Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2004
Sammendrag
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.
Sammendrag
Artikkelen drøfter saltinnhold i ulike bygningsdeler i Bryggen i Bergen, saltets opphav og betydning i forhold til bevaring av trevirket. Ulike nedbrytningsorganismer i saltholdig tømmer er også vurdert.
Sammendrag
The anatomical defense responses in stems of Norway spruce (Picea abies) clones of different resistance to pathogenic fungi were characterized over time and distance from small mechanical wounds or wounds inoculated with the root rot fungus Heterobasidion annosum. Common responses for both treatments included division of ray parenchyma and other cells in the cambial zone, accumulation of phenolic inclusions in ray parenchyma cells, activation of phloem parenchyma (PP) cells, and formation of traumatic resin ducts (TDs) in the xylem. TD formation occurred synchronously from a tangential layer of cells, or symplasmic domain, within the zone of xylem mother cells. TD induction is triggered by a signal, which propagates a developmental wave in the axial direction at about 2.5cm per day. TDs are formed at least 30cm above single inoculations within 16–36days after inoculation. The size and number of TDs is attenuated further away from the inoculation site, indicating a dose-dependent activity leading to TD development. Compared to sterile wounding, fungal inoculation gave rise to more and larger TDs in all clones, and multiple rows of TDs in weak clones. Fungal inoculation also induced the formation of more new PP cells, increasing the number of PP cells in the phloem in the year of inoculation up to 100%. TD and PP cell formation was greater in susceptible compared to resistant clones and after fungal versus sterile inoculation. Potential mechanisms responsible for this variable response are discussed.
Forfattere
Tor Håkon SivertsenSammendrag
In a small area of fruit production in southern Norway are placed four automated meteorological stations owned by The Norwegian Crop Research Institute. The measurements made at the stations are hourly recordings of precipitation, air temperature, leaf wetness and relative humidity of the air, plus some additional measurements of wind velocity, temperature of the soil and global radiation at two of the stations. The area has a relatively smooth topography with hills and no mountains. The highest point is located about 500 m above the sea level, and the lowest point is 16 m above sea level at the shores of the lake Norsjø, and most of the commercial orchards in the area are situated between 20 and 150 m above the sea level. The remote sensing research group at The Norwegian Meteorological Institute is providing hourly radar measurements of precipitation, from two different weather radars for this area (Gjertsen and Dahl, 2001). These measurements are collected each hour and stored in a systematic way in a database. One of the intentions of this project is to combine/compare measurements of meteorological parameters at the four automated stations with the weather radar measurements of precipitation. The precipitation data used is documented according to a system developed by The Norwegian Crop Research Institute. The representativeness of the different measurements of meteorological parameters is discussed and connected to a prediction model of apple scab infection, called modified Mills table (MacHardy and Gadoury, 1989, and Stensvand et. al, 1997) containing information on minimum air temperature and leaf wetness duration in specified periods. The original Mills table was published in 1944 ( Mills, 1944). A system for extrapolation, interpolation and combination of the relevant information mentioned is developed to get figures of temperature and leaf wetness duration to be put into the extended Mills table at all sites of this region. The usefulness of the system is to be tested and hopefully made partly operational in the growing season to come. The relevant information is communicated to the local private extension service. The intention of combining development, testing and operational use of a system is an important element of this project. References: Mills, W.D., 1944, Efficient use of sulfur dust and sprays during rain to control apple scab, Cornell Extension Bulletin, 630, 4 pp. MacHardy, W.E. & Gadoury, D.M., 1989: A revision of Mills" criteria for predicting apple scab infection periods, Phytopathology 76: 985-990 Stensvand, A, Gadoury, D.M., Amundsen, T., Semb, L., and Seem, R.C., 1997, Ascospore release and infection of apple leaves by conidia and ascospores of Ventura inaequalis at low temperatures, Phyopathology 87 : 1046-1053 Gjertsen, U. and Dahl, I., 2001, Development of a gauge adjustment method for correcting of radar precipitation estimates, Research report No. 128/2001, The Norwegian Meteorological Institute, Oslo, Norway
Forfattere
Klaus Mittenzwei Maria Loureiro Wenche Dramstad Wendy Fjellstad Ola Flaten Arnt Kristian Gjertsen Sjur Spildo PrestegardSammendrag
