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.
2010
Forfattere
Christer MagnussonSammendrag
The spread of the pinewood nematode (PWN) Bursaphelenchus xylophilus in Europe is a threat to 36 million ha Nordic coniferous forests. In spite of a strict phytosanitary regulation of wood imports, the volumes and an unclear distribution of PWN could result in an introduction into the Nordic region. In the present climate expression of pine wilt disease is expected only in hot summers. Hence, the detection of PWN in the Nordic area is likely to remain unnoticed for a considerable period of time. In Fennoscandia more than 9000 samples have been analyzed from risk areas and risk commodities. The focus often has been on the breeding substrate of the vector insects in the genus Monochamus. A recent study on a simulated introduction in Norway (Økland et al in print) indicates that 14 years may elapse before detection by the present level of 400 samples annually. It was demonstrated that an earlier detection of PWN provided by an annual sample volume of 10 000 samples would still not be sufficient for successful eradication of PWN by 3 km radius clear-cuts. So, large sampling volumes and strict import regulations for PWN are highly important for the Nordic area. Økland, B.O. Skarpaas, M. Schroeder, C. Magnusson, Å. Lindelöw & K. Thunes 2010. Is Eradication of the Pinewood Nematode (Bursaphelenchus xylophilus) Likely? An Evaluation of Current Contingency Plans. Risk Analysis in print Key Words: Pinewood nematode, Nordic area, sampling, eradication, regulation
Forfattere
Christer MagnussonSammendrag
S.radicicola is a parasite of barley and grasses like Poa annua and P.pratensis. The life cycle of a Norwegian population of S.radicicola (Poa-race) is studied in the laboratory by inoculating newly germinated P.annua (cv. Leif) with 140 juveniles from field collected galls and keeping the plants at 25˚C and 16 hrs light period. Juvenile stages are separated based on genital development. The first stage (J1) has 1 cell, while the following stages J2, J3 and J4 has 2, 3 and 4 (or more) cells in their genital primordia. J1 (L = 310-350μm) moults in the egg and J2 (L = 330-400μm) is the hatching stage. Nematodes emigrating from field collected galls were all J3:s (L = 360-430μm), and moulted outside the gall to J4 (L = 210-500μm). The first stage to appear in newly formed galls is large J4 (L=500-870 μm), which moults within 5 days to adult (L=820-1980 μm). Egg-laying starts within 13 days and eggs hatch after 22 days. Juvenile development in eggs starts at 5˚C, and 640 degree days are required for completing one generation corresponding to about 30 days at 25˚C. This means that in Norway S.radicicola may have up to 3 generations per year. The fact that J3 exit the galls and the large J4 is the first stage present in newly formed galls makes us speculate that the induction of gall formation occurs from outside by pre-infective J4, which later infects and develop inside the gall. Key Words: Root gall nematode, Subanguina radicicola, Poa annua, life cycle, Norway
Forfattere
Ingerd Skow HofgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Ingerd Skow HofgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Ingerd Skow HofgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Ingerd Skow HofgaardSammendrag
The increased occurrence of Fusarium toxins during recent years in Norwegian cereals, especially deoxynivalenol (DON) in spring wheat and DON and T-2/HT-2 toxins in oats (see abstract by Hofgaard et al), is a serious challenge for the cereal industry and farmers. Contamination levels above regulatory or advisory maximum limits have frequently been detected. In Norway, many farmers bring their grain directly to the buyer at harvest, and, in a time and cost perspective, it is not realistic to test all grain lots for mycotoxin content by chemical analysis. In order to reduce the risk of cereal grain lots with unacceptable Fusarium toxin content entering the feed and food chain, a three-step screening strategy has been developed in close cooperation with the cereal industry. 1 Toxin risk (DON, T-2/HT-2) in cereal fields will be predicted by models based on information on climatic conditions and agronomic/cultivation practice. 2 Grain from "high-risk" fields will be analysed for mycotoxins by a rapid "on-site" test method (lateral flow tests) before the grain enters the silo/storage/mill. 3 Samples from lots with toxin levels close to the defined maximum limits (based on analyses in step 2) can be forwarded to chemical analyses for precise decision of the mycotoxin concentrations.
