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.
2007
Abstract
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.
Authors
Carl Gunnar FossdalAbstract
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.
Authors
Nicolette Fouche Jolanda Roux Halvor Solheim Ronald N. Heath Gilbert Kamgan Nkuekam P. Chimwamurumbe K.G. Pegg Michael J. WingfieldAbstract
No abstract has been registered
Authors
Lene Frost Andersen Trine Husøy Svein Olav Kolset Henrik Jakobsen Jan Alexander Mona-Lise Binderup Knut Helkås Dahl Erik Dybing Wenche Kristin Farstad Livar Frøyland Ragnhild Halvorsen Margaretha Haugen Kåre Julshamn Georg Kapperud Hilde Kruse Øyvind Lie Anne-Katrine Lundebye Helle Margrete Meltzer Judith Ann Narvhus Kristine Naterstad Ingolf Nes Bjørn Næss Jan Erik Paulsen Tore Sanner Janneche Utne Skåre Inger-Lise Steffensen Leif Sundheim Åshild KrogdahlAbstract
No abstract has been registered
Authors
Erlend Nybakk Eric N. HansenAbstract
No abstract has been registered
Authors
Kristoffer Segerholm Roger Rowell Pia Larsson-Brelid Magnus Wålinder Mats Westin Gry AlfredsenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Norwegian agriculture is totally dependent on a safe supply of seed of winter-hardy timothy varieties. The annual seed consumption varies depending on the extent of winter damages, particularly in northern Norway, and the average seed yield varies with weather and harvest conditions in the seed-producing districts in the southeastern and central part of the country. To buffer these variations, seed companies always keep stocks corresponding to 50-100 % of the average annual seed consumption. Such large stocks are risky to maintain as seed lots will loose germination over time. Our objective was to elucidate the effect of seed harvest time and seed storage location on the longevity of timothy seed. In 2003, timothy ‘Grindstad’ was combined directly on 2, 5 or 8 August corresponding to a seed moisture content (SMC) of 34, 27 and 20 %, respectively. After harvest the seed was dried to 10-11 % SMC. Germination analyses were accomplished 3, 15, 26 and 38 months after seed harvest; the three latter after splitting each seed lot into four sub-lots that were stored either in a conditioned seed store (4ºC, 30% RH), or in unconditioned warehouses at there climatically different locations. While seed harvest time had no effect on germination three months after harvest, differences became increasingly evident as time went by. After 38 months’ storage, seed stored in the conditioned store or in the warehouse at the continental location Tynset germinated, on average for harvest times, 15-16 units better than seed stored in the warehouse at the coastal location Vaksdal; and seed lots harvested at 20 % SMC germinated, on average for storage locations, 24 units better than seed harvested at 37 % SMC. While it has long been documented that direct combining at high SMC may damage seed germination, there has been less awareness that this damage may not manifest itself until after a certain storage period.
Abstract
No abstract has been registered
Authors
Gerhard Weiss Suzanne Martin Anne Matilainen Birger Vennesland Carmen Nastase Erlend Nybakk Laura BouriaudAbstract
This article examines innovation processes in forest recreational services on the basis of case studies in five European countries with differing institutional backgrounds of forest ownership and access rights. The analysis reveals that forest-related recreation services are developed under varying institutional conditions and on public as well as private land. Ideas for innovations in recreational services may come from within but often outside the forestry sector. Financing is provided from public and private sources. Both public and private spheres have important roles in providing natural, human and financial resources and usually a network of public and private actors are involved in innovation processes. Of particular importance are cross-sectoral interactions between forestry and tourism. Greater institutional support is needed for the development of forest-related recreation services because the field is at an early stage of development. It is concluded that support should focus on providing ideas and financial resources for product development and on facilitating cross-sectoral interaction between forestry and tourism actors. A particular need is seen for development of models for durable interaction between land owners and tourism operators on a regional scale.