with Piscine myocarditis virus and development of cardiomyopathy syndrome in farmed Atlantic salmon (Salmo salar L.) in Norway

An epidemiological study was carried out in Norway in 2015–2018, investigating the development of infection with Piscine myocarditis virus (PMCV) and development of cardiomyopathy syndrome (CMS) in farmed Atlantic salmon. Cohorts from 12 sites were followed and sampled every month or every other month from sea transfer to slaughter. PMCV was detected at all sites and in all sampled cages, and fish in six sites developed clinical CMS. The initial infection happened between 1 and 7 months post‐sea transfer, and the median time from infection with PMCV until outbreak of CMS was 6.5 months. Generally, fish from sites with CMS had higher viral titre and a higher prevalence of PMCV, compared to sites that did not develop clinical CMS. The virus persisted until the point of slaughter at most (11 out of 12) of the sites. The detection of PMCV in all sites suggests that PMCV is more widespread than previously known. Screening for PMCV as a tool to monitor impending outbreaks of CMS must be supported by observations of the health status of the fish and risk factors for development of disease.     

Effects of chronic sub‐lethal nitrite exposure at high water chloride concentration on Atlantic salmon (Salmo salar,Linnaeus 1758) parr

The present study examined the protective effects of water chloride (Cl^?) towards nitrite toxicity in Atlantic salmon parr during 84‐day long nitrite exposure. Effects on growth, histology, blood indices and gene expression were studied at a fixed nominal Cl^? concentration of 200 mg/L and at several water nitrite concentrations (0, 0.5, 2, 5 and 10 mg/L NO₂^?–N). The specific growth rate was significantly reduced during the first three weeks at a Cl:NO₂^?–N ratio of 21:1, suggesting the activation of coping mechanisms at the later stages of the experiment. No significant effect of nitrite on gill histology and mortality was found. Nitrite accumulated in plasma; however, a Cl:NO₂^?–N ratio of 104:1 or higher prevented nitrite entry. The concentration of NO₂^?–N in plasma was significantly reduced at the end of the study, supporting the hypothesis of coping mechanisms. Cystic fibrosis transmembrane conductance regulator (cftr)‐1 showed a significant up‐regulation at highest nitrite concentration on day 22, and in three of the highest exposure groups at the end of the experiment. Our findings suggest that a Cl:NO₂^?–N ratio above 104:1 should be maintained through episodes of nitrite accumulation in water during the production of Atlantic salmon parr.     

Depressed growth of non‐chlorotic vine grown in calcareous soil is an iron deficiency symptom prior to leaf chlorosis

The development of iron deficiency symptoms (growth depression and yellowing of the youngest leaves) and the distribution of iron between roots and leaves were investigated in different vine cultivars (Silvaner, Riparia 1G and SO4) grown in calcareous soils. As a control treatment all cultivars were also grown in an acidic soil. Only the cultivars Silvaner and Riparia 1G showed yellowing of the youngest leaves under calcareous soil conditions at the end of the cultivation period. All cultivars including SO4 showed severe shoot growth depression, by 50 % and higher, before yellowing started or without leaf yellowing in the cultivar SO4. Depression of shoot growth occurred independently from that of root growth. In a further treatment the effect of Fe‐EDDHA spraying onto the shoot growth of the cultivar Silvaner after cultivation in calcareous soil was investigated. Prior to Fe application plants were non‐chlorotic, but showed pronounced shoot growth depression. Spraying led to a significant increase in shoot length, though leaf growth was not increased. Accordingly, depression of shoot growth of non‐chlorotic plants under calcareous soil conditions and with ample supply of nutrients and water has been evidenced to be at least partly an iron deficiency symptom. We suggest that plant growth only partially recovered because of dramatic apoplastic leaf Fe inactivation and/ or a high apoplastic pH which may directly impair growth. Since growth was impaired before the youngest leaves showed chlorosis we assume that meristematic growth is more sensitively affected by Fe deficiency than is chlorophyll synthesis and chloroplast development. In spite of high Fe concentrations in roots and leaves of the vines grown in calcareous soils plants suffered from Fe deficiency. The finding of high Fe concentrations also in young, but growth retarded green leaves is a further indication that iron deficiency chlorosis in calcareous soils is caused by primary leaf Fe inactivation. However, in future, only a rigorous study of the dynamic changes of iron and chlorophyll concentration, leaf growth and apoplastic pH at the cellular level during leaf development and yellowing will provide causal insights between leaf iron inactivation, growth depression, and leaf chlorosis.<?show $6#>