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.
2008
Abstract
No abstract has been registered
Abstract
The difficulty in subculturing biotrophic fungi complicates etiological studies related to the associated plant diseases. By employing internal transcribed spacer rDNA-targeted quantitative real-time polymerase chain reaction, we now show that the heteroecious rust Thekopsora areolata, commonly associated in natural conditions to sapling shoots and cones of Norway spruce and leaves of wild bird cherry, frequently infects nurserygrown seedlings of the conifer. A spatial sampling scheme was used to investigate seedlings and saplings of Norway spruce showing phloem necrosis: the highest concentration of DNA of T. areolata was recorded in the area with necrotic phloem. The separate analysis of bark and wood tissues suggested that the initial spread of the rust to healthy tissues neighboring the infection site takes place in the bark. A Phomopsis species found to coexist with T. areolata in several seedlings showed very high DNA levels in the upper part of the lesion, and even in the visually healthy proximal tissues above the lesions, which indicates that the ascomycete, most probably a secondary invader following primary infection by T. areolata, has a latent stage during early host colonization. We hypothesize that this hemibiotrophic mode of infection contributes to the successful coexistence of Phomopsis with a biotrophic rust.
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No abstract has been registered
Abstract
Many bacteria produce antimicrobial substances such as nonribosomally synthesized antibiotics and ribosomally synthesized proteinaceous compounds referred to as bacteriocins. Secretion of antimicrobials is generally thought to contribute to the competitiveness of the producing organism, but there are indications that these compounds in some cases may have regulatory roles too. Bacteriocins most often act on closely related species only and are thus of interest for application as targeted narrow-spectrum antimicrobials with few side effects. Although the application of bacteriocins in plant disease control is an attractive option, very little is known about the occurrence and roles of these compounds in plant pathogenic bacteria and their natural competitors occurring in the same biotopes. This study presents an overview of current knowledge of bacteriocins from plant pathogenic bacteria.
Abstract
Rural communities in Norway have been under great economic stress in recent years. There has been an increasing debate about how to utilize the large potential in a growing tourism industry to promote rural employment and income. This study is based on the institutional view of innovation with a focus on institutions that are important for stimulating innovations. The objectives are: 1) to determine if networking is positively related to innovativeness and if innovativeness is positively related to performance in the nature-based tourism industry in Norway and 2) to develop an in-depth understanding of how different actors trigger a member of the industry to change, create, or otherwise innovate. An e-mail survey was conducted of companies across the country followed by a qualitative study in one Norwegian municipality. Results indicate that there is a positive connection between networking and innovativeness, and between innovativeness and performance. A qualitative case example illustrates the interaction among actors and the resulting impacts on the innovation process.
Authors
Stig Morten Thorsen Lars Egil Haugen Mats HöglindAbstract
No abstract has been registered
Authors
Trond Rafoss Arild Sletten Leif SundheimAbstract
No abstract has been registered
Abstract
No abstract has been registered
2007
Authors
Gunnhild JaastadAbstract
Abstract: Black cherry aphid [ Myzus cerasi (Fabricius)] and cherry fruit moth [ Argyresthia pruniella (Clerck)] are the main insect pests on sweet cherries in Norway. In this study, application of rapeseed oil alone and rapeseed oil mixed with pesticides were tested as a control method against overwintering eggs of both black cherry aphid and cherry fruit moth. Results showed that rapeseed oil applied at the late dormant stage significantly reduced damage by black cherry aphid. Efficiency of oil mixed with pesticides was higher, but only significant in three of seven trials. The efficiency of rapeseed oil against cherry fruit moth was low compared with what was achieved for black cherry aphid, but within the range that has been reported for other botanical pesticides. As for the black cherry aphid, adding pesticides to oil decreased damage by the cherry fruit moth. Timing of treatment and effect of temperature were discussed.
Authors
Klaus Mittenzwei Wendy Fjellstad Wenche Dramstad Ola Flaten Arnt Kristian Gjertsen Maria L. Loureiro Sjur Spildo PrestegardAbstract
No abstract has been registered