Diversity of the European indigenous wild apple (Malus sylvestris (L.) Mill.) in the East Ore Mountains (Osterzgebirge), Germany: II. Genetic characterization

In the present study genetic diversity and hybridization with cultivars were investigated in a population of the endangered European wild apple species Malus sylvestris (L.) Mill. with the aim to establish a basis for the implementation of conservation activities and to ensure its long-term preservation. A total of 284 putative M. sylvestris trees located in the East Ore Mountains were investigated along with a standard set of reference apple genotypes proposed by the European Cooperative Program for Plant Genetic Resources (ECPGR) and 13 old apple cultivars often cultivated in Saxony. The genetic analysis was performed using 12 microsatellite markers also recommend by the ECPGR. To differentiate ‘true type’ M. sylvestris individuals, hybrids and apple cultivars (Malus × domestica Borkh.) a model-based cluster analysis was performed using STRUCTURE. Two clusters were identified consisting of M. sylvestris and M. × domestica genotypes. About 40 % of the putative M. sylvestris showed an admixture of the species-specific allele frequencies and were defined as hybrids. The genetic diversity of the ‘true type’ M. sylvestris population was still high but slightly lower than in the apple cultivars especially since some SSR loci were fixed on one or few alleles in the M. sylvestris population. The differentiation parameters between ‘true type’ wild apple and cultivars indicated a clear discrimination between the wild and cultivated apple individuals. This fact confirms our expectation of the existence of ‘true type’ M. sylvestris individuals in the East Ore Mountains and argues for the realization of preservation measures in this area.     

Zum verbleib des düngemittelstickstoffs im verlaufe der winterroggen-vegetation: For the comparison of nitrogen fertilizer in the course of winter rye vegetation

In the Static Nutrient Deficiency Trial Thyrow (weak silty sand) 3 trial blocks were selected: without fertilizer, NPK?+?lime and NPK?+?lime?+?manure. They differ in nutrient content and graduate themselves considerably in the content of organic soil substance. In the field plots there are micro plots with the nitrogen stages 60, 120 and 160?kg ha^??1, as the ¹⁵N marked ammoniumsulfat becomes incorporated. The nitrogen fertilizer of the first input only migrated 0?–?10?cm deep into the layer of the ground. Next to the plant N-intake it is defeated considerably by an apparent nitrogen immobilisation in the soil. The second nitrogen input is directly received by the plant and is affected by a nitrogen establishment; as it is a mineral nitrogen, also in the upper crumb lay, hard to prove. Against that the soil-born nitrogen is distributed above the depth, here until 60?cm, and becomes increasingly assimilated in the second vegetation half by rye. The yield increase during the vegetation, corn and straw yield for the harvest time follows the soil quality (trial blocks) as well as the actual fertilizer use. The nitrogen from the fertilizer pool corresponds a polynom 2, degrees, while the nitrogen in the soil is subjected in the nitrogen intake of a linear function. For the harvest the nitrogen uptake (grain and straw) form both, soil and fertilizer-N, in the variant NPK?+?lime?+?manure is the biggest.     

Die wirksamkeit des nitrifikationshemmers dimethylpyrazolphosphat zu winterroggen auf sandboden

Auf einem schluffigen Sandboden mit einem C_org‐Gehalt von 600 mg 100 g^?1 Boden wurde ein einjähriger Freilandmodellversuch mit Winterroggen durchgeführt. Die Kleinparzellen (50×50 cm) wurden mit umgerechnet 120 kg ha^?1 N als Ammonsulfatsalpeter einmalig bzw. in geteilter Gabe von 80+40 kg ha^?1 N gedüngt. Die Gesamt‐ und Teilgaben des Mineraldüngers waren wechselseitig mit dem Stabilisotop ¹⁵N markiert und mit dem Nitrifikationsinhibitor 3,4‐Dimethylpyrazolphosphat (DMPP, Handelsname ENTEC^®) formuliert.

Mit Beginn des Schossens setzte die Differenzierung des Biomassezuwachses gegenüber ungedüngt ein. Im Vergleich zum Standard 60 + 40 + 20 kg ha^?1 N (=100%) war der Kornund Strohertrag der 0‐Variante nur 33 bzw. 37%. Ein signifikanter Mehrertrag erzielte das Prüfglied einmalige Gabe von 120 kg ha^?1 N. Alle anderen Varianten haben sich biostatistisch nicht unterschieden.