The level of support to Norwegian agriculture is partly justified with reference to agriculture’s multifunctionality. The concept of multifunctionality involves the provision of so-called “public goods» by agriculture, in addition to the production of food and fibre. Examples of these public goods include cultural landscape, biodiversity, ecological functions, cultural heritage, the viability of rural areas, and food security. The overall aim of the research project “Operationalization of multifunctionality using the CAPRI modeling system» is to study the effects of policy instruments on agriculture’s multifunctionality by defining quantitative indicators for selected elements of agriculture’s multifunctionality that can be implemented in the agricultural sector model CAPRI. This working paper takes a first step towards the appropriate regionalization when multifunctionality is concerned. The current regionalization of the CAPRI model is at the county level. This approach fails when multifunctionality is concerned, because many issues of multifunctionaliy (e.g., cultural landscape aspects) are independent of administrative borders at that level. As the aim of the overall project is to study the effects of policy instruments on agriculture’s multifunctionality, it is important to design regions within the CAPRI model that to a greater extent exhibit similar characteristics with respect to aspects of agriculture’s multifunctionality. Accordingly, it is reasonable to assume that policy changes will have quite similar effects on the multifunctionality indicators within each of these CAPRI regions. This task has been addressed by performing a cluster analysis by which Norwegian municipalities have been grouped with respect to their performance on variables that are expected to describe different aspects of the multifunctionality of agriculture. This information will then later on be used to regionalize the CAPRI model accordingly. […]
Sammendrag
Introduction: The objectives of the present study were to monitor H. annosum colonization rate (Hietala et al., 2003) and expression of host chitinases in clonal Norway spruce material with differing resistances. Transcript levels of three chitinases, representing classes I, II and IV, were monitored with real-time PCR.Material and MethodsInoculation experiment: Ramets of two 32 -year-old clones differing in resistance were employed as host material. Inoculation and wounding was performed. A rectangular strip containing phloem and cambium, with the inoculation site in the middle, was removed 3, 7 and 14 days after inoculation.Quantification of fungal colonizationMultiplex real-time PCR detection of host and pathogen DNA was performed (Hietala et al., 2003). Quantification of gene expression: Chitinase levels were monitored with Singleplex real-time PCR.Results and ConclusionsThe colonization profiles provided by the quantitative multiplex real-time PCR procedure (Hietala et al., 2003), when combined with spatial and temporal transcript profiling of 3 chitinases, provide a useful basis for identifying defense related genes, and for assessing their impact on pathogen colonization rates.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 (409) clone.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 signalperception.
Sammendrag
Mangelfulle renseløsninger for avløpsvann fra spredt bebyggelse er et forurensingsproblem i deler av Eidsvoll kommune. Enkelte av resipientene i området er meget belastet. Blant annet fører høye fosforutslipp til en økende algeoppblomstring. Spredt avløp representerer sannsynligvis en betydelig del av denne tilførselen. Kommunen har besluttet å foreta en beregning av forurensingstilførslene som grunnlag for å utrede alternative tiltak for å redusere forurensingen. I dette arbeidet har man benyttet GIS i avløp, som er en nedbørsfeltorientert avløpsmodell. Data til modellen er hentet fra kommunens anleggsdatabase, og utslipp av fosfor, nitrogen og organisk stoff er beregnet for 2187 avløpsanlegg. Utslippsmenger og miljøbelastning er deretter beregnet for hver resipient. Årlig tilførsel fra spredt avløp til alle resipienter er beregnet til ca 3.9 tonn fosfor, 25.8 tonn nitrogen og 47.8 tonn organisk stoff. Det er også beregnet miljøindeks for anleggene. Høy miljøbelastning tilsvarer høy indeksverdi. Beregningen viser at 79% av anleggene har høy eller meget høy miljøindeks. Den registrerbaserte metoden gir noe usikkerhet i beregningsgrunnlaget. Vi antar likevel at beregningene langt på vei gir et godt bilde av forurensnings-tilførslene i de enkelte delnedbørfelt. Ny utslippsberegning for de enkelte anlegg bør foretas når databasen er supplert med data fra feltkartlegging som kommunen nå er i gang med. Resultatene er lagret i GIS-database. Databasen danner grunnlag for kommunens videre oppfølging av anlegg, analyse av alternative tiltak samt produksjon av kart og rapporter. Den kan også kobles mot andre databaser i kommunen og danne grunnlag for innrapportering til sentrale myndigheter.
