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.
2006
Abstract
Based on field observations of leaf morphology and variation in chloroplast DNA (cpDNA) in Scandinavia, Norway has been suggested as a suture zone for elm (Ulmus glabra) from different glacial refugia. The aim of this paper was to study the geographical concordance between the maternally inherited cpDNA markers (16 populations) and the assumed polygenic and biparentally inherited leaf traits, studied in a field trial (five populations).Two cpDNA haplotypes were detected, but without geographical structure. Leaf traits showed a gradient from typical ssp. montana traits (relatively long, long tapering, absent acute lobes) in western populations to more ssp. glabra-like traits (relatively broad, short tapering, acute lobes present) in eastern and northern populations.The overall geographical concordance between haplotype distribution and leaf traits was limited, probably owing to different inheritance of cpDNA and leaf traits, but the spatial variation in leaf traits and cpDNA in a subset of common populations (n=5) was compatible with a dual migration of elm to Scandinavia. Both measures suggest a broad suture zone, covering the entire distribution of elm in Norway.The results are discussed in relation to the use of maternally inherited markers, such as cpDNA, in delimiting suture zones.
Authors
Anders BrynAbstract
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Authors
Talis GaitnieksAbstract
Normally, infection by Heterobasidion annosum does not affect the fine roots of Norway spruce. Thus, mycorrhizas may be found with rot-affected conifers. The objective of the given study was to compare the morphological indices and mycorrhization of fine roots for rot-infected and healthy Norway spruce trees. The root samples were collected on 14 plots. In 6 of the plots H. annsoum was established. The plots were either on mineral soils or peaty soils. The major morphological indices of fine roots (such as root length, volume, number of root tips) were found to be substantially higher (=0,05) for the plots with only healthy Norway spruce trees. Twisted, irregularly thickened mycorrhizas of bunch-like distribution were dominant for the plots with H. annosum infected Norway spruce trees.
Abstract
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Authors
Adam ParuchAbstract
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Authors
Halvor SolheimAbstract
Norway spruce suffers from serious root and butt rot problems from sea level up to the timber line in Norway. In this paper the most common fungi causing white rot is presented with special notes on gross characteristics of the rot. During the meeting we visited a stand near the timberline where logging was ongoing. Isolations were done from nearly hundred rotten logs and the results are presented.
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No abstract has been registered
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No abstract has been registered
2005
Abstract
*Strawberry Fragaria × ananassa (cv. Korona) was inoculated with Botrytis cinerea by dipping berries in a conidial suspension. *Colonization by the pathogen was monitored using real-time PCR, ELISA and ergosterol assays, the first showing the highest sensitivity. The expression of pathogen B-tubulin and six polygalacturonases (Bcpg1-6) and three host defence genes (polygalacturonase-inhibiting protein (FaPGIP) and two class II chitinases) were monitored using real-time RT-PCR. *The maximum transcript levels of the host defence genes occurred at 16 h postinoculation (hpi) at the presumed initial penetration stage. The unique transcript profile of Bcpg2 over the 96-h incubation time and its high transcript levels relative to those of the other Bcpgs at 8-24 hpi suggest that the gene has a specific role in the penetration stage. *Bcpg1 was expressed constitutively at a relatively high level in actively growing mycelia throughout the experimental period. Comparison of the transcript profiles indicated that Bcpg1 and Bcpg3-6 were coordinately regulated.
Authors
Lisbeth Mehli Trygve D. Kjellsen Frances M. Dewey Ari M. HietalaAbstract
Strawberry Fragariax ananassa (cv. Korona) was inoculated with Botrytis cinerea by dipping berries in a conidial suspension. The colonization of the pathogen was monitored with real-time PCR, ELISA and ergosterol assays, the first showing the highest sensitivity. The expression of pathogen -tubulin and six polygalacturonases (Bcpg1-6) and three host defense genes (polygalacturonase inhibiting protein (FaPGIP) and two class II chitinases) were monitored with real-time RT-PCR. The maximum transcript levels of the host defense genes occurred at 16 hours post inoculation (hpi), at the presumed initial penetration stage.The unique transcript profile of Bcpg2 over the 96-hour-long incubation time and its high transcript levels relative to those of the other Bcpgs at 8 to 24 hpi suggest that the gene has a specific role in the penetration stage.Bcpg1 was constitutively expressed at a relatively high level in actively growing mycelia throughout the experimental period. Comparison of the transcript profiles indicated that Bcpg1 and Bcpg3-6 were co-ordinately regulated.