Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2007
Forfattere
Sanna Koutaniemi Tino Warinowski Anna Kärkönen Edward Alatalo Carl Gunnar Fossdal Pekka Saranpää Tapio Laakso Kurt V. Fagerstedt Liisa K. Simola Lars Paulin Stephen Rudd Teemu H. TeeriSammendrag
Abstract Lignin biosynthesis is a major carbon sink in gymnosperms and woody angiosperms. Many of the enzymes involved are encoded for by several genes, some of which are also related to the biosynthesis of other phenylpropanoids. In this study, we aimed at the identification of those gene family members that are responsible for developmental lignification in Norway spruce (Picea abies (L.) Karst.). Gene expression across the whole lignin biosynthetic pathway was profiled using EST sequencing and quantitative real-time RT-PCR. Stress-induced lignification during bending stress and Heterobasidion annosum infection was also studied. Altogether 7,189 ESTs were sequenced from a lignin forming tissue culture and developing xylem of spruce, and clustered into 3,831 unigenes. Several paralogous genes were found for both monolignol biosynthetic and polymerisation-related enzymes. Realtime RT-PCR results highlighted the set of monolignol biosynthetic genes that are likely to be responsible for developmental lignification in Norway spruce. Potential genes for monolignol polymerisation were also identified. In compression wood, mostly the same monolignol biosynthetic gene set was expressed, but peroxidase expression differed from the vertically grown control. Pathogen infection in phloem resulted in a general upregulation of the monolignol biosynthetic pathway, and in an induction of a few new gene family members. Based on the up-regulation under both pathogen attack and in compression wood, PaPAL2, PaPX2 and PaPX3 appeared to have a general stress-induced function.
Sammendrag
In Norway exterior wood structures have traditionally nearly exclusively been made of treated and untreated Picea abies and Pinus sylvestris. In recent years there has been a tendency that other tree species, like various domestic hardwoods and imported species have been used in exterior above ground applications, often unfinished. For several wood species, especially hardwoods, information regarding the durability in use class 3 is lacking. The main objective of this paper is to evaluate natural durability of Norwegian wood species for above ground applications comparing two non-standard above ground tests with the European standard tests for soil contact (EN 252) and lab performance against basidiomycetes (EN 113). The European standard tests EN 113 and EN 252 gave quite similar results, and they also corresponded well with the natural durability classification in EN 350-2. The two non-standard above ground tests differed to some extend from EN 113, EN 252 and EN 350-2. The results indicate that natural durability classification for one single wood species can change depending on use class. However, the field trials need a longer period of time before a final classification can be performed. Four species not included in EN 350-2 were classified in this study: Juniperus communis (1), Salix caprea (5), Sorbus aucuparia (5) and Populus tremula (5).
Sammendrag
The area of wood protection is in a period of change. New tools are needed to understand the mode of action, and to further improve the new wood protection systems. A set of useful tools are found among the molecular methods. This paper presents an overview of some of the tools available, and the methods are exemplified by papers within the frame of wood protection issues. However, there is still a great unexplored potential within the field of wood protection by the use of various molecular methods. The majority of the work using molecular methods has been performed on species identification issues and within species variation. This paper lists some new promising molecular methods for wood protection issues and a presentation of a new project. The new project will help to gain some new knowledge about how the fungal decay processes are affected by different wood modification systems.
Forfattere
Arne Evjen FønhusSammendrag
Det er ikke registrert sammendrag
Forfattere
Carl Gunnar FossdalSammendrag
Our goal is to study what gene products (mRNA and proteins) are important for trees in order to fend off pathogens. We are interested in the genetic basis of resistance focusing on the molecular basis of both the local and systemic defence responses of trees. So far we have focused on the host defense against necrotrophic fungi and studied the expression and role of defensins, peroxidases, chitinases, CHS, PAL, CAD and a number of other host gene products. Earlier work using clonal trials (in both Sweden and Norway) indicate that there is a genetic basis for resistance to the root-rot causing fungus Heterobasidion annosum s.l.. We have studied the timing and spatial signaling of the defense response in mature Norway spruce trees as well as seedlings and found that the molecular responses differ. Our studies suggest that the time from wounding and infection to induction of defense-related expression is shorter in resistant spruce clones indicating a more efficient host defense response than in susceptible trees.
