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.
2009
Forfattere
Trond Hofsvang Brita ToppeSammendrag
Det er ikke registrert sammendrag
Forfattere
Agnethe ChristiansenSammendrag
Det er ikke registrert sammendrag
Forfattere
May-Guri Saethre Arnstein Staverløkk Trond HofsvangSammendrag
The history of Harmonia axyridis and a summary of surveillance & research in Norway till June 2009 are given. H. axyridis was assessed as a potential bio-control agent for use in Norwegian greenhouses in 2001. The risk of establishment outdoors was assessed too high and no permission was given. The first record in Norway was in 2006 when one adult was found on Thuja sp. imported from the Netherlands. In late 2007 and throughout 2008 adults were found indoors/outdoors at several locations in the Oslo-area. Establishment outdoors became evident. Observations in Aust-Agder and Vestfold revealed further spread/introduction to new areas. The bioclimatic potential of H. axyridis was assessed in 2007 by the aid of CLIMEX and national agrometeorological data, showed that suboptimal microclimates for the species can be found in the coastal areas of the south. In late 2008 a web-site was launched aiming to engage the public to submit observations on-line and has contributed to monitor development of the species across the country. Competition experiments with H. axyridis and Coccinella septempunctata in 2008/2009 showed that only H. axyridis eggs & larvae survived when the two species were mixed.
Forfattere
Carl Gunnar Fossdal Nadeem Yaqoob Halvor SolheimSammendrag
The root-rot causing fungus Heterobasidion annosum senso lato is the most devastating pathogen of conifers in Europe. This pathogen enter Norway spruce trees trough the roots and colonizes the tree from within, growing as a saprophyte when established within the dead heartwood and acting as a necrotroph when in contact with living host tissue. The genome of this devastating pathogen has now been sequenced in collaboration with JGI and gene annotation is ongoing and genomic work is currently in progress (Stenlid et al. work in progress). We have worked with the host Norway spruce from a molecular perspective for more than ten years. Twenty percent of the trees in Norwegian spruce stands tend to be infected and this pathogen that can colonize ten meters up inside the trunk. The tree have defences against this pathogen and the attack can be fought off by the bark and living wood but not by the hearthwood. The tree has a unique defense against this internal attack by forming a reaction zone; in this case the host defense is directed inwardly by the still living sapwood toward the central colonized wood. We have in the last years studied the host responses to infection in Norway spruce clones at the transcriptional level and found that the speed of recognition and spatial defense signalling appears to be the hallmarks of trees with high degree of resistance. We strive to study both partners in this pathosystem from a molecular perspective, and are using suppressive subtractive hybridization (SSH) followed by Real-Time RT PCR verification to look at differentially expressed genes(Yakovlev et al. 2008). In addition the colonization profiles are followed on extracted gDNA using quantitative Real-Time PCR (Hietala et al. 2009).
Forfattere
Nadeem Yaqoob Jan Karlsson Benedicte Riber Albrectsen Halvor Solheim Carl Gunnar FossdalSammendrag
In natural conditions plants are continuously exposed to number of pathogens both biotrophs and necrotrophs. To understand their defense response at the transcript level two clones C72 and C23 with differential level of resistance from the SwAsp collection were inoculated with a biotroph (Melampsora magnusiana Wagnar) and necrotroph (Ceratocysis spp.) and compared to wounded and healthy controls. Samples were collected in leaves and areas some distance away from the inoculation site to examine the long distance (systemic) defense responses at day, day3 and day14 post treatments. We performed microarray experiments on the necrotrophic and biothrophic interaction compared with the healthy controls and found that the two clones respond in widely different fashions to the treatments applied. Clone C23 showed almost no response to biotroph and necrotroph inoculations after 24 hours while clone 72 gave a clear defense response to both pathogens. We are now in the process of verifying these results and looking at additional time-points using qRT-PCR.
Forfattere
Helge SjursenSammendrag
Plantearter som vi i dag kaller "ugras", utgjør en viktig del av Norges og Skandinavias vegetasjonshistorie etter siste istid. Da det første primitive åkerbruket begynte, fikk vi videre spredning av arter som allerede var kommet, og nye arter som mennesket brakte med seg, mer eller mindre frivillig. Gjennom lange tider har mennesket "formet" floraen, båe ved dyrkingen av jorden og ulik bruk. Invaderende fremmede planter er et relativ nytt begrep, men vi har alltid hatt slike arter.
Forfattere
Trond RafossSammendrag
Jordtemperatur brukes flittig av agronomer for å bestemme når det er på tide å sette i gang tiltak i våronna. Når jordtemperaturen stiger over 5 ºC om våren regnes vekstsesongen for å være i gang. Klimatologer bruker derimot kriterier basert på temperaturen i lufta til å beregne tidspunkt for vekstsesongens start, slutt og lengde. Stemmer klimatologen og agronomens tilnærminger overens?Kan jordtemperaturer tilføre oss kunnskap om klimaendringer utover luftas temperatur?
Forfattere
Unni Abrahamsen Ragnhild Nærstad Andrew Dobson Arne Hermansen Arne Stensvand Berit Nordskog Brita Toppe Guro Brodal Jorunn Børve Oleif Elen Venche Talgø Agnethe ChristiansenSammendrag
Middelprøvingsrapport for soppmidler 2009
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Two mature clones of Norway spruce (Picea abies (L.) Karst.) shown to have different level of resistance towards inoculation of Heterobasidion parviporum were compared with respect to spatiotemporal expression of transcripts related to biosynthesis of lignin, stilbenes and other phenolic compounds in response to fungal inoculation and physical wounding. Both clones responded to H. parviporum and physical wounding at transcriptional and chemical levels. Taxifolin, detected in the resistant clone only, increased in concentration following both wounding and inoculation. Concentrations of stilbenoid glucosides were highest in the susceptible clone. Following wounding or inoculation, concentrations of these glucosides increased in the susceptible clone, and quantities of their corresponding aglycones increased dramatically in both clones close to the treatment point. Significant changes in transcription were detected over the entire lesion length for all transcripts, and only the changes in a few transcripts indicated a response to inoculation with H. parviporum differing from that caused by wounding alone. The resistant clone had higher basal concentrations of lignin (LTGA) compared to the susceptible clone; concentrations increased in both clones after wounding and wounding plus inoculation treatments, but remained consistently higher in the resistant clone, suggesting higher lignin levels in the cell walls compared to the susceptible clone. In addition, the transcript level in the same clones was also measured the following year and we saw indications of primed defences for a number of gene products likely resulting from the inoculations performed 12 months prior.