Sammendrag
More than 50% of the groundwater recharge in Norway takes place during snowmelt. Given the possible threat to groundwater quality caused by potentially rapid transport through the unsaturated zone, it is important to understand the infiltration processes that take place during snowmelt, and the factors that control the temporal and spatial variability of such processes. Here, we report on the results of an experimental study of infiltration during the snowmelt period of 2001. The study was carried out at a well-characterised field plot, close to Oslo Airport. In order to examine the spatial and temporal variability of snowmelt infiltration, a series of electrical resistivity surveys were carried out using electrodes installed below the ground surface and in shallow boreholes. The results from this time-lapse survey reveal significant changes over time, and suggest that localised infiltration takes place. The patterns of inferred increases in saturation are consistent with observed reductions in snow cover and appear to be principally controlled by variations in microtopography. Resistivity changes observed at depth, using the borehole-based electrodes, show rapid percolation through the unsaturated profile. Such behaviour is consistent with observed rapid changes in local groundwater levels. The results confirm the potential threat to groundwater quality during snowmelt and illustrate the spatial scale of processes that require adequate attention in groundwater management in vulnerable areas.
Forfattere
Lars NesheimSammendrag
Det er færre beitande husdyr i utmarka no enn tidlegare og det er ei av årsakene til den kraftige attgroinga mange stader. I tillegg til at kulturlandskapet vert mindre ope fører attgroinga til tap av biologisk mangfald. Sidan om lag 1990 har forskingsmiljøa vore opptatte av korleis beiting verkar på kulturlandskapet, og det er gjennomført fleire forskingsprogram i regi av Noregs forskingsråd der beiting har vore eitt av fleire forskingstema. Men det står mange utfordringar att, utfordringar som må møtast med tverrfagleg forsking, og ved at ein ser bruken av utmark og innmark i samanheng. Eit utval oppnemnt av Planteforsk, Institutt for husdyrfag NLH (IHF) og Norsk institutt for landbruksøkonomisk forskning (NILF) la i 2002 fram ei utgreiing om forskingsbehovet innan beiting med storfe og småfe på inn- og utmark (Nesheim et al. 2002). Det vart lagt mest vekt på fagområde, der Planteforsk, IHF og NILF anten er eller ønskjer å vere viktige aktørar. I dette innlegget er det gjort greie for bakgrunnen for forskingsbehovet og fire prioriterte forskingstema er presenterte.
Sammendrag
I år med tidlig setting, mye nedbør/vanning etter plastavtak og stor avling (sein høsting) får en størst utslag for delgjødsling. Bladgjødsling (med Stopit, Wuxal, Allgrow) kan gi betydelige avlingsutslag, og vi ubetinget være positivt. Dersom en skal ut i åkeren med tørråtesprøyting bør det drfor alltid tas med et bladgjødslingsmiddel, men det kan også tilrådes separate bladgjødsling-sprøytinger. Sortene reagerer forskjellig på delgjødsling og bladgjødsling, der Rutt gir bedre respons på dette enn t.d. Ostara. Det ser også ut itl at sortene reagerer forskjellig på delgjødsling/bladgjødsling med hensyn til tørrstoffinnhold. Rutt "tåler" dette bedre enn Ostara. Det blir atså viktig å kjenne de enkelte sortene sine behov/reaksjoner på de ulike innsatsfaktorene.