Forfattere
Anne-Marte Tronsmo Ingerd Skow HofgaardSammendrag
The aim of the present project was to obtain better understanding of what is the source of primary inoculum for snow mould caused by M. nivale; to understand how inoculum of M. nivale survives from spring to fall, and from year to year, to understand how climatic conditions affects the potential inoculum by monitoring symptoms on plants, occurrence of the fungus and growth characteristics in vitro of strains sampled from snow melt and through summer and autumn. Snow mould symptoms and the occurrence of M. nivale in leaves and stems of grasses sampled from golf greens and foregreens was reduced during the growth season. M. nivale could also be isolated from locations without visible symptoms. Despite a lower isolation rate in autumn, M. nivale was again isolated in some of the originally locations the following spring. The M. nivale isolation rate was similar from sites located on greens compared to foregreens, and from greens located at more sunny sites compared to more shadowy located greens. We conclude that the fungus seem to survive from year to year within the same locations on greens and foregreens.
Sammendrag
I "Fusariumprosjektet" ved Bioforsk Plantehelse har vi i løpet av en 4 års periode (2006-2009) samlet inn kornprøver fra partier med norskprodusert havre og vårhvete med tilhørende opplysninger om klima og dyrkningsmessige forhold. Kornprøvene er videre analysert for innhold av 17 ulike mykotoksiner. Ved å sammenstille og analysere data og informasjon om de ulike kornprøvene, har vi kartlagt ulike faktorer som kan ha betydning for utvikling av mykotoksiner i kornet. Dataene er videre brukt for å utvikle varslingsmodeller for Fusarium-mykotoksiner i korn, og for utprøving av ulike hurtigmetoder som er utviklet for å måle innhold av mykotoksiner i korn.
Forfattere
Ingerd Skow Hofgaard Guro Brodal Heidi Udnes Aamot Oleif Elen Marika Jestoi Sonja KlemsdalSammendrag
In a 6-year period from 2004-2009, about 500 grain samples of spring wheat and oats were collected from farmers" fields in South East Norway. In order to study the effect of environmental factors on development of Fusarium spp. and mycotoxins in cereal grains, climate data was collected from the nearest weather station and information on cultivation practice in the respective fields was registered for each grain sample. All samples were analyzed for 18 different Fusarium-mycotoxins by LC-MS/MS at the Finnish Food Safety Authority, and the DNA content of selected Fusarium species (Fusarium graminearum, F. culmorum, F. avenaceum, F. poae, F. langsethiae/F. sporotrichoides) was determined by quantitative PCR.
Sammendrag
The increased occurrence of Fusarium toxins during recent years in Norwegian cereals, especially deoxynivalenol (DON) in spring wheat and DON and T-2/HT-2 toxins in oats (see abstract by Hofgaard et al), is a serious challenge for the cereal industry and farmers. Contamination levels above regulatory or advisory maximum limits have frequently been detected. In Norway, many farmers bring their grain directly to the buyer at harvest, and, in a time and cost perspective, it is not realistic to test all grain lots for mycotoxin content by chemical analysis. In order to reduce the risk of cereal grain lots with unacceptable Fusarium toxin content entering the feed and food chain, a three-step screening strategy has been developed in close cooperation with the cereal industry. 1 Toxin risk (DON, T-2/HT-2) in cereal fields will be predicted by models based on information on climatic conditions and agronomic/cultivation practice (see abstract by Elen et al). 2 Grain from "high-risk" fields will be analysed for mycotoxins by a rapid "on-site" test method (lateral flow tests) before the grain enters the silo/storage/mill. 3 Samples from lots with toxin levels close to the defined maximum limits (based on analyses in step 2) can be forwarded to chemical analyses for precise decision of the mycotoxin concentrations.