Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2009
Abstract
In the Nordic strawberry industry only single-cropping cultivars are used. Several everbearing cultivars have been tried, but neither yield nor quality has been satisfactory. In 2005, new everbearing cultivars were collected and an experiment was established in a polyethylene tunnel. Yield and runnering capacity were recorded in two seasons. The cultivars were the English 'Flamenco' and 'Everest', the Dutch 'Elan' and the Norwegian 'Rita', 'Rondo', 'Ridder' and 'Rosa'. Plug plants were planted in double rows on low ridges mulched with plastic at a plant density equivalent to 50,000 plants per ha. A block design with 20 plants per plot and four replicates was used. The field was harvested two to three times a week during the whole season from June until the beginning of October in both years. Berry size was recorded at all harvests while taste and general performance were evaluated using a scale 1-9. In the first year, the everbearing cultivars had significantly higher yield than the single-cropping cultivars due to more inflorescences, but this was levelled out the second year. While the cropping season of the single-cropping cultivars is only about four weeks, the everbearing cultivars were picked from late June until beginning of October, in both years. The highest yields were obtained by 'Everest' (729 and 844 g) followed by 'Rita' and 'Ridder'. The cultivars 'Elan' and 'Rondo' scored highest both in taste and general performance. 'Everest' also performed well, but flavour was not acceptable.
Authors
Leif Sundheim Maria-Luz Herrero Trond Rafoss Brita Toppe May Bente Brurberg Trond Hofsvang Christer Magnusson Anne Marte Tronsmo Bjørn ØklandAbstract
Phytophthora ramorum S. Werres, A.W.A.M. de Cook & W.A. Man in‘t Veld is a newly described Phytophthora-species which is considered to be relatively recently introduced to both USA and Europe from an unknown area, or areas, of origin. The pathogen has a wide host range and causes a complexity of disease symptoms generally grouped into three categories: canker, foliage lesion, and dieback. In Europe the pathogen has been reported in 21 countries, Norway included; predominantly on ornamental plants in nurseries, but also outside nurseries in gardens and semi-natural environment, most often on rhododendrons. The Norwegian Food Safety Authority needs a risk assessment of the pest as basis for an evaluation of a future phytosanitary risk management of P. ramorum, including whether the organism should be regulated as a quarantine pest in Norway. On this background the Norwegian Food Safety Authority, in a letter of 22nd August 2008, requested a pest risk assessment of P. ramorum from the Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM). The pest risk assessment was adopted by VKM"s Panel on plant health (Panel 9) on a meeting 24th June 2009. VKM"s Panel 9 gives the following main conclusions of the risk assessment: 1) P. ramorum is present but not widely distributed in Norway, and the pest is under official control. The outdoors surveys of P. ramorum in Norway have not been conducted systematically over the whole country, and some uncertainty therefore still remains regarding the current distribution of P. ramorum in the PRA area. 2) The overall probability of entry of P. ramorum into Norway and the overall probability of establishment of P. ramorum in Norway are both rated as high with low levels of uncertainty; 3) In the absence of statutory control the probability for P. ramorum to be spread quickly in the PRA area by trade of host plants for planting is rated as high. The uncertainty of this assessment is low; 4) The part of the PRA area where presence of P. ramorum might result in economically important losses (the endangered area) is assessed to be most of the country of Norway, except where the climate is predicted to be unfavourable for the pest. However, this area must be regarded as a maximum estimate for the endangered area. On the other hand, a narrow and very conservative estimate for the endangered area can be defined based on the geographical distribution of highly susceptible host plants in Norway. This area is gardens and parks with Rhododendron spp., Viburnum spp. and F. sylvatica and areas in the wild into which Rhododendron spp. has spread and woods with F. sylvatica. Woods with F. sylvatica is limited to the county of Vestfold and some small areas in the counties of Aust-Agder and Hordaland; 5) P. ramorum is likely to have moderate economic impact on the nurseries in the PRA area with current phytosanitary measures. Without any such regulations P. ramorum is likely to have major economic impact on the nursery industry of the PRA area. The levels of uncertainties of these assessments are low; 6) With current phytosanitary measures P. ramorum is likely to have moderate economic impact on parks and private gardens in parts of the PRA area. Without any such regulations P. ramorum is likely to have major economic impact in the best climatic zones of the PRA area. The levels of uncertainties of these assessments are low; 7) The impact of P. ramorum in coniferous and mixed forests of the PRA area is likely to be minor. The level of uncertainty of this assessment is medium. The impact of P. ramorum in natural and planted deciduous broadleaf forests of the PRA area is likely to be minor due to the scattered and limited distribution of the most susceptible species. The level of uncertainty of this assessment is medium; 8) The non-commercial and environmental consequences to natural environments in the PRA area are likely to be moderate. The level of uncertainty ...
