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.
2002
Authors
Arne Sandnes Halvor SolheimAbstract
Tree resistance to the patogenic blue stain fungus Ceratocystis polonica was studied in a monoclonal stand of Norway spruce (Picea abies [L] Karst.) in relation to tree social status and diameter at breast height (DBH). The DBH distribution of the 33-year-old stand ranged from 5 to 35 cm. There were clear differences in tree height between the suppressed (DBH 7.4-10.3 cm), co-dominant (DBH 11.8-17.4 cm) and dominant (DBH 18.6-23.9 cm) tree classes. The resistance was tested by mass inoculating trees with a low (400 inoculations m-2, 60 cm inoculation belt) or high (400 inoculations m-2, 120 cm inoculation belt) dosage. The small, suppressed trees were more susceptible to inoculation than the co-dominant and dominant trees, based on amount of blue-stained and occluded sapwood, lesion length, and dead cambium/phloem. A threshold in tree social status or tree size might be important in the overall resistance to fungal infection.
Authors
Grete Rasmussen Gunnar Fremmersvik Rolf Arnt OlsenAbstract
No abstract has been registered
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Authors
Wenche Dramstad Wendy Fjellstad Geir-Harald Strand Henrik Forsberg Mathiesen Gunnar Engan Jogeir N. StoklandAbstract
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Authors
Tore SkrøppaAbstract
No abstract has been registered
2001
Authors
John Beck Jensen J. Mölmann J. Olsen Lars Sandved Dalen Olavi Junttila Ö. Johnsen A. Lönneborg Carl Gunnar FossdalAbstract
No abstract has been registered
Authors
Lars Sandved DalenAbstract
No abstract has been registered
Abstract
To find interesting gene products and to study gene expression in the green parts of Norway spruce we have sequenced 1101 cDNA clones based on mRNA isolated from needles. Here we present some preliminary findings describing the frequency of different Expressed Sequence Tags (ESTs), the ratio of similarity to known and unknown sequences present in GenBank and sequences not previously reported from Norway spruce. In addition we have tried to place the ESTs into major categories based on putative function
Abstract
Adaptation to cold and freezing temperatures is crucial for survival in temperate and boreal areas. Compared with angiosperms, little is known about the mechanisms of freezing tolerance in gymnosperms. Coniferous species such as Norway spruce (Picea abies L. Karst.) have a wide distribution in boreal areas, indicating a strong ability to adapt to lasting periods of cold and freezing temperatures. Freezing-tolerant perennial plants survive subzero temperatures by forming ice in intercellular spaces and the xylem. Certain proteins associated with pathogen attack have been found to exhibit antifreeze activity, i.e. the ability to bind and modify the growth of ice. In order to study the possible role of pathogenesis-related proteins in development of freezing tolerance in Norway spruce, we looked at the accumulation of chitinases during hardening under both artificial and natural conditions. Our findings show that chitinases and other pathogenesis-related proteins, as well as antifreeze activity, are present in needles of Norway spruce, and that they increase in response to shorter daylengths and cold temperature. It is possible that pathogenesis-related proteins accumulated in conifers during cold acclimation could also exhibit antifreeze activity, and thus play an important role during development of freezing tolerance in perennial plants such as the gymnosperm Norway spruce.