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.
2001
Authors
Malin Elfstrand Carl Gunnar Fossdal Gunilla Swedjemark David Clapham Olof Olsson Folke Sitbon Praveen Sharma Anders Lönneborg Sara von ArnoldAbstract
In this study we have investigated whether the defensin-like gene spi 1, isolated from Norway spruce, contributes to quantitative disease resistance and is a suitable candidate for utilisation in Norway spruce breeding programmes. The following questions have been raised: (1) Can the putative defense gene, spi 1, improve the defense towards microbial pathogens in a model plant species, tobacco? (2) Is it possible to produce transgenic plants of Norway spruce that overexpress spi 1 and are less susceptible to the pathogenic fungus Heterobasidion annosum? Compared to control plants, tobacco plants expressing spi 1 under an enhanced CaMV 35S promoter permitted less growth of the bacterial pathogen Erwinia carotovora. Embryogenic cultures of Norway spruce were transformed with a similar construct. The general phenotype of regenerated transgenic plants was normal, although it was difficult to maintain certain sublines in culture owing to poor initial growth. Among the transformed plants those with the highest content of SPI 1 displayed reduced fungal growth in the sapwood after inoculation with H. annosum. In conclusion, the spi 1 gene increases resistance in both homologous and heterologous systems.
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Authors
Mehreteab TesfaiAbstract
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Authors
Gunnar Ogner Guro Randem Torild WickstrømAbstract
Analyses of forest soils are widely used to monitor the effects of human activity on our environment. The overall quality of analytical data must, therefore, be sufficient to answer questions with regard to environmental changes taking place throughout several decades.Three horizons of an air-dried forest soil, was stored at 22 3 C, 3 C and 21 C for up to 1842 d to monitor its stability during storage. At room temperature, soil acidity increased and soil pH in water decreased by 0.1 to 0.3 pH units depending upon the soil horizon.The amount of C, P, and S extracted by 1M ammonium nitrate increased by 94%, 62% and 68%, respectively, after 1842 d. A corresponding increase in exchangeable cations [aluminium(Al), barium(Ba), calcium (Ca), magnesium (Mg), manganese (Mn), strontium (Sr), and zinc (Zn)] ranged from 11 to 23%. Storage at 3 C resulted in a decrease in pH only for mineral soil (10-15 cm layer). At 21 C, no changes in any of the soil-extractable components were found.
Authors
Jan Mulder Heleen A. de Wit Helena W.J. Boonen Lars R. BakkenAbstract
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Authors
I Szot Mekjell MelandAbstract
The cherry cultivars "Van", "Ulster" and "Burlat" grafted on the rootstocks seedling, `Colt" and `Gisela 5" were evaluated for important fruit quality parameters at Ullensvang Research Centre during the 1998 season. The largest fruit size was found on the cultivar/rootstock combinations `Van"/seedling, `Ulster/Colt" and `Burlat/Gisela 5". Other parameters like fruit firmness, stone weight, soluble solids, titratable acids and pH of the fruit juice were registered as well.
Authors
Dagang Tang Espen Lydersen H.M. Seip Valter Angell Odd Eilertsen Thorbjørn Larssen X Liu G. Kong Jan Mulder Arne Semb Svein Solberg K. Torseth Rolf D. Vogt Jinshong Xiao Dawei ZhaoAbstract
A 5-year Chinese-Norwegian research project was launched in the autumn of 1999. Forested sites for intensive studies are or will be established in the Chongqing municipality and in Guizhou, Hunan and Guangdong provinces in southern China. Previous studies have shown that harmful effects of acid deposition are likely to be most severe in this region. The research and monitoring sites shall give information about acidification mechanisms and effects on vegetation in order to improve policy oriented acidification models and critical load estimates as well as function as interdisciplinary training centers for acid rain research. Furthermore, the project shall improve the basis for developing an efficient regional acid rain monitoring system. At one site in Guizhou and one in Chongqing, research on soil and soilwater chemistry has been ongoing for several years. The forest at these sites appears to show symptoms of reduced vitality. The sensitivity of Chinese forests to acidification is uncertain and will be focused. Decision-makers should get an improved basis for optimal mitigation measures through the project.
Authors
Wenche E. Dramstad Gary L.A. Fry Wendy Fjellstad Birgitte Skar Wenche Helliksen May Liss Bøe Sollund Mari Sofie Tveit Anne Katrine Geelmuyden Erik FramstadAbstract
An accumulating body of research identifies the importance of landscape structure for a wide range of countryside interests. Landscape structure reflects the results of policies and practices, and is well-suited as a target for management actions. New landscape metrics represent a potential for indicator-based management, provided such metrics relate consistently to the landscape values of interest. In this paper we propose that aspects of landscape structure, specifically heterogeneity, may be related to landscape-based values such as biodiversity, cultural heritage and human appreciation. Birds and vascular plants correlated well with our index for the heterogeneity of land types, whereas insects did not. Occurrence of prehistoric graves was also associated with land type heterogeneity, though other types of cultural remains were not. Landscape experience seems to be associated with the heterogeneity of landscape space rather than heterogeneity of land types. Different aspects of heterogeneity, scale, and variation over time all contribute to explain how our measures of landscape-based values vary in their relationship to landscape heterogeneity. Successful integration between disciplines in landscape studies depends on having a common operational framework, a shared theoretical basis, and a harmonised approach to data collection.