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.
2005
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Fungi cause serious problems in wood utilization, and environmentally benign wood protection is required as an alternative to traditional chemicals. Chitosan has shown promising antimicrobial properties against several microorganisms. In this study, we present the characterization of and antifungal properties of a commercial chitosan formulation developed for impregnation of wood.A broad range of chemical and mycological methods were used to evaluate the uptake, fixation, and antifungal properties of chitosan for wood preservation. The results show that the higher the uptake of chitosan the lower the relative recovery of chitosan in wood after leaching, and the higher the molecular weight of chitosan the higher the recovery.Chitosan with high molecular weight proved to be more efficient against decay fungi than chitosan with low molecular weight. The fungi tested on chitosan-amended nutrient agar medium were totally inhibited at 1% (w/v) concentration.In decay studies using small wood blocks, 4.8% (w/v) chitosan concentration gave the best protection against brown rot fungi.
Sammendrag
During a period of 2 years and 3 months (1 January 2001 - 20 March 2003) Mycoteam had 3161 consultations in buildings in southern Norway, 1428 revealing damage from decay fungi. One consultation often revealed several occurrences of fungi, and the total number of occurrences of decay fungi was 3434. Thirty-five different species/genera/groups of decay fungi were recorded. During this period brown rot was more frequent (77.4 %) than soft rot (19.2 %) and white rot (3.4 %). Coniophora puteana (16.3 %) and Serpula lacrymans (16 %) were the most frequently identified species. Different species of the genus Antrodia were recorded in 18.4 % of the occurrences, while the group Corticiaceae accounted for 5.7 % and soft rot for 15.8 %. Investigations of damaged structural parts of buildings showed that decay fungi were most common in walls (18.3 %). Floor damage accounted for 13.4 % of the damaged structures and roofs for 8.8 %. Nearly all species and groups of the investigated fungi were most common indoors. Gloeophyllum sepiarium on the other hand was most common outdoors, and Dacrymyces stillatus was exclusively found outdoors. The Norwegian data were compared with published time series data from Denmark (1946-66, 1966-71, 1974-75, 1982) and Finland (1978-84, 1985-88). S. lacrymans and C. puteana were the most frequent species in these datasets too. Antrodia spp. were also common in the Finnish reports, but barely recorded (as identified species) in Denmark. In both the Danish and the Finnish data, damage to floors is the most frequently recorded structural damage in buildings.
Sammendrag
I et 4-årig prosjekt ("Økologisk produksjon av jordbær i Hedmark og Oppland") har det blant annet vært jobbet med alternative midler til bekjempelse av jordbærmjøldogg (Sphaerotheca macularis) og jordbærøyeflekk (Mycosphaerella fragariae) i frilandsjordbær. I det første året, 2001, ble det ikke registrert noen infeksjon av jordbærmjøldogg eller jordbærøyeflekk i feltet. I 2002 var det en liten, men signifikant (P = 0,04) reduksjon av mjøldogginfeksjon på blader behandlet med svovel. I 2003 reduserte behandling med svovel og bakepulver med rapsolje infeksjonen på bladene (P = 0,01), og på bær med henholdsvis 18,7 og 18,0 prosent (P = 0,1), når en sammenligner med kontrollen (sprøytet med vann). I 2004 reduserte alle alternative midler unntatt grønnsåpe, mjøldogginfeksjonen på blad (P = 0,004). Svovel og bakepulver med grønnsåpe ga størst reduksjon av mjøldogg på bær henholdsvis 15,1 og 13,9 prosent (P = 0,1) sammenlignet med kontrollen. I 2003 fikk planter behandlet med svovel og rapsolje med og uten bakepulver redusert infeksjon av jordbærøyeflekk (P = 0,005). I 2004 ga behandling med svovel signifikant reduksjon (P = 0,04) av infeksjon sammenlignet med kontrollen.
2004
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Light inhibits sporulation of Bremia lactucae, and is a component of models for lettuce downy mildew infection periods, but specific intensities and wavelengths involved are poorly understood. We evaluated environmental data and model performance in Norway for two systems, PlantPlus (PP) and Modell-Analys (MA), which are based on a model developed in California. Disease was detected following forecasts issued by both models in 5 of 8 fields. However, forecasted infection periods were not always followed by disease occurrence. Both PP and MA usually called for fewer fungicide applications than a calendar schedule of sprays at 10-day intervals, with no difference in disease suppression among treatments. Date of initial disease varied widely among sites, and may be related, in part, to light intensity and quality at Nordic latitudes, which differ substantially from those of California. Results of subsequent studies on light effects on B. lactucae will be reported.
Forfattere
Håvard Eikemo Sonja Klemsdal Ingvild Riisberg Peter Bonants Arne Stensvand Anne-Marte TronsmoSammendrag
Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia, and New Zealand, were identical in an analysis based on 96 polymorphic bands from seven primer combinations. Leather rot isolates of strawberry could not be distinguished from isolates from other hosts. The pathogenicity test of all 44 isolates on strawberry plants mostly gave unambiguous results, except for three American isolates, which seemed to have reduced aggressiveness compared to the crown rot isolates. These isolates also differed in the AFLP analysis. Comparing information on the origin of the isolates with results from the pathogenicity test, showed that isolates from strawberry fruits or petioles could be either leather rot or crown rot pathotypes. None of the isolates from hosts other than strawberry caused crown rot symptoms in strawberry.
Sammendrag
Indusert resistens er eit fenomen der plantene sine eigne forsvarsmekanismar vert aktivert ved hjelp av middel som ikkje har direkte effekt på skadegjeraren. Fordelen med bruk av slike middel er at skadegjeraren ikkje bygger opp resistens mot det, og det har effekt mot eit breitt spekter av sjukdomsframkallande organismar. Middel som induserer resistens har vist seg å ha like god effekt mot rotstokkròte og raud marg i jordbær som det mest brukte kjemiske middelet.
Forfattere
Nina Elisabeth Nagy Carl Gunnar Fossdal Paal Krokene Trygve Krekling Anders Lönneberg Anders Lønneborg Halvor SolheimSammendrag
Polyphenolic parenchyma cells (PP cells) in Norway spruce (Picea abies (L.) Karst.) stem phloem play important roles in constitutive and inducible defenses. To determine whether anatomical and molecular changes in PP cells are correlated with tree resistance, we infected two Norway spruce clones with the pathogenic fungus Ceratocystis polonica (Siem.) C. Moreau. The fungus induced significantly different lesion lengths in the two clones, indicating that one clone was more resistant to the fungus (short lesions) than the other (long lesions). After infection, the cross-sectional area of PP cells and their vacuolar polyphenol bodies increased in the three most recent annual rings of PP cells in both clones. The more resistant clone had larger PP cells with denser polyphenol bodies than the less resistant clone, whereas the less resistant clone accumulated relatively more polyphenols after infection. Compared with the less resistant clone, the more resistant clone contained higher starch concentrations before infection that were reduced more quickly after infection before returning to original values. Low transcript levels of chalcone synthase were detected in uninfected tissues of both clones, but the levels increased dramatically after infection. Transcript levels were higher and peaked 6 days earlier in the more resistant clone than in the less resistant clone. The activity of at least one highly basic peroxidase isoform was greatly enhanced after infection, and this increase occurred earlier in the more resistant clone.
Sammendrag
Short description of fungal pathogens found on plum fruits in Norway.