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.
2006
Authors
Magnus Karlsson Ari M. Hietala Harald Kvaalen Halvor Solheim Åke Olson Jan Stenlid Carl Gunnar FossdalAbstract
Norway spruce (Picea abies (L.) Karst.) has a natural distribution in the northern parts of Europe and Asia and is economically the most important tree species grown in the Nordic countries. A common threat to Norway spruce is the basidiomyceteous fungus Heterobasidion parviporum Niemelä and Korhonen. H. parviporum mainly attacks Norway spruce, although Siberian fir (Abies sibirica Ledeb.) and Scots pine (Pinus sylvestris L.) occasionally get infected. One obstacle to studying host/pathogen interaction in conifers has been the limited availability of mature clones for controlled inoculations, as genetic variation within the host material and the lack of replicates complicate interpretation of the results. Somatic embryogenesis, rooted cuttings, and tissue cultures may provide solutions for this problem. Tissue cultures from mature Norway spruce trees have been proposed as a possible model system for assessing resistance toward fungal pathogens. Recent data on chitinase isoform activity in the Norway spruce/H. parviporum pathosystem are encouraging; clonal variation was observed in the isoforms affected by inoculation, and the isoforms showing increased band intensity following bark inoculation by H. parviporum were also induced in the inoculated tissue cultures of the corresponding clones. To investigate the biological relevance of tissue cultures in host-pathogen interaction studies, transcript levels of selected host and pathogen genes in tissue cultures of Norway spruce were compared to those in bark of 33-year-old ramets of the same clones upon challenge by the pathogenic fungus H. parviporum. Similar transcript profiles of the pathogen and host genes were observed in both tissues, this supporting the use of tissue cultures as experimental material for the pathosystem. Higher transcript levels of the host genes phenylalanine ammonia lyase, peroxidase, and glutathione-S-transferase were observed in the more resistant clone #589 than in the less resistant clone #409 during the early stages of colonization. The most striking difference between the spruce clones was related to gene transcript levels of a class IV chitinase, which showed a continuous increase in clone #409 over the experimental period, with a possible association of this gene product to programmed cell death. Several of the fungal genes assayed were differentially expressed during colonization, including putative glutathione-S-transferases, laccase, cellulase, cytochrome P450 and superoxide dismutase genes. The transcriptional responses suggest an important role for the antioxidant systems of both organisms.
Abstract
In spring 2002, extensive damage was recorded in southeast Norway on nursery-grown Norway spruce seedlings that had either wintered in nursery cold storage or had been planted out in autumn 2001. The damage was characterised by a top shoot dieback. Two visually distinct types of necroses were located either on the upper or lower part of the 2001-year-shoot. Isolations from the upper stem necroses rendered Gremmeniella abietina, while Phomopsis sp. was isolated mostly from the lower stem necroses. RAMS (random amplified microsatellites) profiling indicated that the G. abietina strains associated with diseased nursery seedlings belonged to LTT (large-tree type) ecotype,and inoculation tests confirmed their pathogenicity on Norway spruce seedlings. Phomopsis sp. was not pathogenic in inoculation tests, this implying it may be a secondary colonizer. We describe here the Gremmeniella – associated shoot dieback symptoms on Norway spruce seedlings and conclude that the unusual disease outburst was related to the Gremmeniella epidemic caused by the LTT ecotype on large Scots pines in 2001. The role of Phomopsis sp. in the tissue of diseased Norway spruce seedlings is yet unclear.
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No abstract has been registered
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No abstract has been registered
Report – Trade Facilitation through Equivalence and Mutual Recognition: The EU Model
Frode Veggeland
Authors
Frode VeggelandAbstract
This report explores how equivalence and mutual recognition have been applied by the European Union (EU) in order to facilitate trade. The EU is of particular interest in this area because it has been in the forefront internationally with regard to applying these tools, both in its internal market project and in its external trade relations. The report includes an empirical mapping of EU’s experience with applying equivalence and mutual recognition as trade facilitating tools. The aim here is to increase the understanding of how these tools can be relevant and important in a wider global context, in particular with regard to food trade. Furthermore, based on this experience some of the challenges that countries are faced with when applying these tools are highlighted thus allowing some assessments of the prospects of and difficulties in achieving trade facilitation through these means. Chapter 2 includes an account of some of the regulatory approaches that the EU has pursued in its attempts at realising an internal market, from the adoption of common rules, to mutual recognition and the «Better Regulation» programme included in the Lisbon strategy. Chapter 3 discusses EU’s rules for third-country relations. Furthermore, some of EU’s mutual recognition and equivalence agreements are explored. In addition to these, Chapter 3 includes an account of one-way judgements of equivalence included in EU’s rules for imports of organic food and fishery products. Chapter 4 presents EU’s work and positions on equivalence and mutual recognition in the WTO and the Codex Alimentarius Commission. Chapter 5 includes an assessment of the EU’s experience with mutual recognition and equivalence. Finally, in Chapter 6 some conclusions and final remarks are made. […]
Authors
Mauro Bernabei Peder GjerdrumAbstract
NOAA Paleoclimatology betjener et World Data Center for Paleoclimatology, herunder en database for årringobservasjoner. Vi har ønsket å gjøre våre observasjoner av barlind fra det italienske Alpe-området allment tilgjengelige gjennom registrering i denne databasen: http://www.ncdc.noaa.gov/paleo/paleo.html Velg Tree-Ring og søk blant tilgjengelige data.
Authors
Lone Ross GobakkenAbstract
No abstract has been registered
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No abstract has been registered
Authors
Sanna Koutaniemi Tino Warinowski Anna Kärkönen Carl Gunnar Fossdal Lars Paulin Stephen Rudd Teemu H. TeeriAbstract
Although a detailed description of the lignin biosynthetic pathway has been established in e.g. Arabidopsis, such an analysis has not been performed in tree species. We have used EST sequencing and quantitative real-time RT-PCR to explore lignin biosynthetic gene expression in Norway spruce (Picea abies).Altogether 7500 ESTs were sequenced from a lignin forming tissue culture and developing wood of spruce, and clustered into 3800 unigenes. According to a tentative annotation, 4% of the unigenes were potentially involved in lignin biosynthesis. For most catalytic steps, several gene family members were found, but only one unigene for each gene family contained ESTs from both the tissue culture and developing wood.Expression of the unigenes was studied in detail using quantitative real-time RT-PCR. Results highlighted the set of unigenes most likely responsible for monolignol biosynthesis in Norway spruce, also demonstrating that the same genes are expressed in all lignin-forming tissues.On the contrary, peroxidases and laccases, thought to be responsible for the oxidative step in lignin polymerisation, had distinct expression profiles in different tissues. Also a few genes induced by compression stress or Heterobasidion annosum infection were identified.
Authors
Håkan Broman Mikael Frisk Mikael Rönnqvist Mikael RönnqvistAbstract
The storm Gudrun hit southern Sweden in January 2005 and approximately 70 million cubic meters of forest was wind felled. The existing logistic planning at forest companies in the damaged area had to be changed over night. There was a direct shortage of both harvest and transportation capacities. Key questions that arised were which terminals to use, where to harvest, where to store, which transportation modes (truck, train, ship) to use. In this paper we describe how the forest company Sveaskog made use of Operations Research (OR) as an important decision support in their supply chain planning in the aftermath of the storm.