Die Nitrifikationsverzögerung ist nach 6 Wochen beendet. Bei der 2. N‐Gabe wurde keine Wirkung durch DMPP erreicht. Der Inhibitor hat die apparente ¹⁵N‐Immobilisation erhöht, der DMPP‐Effekt betrug bis zu 24% der Dünger‐N‐Anwendung. In der Folge war zwischenzeitlich auch die Dünger‐N‐Ausnutzung bis 25% geringer. Schließlich war im N‐Entzug der DMPP‐Varianten der Anteil von Boden‐N relativ größer und in den DMPP‐freien Prüfgliedern der Anteil von Dünger‐N relativ höher.     

More sex at higher altitudes: Changes in the frequency of parthenogenesis in oribatid mites in tropical montane rain forests

We investigated changes in density, proportion of parthenogenetic species and individuals, and community structure of oribatid mites (Oribatida, Acari) along an altitudinal gradient in tropical montane rain forests in southern Ecuador. We hypothesized that the proportion of parthenogenetic species and individuals increases whereas density decreases with increasing altitude due to increased harshness of abiotic conditions known to favor parthenogenetic reproduction. In contrast to our hypothesis, the number of parthenogenetic species and individuals decreased toward higher altitudes indicating that changes in environmental conditions with altitude favor sexual rather than parthenogenetic reproduction. Low density of oribatid mites at high altitudes suggest that high frequency and density of sexual species is favored by the availability of resources and not by factors related to harsh abiotic conditions, finding mating partners or tight coupling with parasites or pathogens. Cosmopolitan decomposer taxa tended to be more frequent at higher altitudes indicating that these species are euryoecious. Overall, our data support the view that the reproductive mode of soil animals is predominantly controlled by the availability and accessibility of resources.     

Usefulness of near‐infrared spectroscopy for the prediction of chemical and biological soil properties in different long‐term experiments

The prediction accuracy of visible and near‐infrared (Vis‐NIR) spectroscopy for soil chemical and biological parameters has been variable and the reasons for this are not completely understood. Objectives were (1) to explore the predictability of a series of chemical and biological properties for three different soil populations and—based on these heterogeneous data sets—(2) to analyze possible predictive mechanisms statistically. A number of 422 samples from three arable soils in Germany (a sandy Haplic Cambisol and two silty Haplic Luvisols) of different long‐term experiments were sampled, their chemical and biological properties determined and their reflectance spectra in the Vis‐NIR region recorded after shock‐freezing followed by freeze‐drying. Cross‐validation was carried out for the entire population as well as for each population from the respective sites. For the entire population, excellent prediction accuracies were found for the contents of soil organic C (SOC) and total P. The contents of total N and microbial biomass C and pH were predicted with good accuracy. However, prediction accuracy for the other properties was less: content of total S was predicted approximately quantitatively, whereas Vis‐NIR spectroscopy could only differentiate between high and low values for the contents of microbial N, ergosterol, and the ratio of ergosterol to microbial biomass C. Contents of microbial biomass P and S, basal respiration, and qCO₂ could not be predicted. Prediction accuracies were greatest for the entire population and the Luvisol at Garte, followed by the Luvisol at Hohes Feld, whereas the accuracy for the sandy Cambisol was poor. The poor accuracy for the sandy Cambisol may have been due to only smaller correlations between the measured properties and the SOC content compared to the Luvisols or due to a general poor prediction performance for sandy soils. Another reason for the poor accuracy may have been the smaller range of contents in the sandy soil. Overall, the data indicated that the accuracy of predictions of soil properties depends largely on the population investigated. For the entire population, the usefulness of Vis‐NIR for the number of chemical and biological soil properties was evident by markedly greater correlation coefficients (measured against Vis‐NIR predicted) compared to the Pearson correlation coefficients of the measured properties against the SOC content. However, the cross‐validation results are valid only for the closed population used in this study.     

Classical swine fever virus isolates from Cuba form a new subgenotype 1.4

Identification and classification of classical swine fever virus (CSFV) on the basis of nucleotide sequencing and phylogenetic analysis have become an important tool to study the epidemiology and to control CSF disease. According to phylogenetic analyses of short sequences from the 5′nontranslated region (150 nt) and the E2 (190 nt), most CSFV isolates from South and Central America have been assorted to the subgenotypes 1.1 and 1.3, while CSFV isolates from Cuba have been allocated to subgenotype 1.2. Here we demonstrate that determination and comparison of full-length E2 sequences as well as of the sequences encoding for N^pro, C, E^rns, E1 and E2 (3361 nt) do not support segregation of Cuban CSFV isolates to subgenotype 1.2. In fact, our analysis revealed that the Cuban isolates are more divergent from other so far known CSFV subgenotype 1 isolates and form a novel separate subgenotype that is proposed to be designated subgenotype 1.4.     