Forfattere
Carl Gunnar Fossdal Ari M. Hietala Igor A. Yakovlev Halvor SolheimSammendrag
The root-rot causing fungus Heterobasidion annosum senso lato is the most devastating pathogen of conifers in Europe. This pathogen enter Norway spruce trees trough the roots and colonizes the tree from within, growing as a saprophyte when established within the dead heartwood and acting as a necrotroph when in contact with living host tissue. Twenty percent of the trees in Norwegian spruce stands tend to be infected and this pathogen that can colonize ten meters up inside the tree trunk, decaying the silvicultural most valuable part of the tree. Despite this high incidence of damage the tree has efficient defences against this pathogen and the attack is eventually fought off if present in the bark or living wood. The tree also has a defense against this internal attack (by Heterobasidion established in the heartwood expanding and invading outward toward the living sapwood) by forming a reaction zone; in this case the host defense is directed inwardly by the still living sapwood toward the central colonized wood. We have in the last years studied the host responses to infection in Norway spruce clones at the transcriptional level and found that the speed of recognition and that spatial defense signalling appears to be the hallmarks of trees with high degree of resistance. We strive to study both partners in this pathosystem from a molecular perspective, and are now focusing on the pathogen and what fungal gene-products are being expressed during the colonization of the heartwood compared to those expressed close to the active host defense (reaction zone) using suppressive subtractive hybridization (SSH) followed by Real-Time RT PCR analysis. In addition the colonization profiles were followed on extracted gDNA using quantitative Real-Time PCR.
Sammendrag
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Forfattere
Ole Risbøl Arnt Kristian Gjertsen Kjetil SkareSammendrag
A lidar (light detection and ranging) airborne laser scanning project was initiated in 2005, and the results of phase two of this project are presented in this report. The main objective was to test, develop and gradually implement lidar as a method for surveying and monitoring cultural remains in forest areas. As part of the project, a test area comprising 10 square kilometres containing cultural remains, mainly in the form of slag heaps and charcoal pits, was scanned. One of our goals in phase two was to test visual as well as the automatic detection of cultural remains on our terrain models. The visual approach was conducted by means of a simple study of the relief maps and by an approach using the analysis software QT-reader. Generally speaking, a good level of accuracy was achieved by exclusively visual study of the maps. However, results were improved when QT-reader was taken into use. Tests using the pattern recognition methods template matching and Hough-transformation were less successful, and the results suggest that further development is necessary if these, or other pattern recognition methods, are to be successfully used in connection with the survey of cultural remains. At present, lidar is not a satisfactory substitute for field-work if the purpose is to map the total prehistoric use of an area, but it is very suitable where a more large-meshed overview is sufficient. The project will continue to focus on the challenges and limitations associated with this method.
Forfattere
Klaus Mittenzwei Wendy Fjellstad Wenche E. Dramstad Ola Flaten Arnt Kristian Gjertsen Maria Loureiro Sjur Spildo PrestegardSammendrag
In recent years the objectives of agricultural policy have shifted from a principal focus on production and income towards agriculture\"s provision of public goods summarized by the term ‘multifunctionality\". Agricultural sector models, which are important tools for policy advice, need to be adjusted in order to maintain their relevance and reliability in accordance with policy changes. This paper investigates the strengths and limitations of incorporating multifunctionality indicators in the agricultural sector model Common Agricultural Policy Regional Impact Analysis (CAPRI) by reviewing the existing literature and incorporating such indicators in the model. Multifunctionality indicators are developed and implemented for four selected aspects of multifunctionality: food security, landscape, environmental concerns and rural viability. By running different policy reform scenarios, it is shown that indicators closely related to the underlying economic variables of the sector model may provide useful to describe the effects of policy reforms on agriculture\"s multifunctionality. However, these indicators do not completely cover the selected aspects of multifunctionality. In order to yield a broader coverage, this paper proposes to strengthen interdisciplinary research by linking agricultural sector models with other model systems like farm-based economical-ecological models, regional economic models or landscape information systems.
Sammendrag
Det er ikke registrert sammendrag