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.
2004
Abstract
We have monitored the H. annosum colonization rate and expression of host chitinases in Norway spruce material with differing resistances. Transcript levels of three chitinases, representing classes I, II and IV, were monitored with real-time PCR. Ramets of two 32 -year-old clones differing in resistance were employed as host material and inoculation and wounding was performed. Quantification of fungal colonization: Multiplex real-time PCR detection of host and pathogen DNA was performed. Chitinase transcript levels were also monitored with real-time PCR. Three days after inoculation, comparable colonization levels were observed in both clones in the area immediately adjacent to inoculation. Fourteen days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for the strong clone (589), but had progressed further into the host tissue in the weak clone (409). Transcript levels of the class II and IV chitinases increased following wounding or inoculation, while the transcript level of the class I chitinase declined following these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in 589 than in similar sites in 409 three days after inoculation, suggesting that the clones differ in the rate of chitinase-related signal perception. The spatiotemporal accumulation patterns obtained for the two clones used are consistent with their resistance classifications, these warranting further and more detailed studies on these chitinases.
2003
Abstract
Wintering ability in the field and resistance to different winter-stress factors under controlled environmental conditions were studied in a full-sib family of perennial ryegrass (Lolium perenne L.). Significant variation in tolerance to freezing and ice encasement, resistance to pink snow mould (Microdochium nivale) and also in winter survival and spring growth were found between the different genotypes. No strong correlations were found between the resistances to the different stress factors. These results indicate that resistance to different winter-stress factors is controlled by separate genes in perennial ryegrass. A low but significant positive correlation was found between spring growth of plants in the field after the first winter and both freezing tolerance and M. nivale resistance measured in controlled environments. Cold hardening seemed to influence freezing tolerance and M. nivale resistance differently in the different genotypes, since no distinct correlation in tolerance to freezing or resistance to M. nivale was found between unhardened and hardened plants. Tolerance or resistance to most of the winter stress factors measured was positively correlated with plant size.
Authors
Guro BrodalAbstract
No abstract has been registered
Abstract
Resultat frå forsøk med ulike dekkesystem for søtkirsebær sin effekt på mikroklima og fruktkvalitet er skildra i ein vitskapleg artikkel på engelsk. Resultata er delvis publisert på norsk i følgjande artikkel: Børve, J., A. Stensvand & M. Meland, 1997. Verknad av plastdekking på rotning hjå søtkirsebær. Informasjonsmøte i plantevern 1997 Grønn forskning 2/97. 252-255.
Abstract
A multiplex real-time PCR assay was developed to monitor the dynamics of the Picea abies-Heterobasidion annosum pathosystem. Tissue cultures and 32-year-old trees with low or high resistance to this pathogen were used as the host material. Probes and primers were based on a laccase gene for the pathogen and a polyubiquitin gene for the host.The real-time PCR procedure was compared to an ergosterol-based quantification method in a tissue culture experiment, and there was a strong correlation product moment correlation coefficient, 0.908) between the data sets. The multiplex real-time PCR procedure had higher resolution and sensitivity during the early stages of colonization and also could be used to monitor the host.In the tissue culture experiment, host DNA was degraded more rapidly in the clone with low resistance than in the clone with high resistance. In the field experiment, the lesions elicited were not strictly proportional to the area colonized by the pathogen.Fungal colonization was more restricted and localized in the lesion in the clone with high resistance, hereas in the clone with low resistance, the fungus could be detected until the visible end of the lesion. Thus, the real-time PCR assay gives better resolution than does the traditionally used lesion length measurement when screening host clones for resistance.
Abstract
Areas near the Norwegian-Russian border are being strongly contaminated by heavy metal emissions from copper-nickel smelters in the Kola peninsula. The present report presents data for the four elements arsenic, chromium, cobalt, and selenium in vegetation sampled in eastern Finmark, obtained by neutron activation analysis. It is no doubt that the smelters in Nikel and Zapolyarny, constitute the main source of these elements in this area. Some chromium comes from local domestic sources. Still, however, the concentration of these elements in soil and vegetation are probably too low as such to represent any harm to the ecosystem.
Authors
Halvor Solheim Kåre Olav VennAbstract
No abstract has been registered
Authors
Stephen Woodward Jan Stenlid Marco Michelozzi Halvor Solheim B. Karlsson Panaghiotis TsopelasAbstract
No abstract has been registered
Authors
Halvor SolheimAbstract
No abstract has been registered
Authors
M. Persson J. Lönnquist Bo Långström Halvor Solheim M. Kyto Anna-Karin Borg-KarlsonAbstract
No abstract has been registered