Moving beyond the opposition of diverse knowledge systems for food security and nutrition

Food Security and Nutrition(FSN) is influenced by diverse and complex factors, and therefore requires a holistic approach to agriculture and food systems plus integration of knowledge from diverse sources in science and society. Using the results of a colloquium held at the University of Hohenheim(Germany) in September 2016 leading up to the recent High Level Panel of Experts(HLPE) Note on Critical and Emerging Issues for Food Security and Nutrition, this article underlines the role of research and innovation as a social and political process and draws attention to neglected types of knowledge. It illustrates the potential of knowledge co-production and co-innovation to transform food systems in order to achieve the Sustainable Development Goals.     

Effect of replacement of fish oil with camelina (Camelina sativa) oil on growth, lipid class and fatty acid composition of farmed juvenile Atlantic cod (Gadus morhua)

Camelina (Camelina sativa) oil was tested as a replacement for fish oil in diets for farmed Atlantic cod (Gadus morhua). Camelina differs from other plant oilseeds previously used in aquaculture with high lipid (40 %), α-linolenic acid (40 %), antioxidants and low proportions of saturated fats. Dietary treatments were fed to cod (19 g fish^?1 initial weight) for 9 weeks and included a fish oil control (FO), 40 % (CO40) and 80 % (CO80) replacement of fish oil with camelina oil. There was no effect of replacing fish oil with camelina oil included at levels up to 80 % on the growth performance. Cod fed CO80 stored more lipid in the liver (p < 0.01), including more neutral lipid (p < 0.05) and triacylglycerol (p < 0.05). Cod fed CO80 decreased in total polyunsaturated fatty acids (PUFAs) in muscle compared to CO40 and FO (p < 0.05), increased in monounsaturated fatty acids (p < 0.01), decreased in total ω3 fatty acids (FO > CO40 > CO80; p < 0.01) and increased in total ω6 fatty acids (FO < CO40 < CO80; p < 0.01). In the liver, long-chain (LC) PUFA such as 20:4ω6, 20:5ω3, 22:5ω3 and 22:6ω3 decreased when fish oil was removed from the diet (p < 0.05), and increased in 18-carbon fatty acids (p < 0.01). Camelina oil can reduce the amount of fish oil needed to meet lipid requirements, although replacing 80 % of fish oil reduced LC PUFAs in both tissues. A comparison of BF₃ and H₂SO₄ as catalysts to transmethylate cod liver and muscle lipids revealed small but significant differences in some fatty acid proportions.     

Report on the 42nd joint meeting of the DPG-working group Nematology and the working group “free living nematodes”

Journal of Plant Diseases and Protection -     

Improved strategy for phylogenetic analysis of classical swine fever virus based on full-length E2 encoding sequences

ABSTRACT: Molecular epidemiology has proven to be an essential tool in the control of classical swine fever (CSF) and its use has significantly increased during the past two decades. Phylogenetic analysis is a prerequisite for virus tracing and thus allows implementing more effective control measures. So far, fragments of the 5′NTR (150 nucleotides, nt) and the E2 gene (190 nt) have frequently been used for phylogenetic analyses. The short sequence lengths represent a limiting factor for differentiation of closely related isolates and also for confidence levels of proposed CSFV groups and subgroups. In this study, we used a set of 33 CSFV isolates in order to determine the nucleotide sequences of a 3508-3510 nt region within the 5′ terminal third of the viral genome. Including 22 additional sequences from GenBank database different regions of the genome, comprising the formerly used short 5′NTR and E2 fragments as well as the genomic regions encoding the individual viral proteins Npro, C, Erns, E1, and E2, were compared with respect to variability and suitability for phylogenetic analysis. Full-length E2 encoding sequences (1119 nt) proved to be most suitable for reliable and statistically significant phylogeny and analyses revealed results as good as obtained with the much longer entire 5′NTR-E2 sequences. This strategy is therefore recommended by the EU and OIE Reference Laboratory for CSF as it provides a solid and improved basis for CSFV molecular epidemiology. Finally, the power of this method is illustrated by the phylogenetic analysis of closely related CSFV isolates from a recent outbreak in Lithuania.