Authors
Abdelhameed ElameenAbstract
Abstract Germplasm characterization is an important component contributing to the effective management of plant genetic resources. The goal of this thesis was to study the genetic diversity of two models of vegetatively propagated plant species; roseroot (Rhodiola rosea L.) and sweet potato (Ipomoea batatas (L.) Lam), based on germplasm collections. Roseroot was recently collected from natural habitats and then vegetatively propagated at the germplasm centre while sweet potato already has a long tradition as a vegetatively propagated food species. I. Roseroot (Rhodiola rosea) Roseroot, R. rosea, also commonly known as golden root or arctic root, is a perennial herbaceous plant of the Crassulaceae family. R. rosea has its origin from the cold, humid regions of the northern hemisphere and grows mostly in the mountains near the snow border. R. rosea is widely distributed in Norway. As part of an effort to identify commercially valuable genotypes characterization of a germplasm collection from Norway was initiated. Amplified Fragment Length Polymorphism (AFLP) analysis was used to estimate genetic diversity within the Norwegian R. rosea germplasm collection. AFLP analysis of 97 R. rosea clones using five primer combinations gave a total of 109 polymorphic bands. A large molecular marker variation was found among roseroot clones in Norway with an average percentage of polymorphic bands (PPB) of 82.3%. Analysis of molecular variance (AMOVA) revealed a significantly greater variation within regions (92.03%) than among regions (7.97%) demonstrating that there was no close genetic similarity among clones originating from the same county. A low level of genetic differentiation (FST = 0.043) was observed, indicating a high level of gene flow, which had a strong influence on the genetic structure in Norway. Our results indicate high gene flow among R. rosea clones that might be a result of seed dispersal rather than cross-pollination. Ninety five clones of the Norwegian roseroot germplasm collection were analysed and quantified for their content of the bioactive compounds rosavin, salidroside, rosin, cinnamyl alcohol and tyrosol using High Performance Liquid Chromatography (HPLC) analysis. All bioactive compounds were detected in all clones but in highly variable quantities. The frequency distribution of the chemical content of each clone was not correlated with geographic region of origin or gender of the plant. Significant correlations between the content of these bioactive compounds were observed within individual roseroot clones. Low and nonsignificant correlations were found between AFLP markers used to study genetic diversity of the roseroot clones and their content of chemical compounds. The maximum content of rosavin, rosin and salidroside observed were substantially higher than previously reported for roseroot plants, and the roseroot clones characterized in this study might therefore be of high pharmacological value. The large quantitative and qualitative variation of the chemical compounds observed in this study and the large genetic diversity observed in this germplasm constitute a firm basis for improving traits such as chemical composition in a breeding program for roseroot. This is the first report that combines the analysis of genetic diversity with information of the chemical composition of roseroot. Further studies of the roseroot populations from Norway as well as from other countries should be performed throughout the following years to identify clones with optimal chemical compositions and to maintain high genetic diversity of this species. II. Sweet potato (Ipomoea batatas (L.) Lam) Sweet potato has its origin in South America and is the 7th most important crop in the world. A Tanzanian sweet potato germplasm collection was characterized using molecular markers and morphological traits. The AFLP method was used to study the genetic diversity and relationships of sweet potato accessions in the germplasm collection ..
Authors
Karl ThunesAbstract
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Abstract
No abstract has been registered
Authors
Rune Andreassen Hans Geir Eiken J Aspi A Kopatz SG Bjervamoen I Wartiainen C Tobiassen Per Knappskog PE Aspholm ME SmithAbstract
No abstract has been registered
Authors
Rune Andreassen Hans Geir Eiken A Kopatz SG Bjervamoen I Wartiainen C Tobiassen Per Knappskog PE Aspholm ME Smith J AspiAbstract
No abstract has been registered
Abstract
A range of studies the last decade have shown that modified wood can provide excellent protection against a range of wood deteriorating organisms, including decay fungi. However, we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward e.g. inhibition of action of specific enzymes, but they still need testing. An understanding of the mechanisms utilized by decay fungi when exposed to modified wood is important for further optimisation of new modified wood products. In this study gene expression of the brown rot fungus Postia placenta has been monitored after 2, 4 and 8 weeks of colonization in furfurylated Scots pine and control samples. Preliminary results are given. The main finding was that genes related to oxidative metabolic activity was higher in furfurylated wood compared to untreated Scots pine, and that carbohydrate metabolism related expression was lower in furfurylated wood compared to untreated control.
Abstract
Six clones of Rhodiola rosea, obtained from plants originating from widely different areas in Norway, were investigated for their in vitro inhibitory potential on CYP3A4-mediated metabolism and P-gp efflux transport activity. Presumed active constituents in the ethanol extracts of the different clones were quantified. C-DNA baculovirus expressed CYP3A4 and Caco-2 cells were used for inhibitory assays, and as positive control inhibitors ketoconazole and verapamilwere applied, respectively. A validated HPLC methodology was used to quantify the formation of 6-β-OH-testosterone and scintillation counting was used to quantify the transport of 3H-digoxin in Caco-2 cells. All clones showed potent inhibition of CYP3A4 and P-gp activities, with IC50 values ranging from 1.7 to 3.1 μg/mL and from 16.7 to 51.7 μg/ mL, respectively, being below that reported for other herbs and some known classic drug inhibitors, such as St. John’s wort and fluoxetine. Rhodiola rosea might thus be a candidate for clinically relevant drug interactions. The concentration of presumed biologically active constituents in the different clones varied considerably, but this variationwas not related to the clones’ inhibitory potential on CYP3A4 or P-gp activities. Other constituents might thus be responsible for the observed inhibitory properties. The place of origin seemed to be of minor importance for CYP3A4 or P-gp inhibition.
Abstract
No abstract has been registered