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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.

2008

Sammendrag

Increasing levels of Fusarium toxins, particularly deoxynivalenol (DON), T-2 /HT-2 and moniliformin, have been recorded in Norwegian cereals during the last few years. Previously F. avenaceum, F. culmorum, F. poae and F. tricinctum were the most common Fusarium species found on cereals in Norway. However, more recently F. graminearum has occurred more frequently, and the T-2/HT-2 toxin producing species F. langsethiae has also been detected, especially in oats. Investigations were made to clarify if there has been a change in the composition of Fusarium species. We are aiming to establish a three-step screening system in order to identify grain lots with high levels of Fusarium toxins: 1- Identify `high-risk" fields/lots, based on information on cultivation practice and climatic conditions, through the use of a FHB-prediction model. 2- Analyze the `high-risk" lots using a rapid test selected for its capacity to detect Fusarium toxins in a large number of grain samples at low cost. 3- Forward selected samples (based on analyses in step 2) for chemical mycotoxin analyses. Since 2004, we have run chemical mycotoxin analyses on grain samples from oat and spring wheat grown in Norway under different climatic conditions. Prediction models will be developed to estimate the risk of Fusarium infection and mycotoxin development in cereal fields, based on data for weather and cultivation practices. Preliminary results from using the prediction models will be presented.

Sammendrag

I to veksthusforsøk ble hvete og havre sprayinokulert under blomstring med en enkelt eller en blanding av flere Fusarium arter. De artene som ble studert var F. graminearum, F. culmorum, F. avenaceum, F. poae og F. langsethiae. Vi studerte i hvilken grad samspillet mellom artene påvirket etableringen og veksten av Fusarium, og også hvilken effekt dette hadde på mykotoksinproduksjonen.

Sammendrag

We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in spore development, pathogenicity and secondary metabolism. The FgStuA protein is a member of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and stuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity on wheat and colonization of apple slices. The mutant produces no detectable trichothecenes on the wheat cultivar Bobwhite, and

Sammendrag

We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in spore development, pathogenicity and secondary metabolism. The FgStuA protein is a member of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and stuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity on wheat and colonization of apple slices. The mutant produces no detectable trichothecenes on the wheat cultivar Bobwhite, and

Sammendrag

Increasing levels of Fusarium toxins, particularly deoxynivalenol (DON), T-2 /HT-2 and moniliformin, have been recorded in Norwegian cereals during the last few years. Previously F. avenaceum, F. culmorum, F. poae and F. tricinctum were the most common Fusarium species found on cereals in Norway. However, more recently F. graminearum has occurred more frequently, and the T-2/HT-2 toxin producing species F. langsethiae has also been detected, especially in oats. Investigations were made to clarify if there has been a change in the composition of Fusarium species. We are aiming to establish a three-step screening system in order to identify grain lots with high levels of Fusarium toxins: 1- Identify `high-risk" fields/lots, based on information on cultivation practice and climatic conditions, through the use of a FHB-prediction model. 2- Analyze the `high-risk" lots using a rapid test selected for its capacity to detect Fusarium toxins in a large number of grain samples at low cost. 3- Forward selected samples (based on analyses in step 2) for chemical mycotoxin analyses. Since 2004, we have run chemical mycotoxin analyses on grain samples from oat and spring wheat grown in Norway under different climatic conditions. Prediction models will be developed to estimate the risk of Fusarium infection and mycotoxin development in cereal fields, based on data for weather and cultivation practices. Preliminary results from using the prediction models will be presented.

Sammendrag

The Gram-positive plant pathogen Clavibacter michiganensis subsp. sepedonicus is the causal agent of potato ring rot, a wide-spread disease that causes huge economical losses. One strategy that may aid in gaining control of the disease is the development of agents that specificially inhibit growth of the pathogen. In this work, narrow-spectered antimicrobial substances that are secreted by the closely related tomato pathogen, Clavibacter michiganensis subsp. michiganensis, have been purified and studied. These antimicrobials exert growth inhibitory activity against Clavibacter michiganensis subsp. sepedonicus, and may become useful as control agents in the battle against the potato pathogen. The antimicrobial substances include a 14 kDa bacteriocin, a 2145 Da type B lantibiotic, and a series of non-proteinaceous antibiotics with molecular masses around 800-900 Da, putatively belonging to the tunicamycin family. The lantibiotic peptide, michiganin A, resembles actagardine, which is a type B lantibiotic produced by the actinomycete Actinoplanes liguriae. Both these peptides share traits with mersacidin, a well-known type B lantibiotic, including a conserved residue that is thought to be important for the antimicrobial activity of mersacidin.

Sammendrag

Rynkerose (Rosa rugosa) er en av de fremmede plantene som i dag sprer seg i sandstrender, sanddyner og tangvoller langs kysten, og som bidrar til å fortrenge de plantene som naturlig hører hjemme i slike områder. Flere verneområder har i dag også stor invasjon av rynkerose. Derfor ønsker forvaltningsmyndighetene nå å finne frem til prøve ut tiltak som kan utrydde den fra disse områdene. I Artsdatabanken sin Norske svarteliste fra 2007 var rynkerose en av de plantene som ble vurdert til å utgjøre en høy risiko for det biologiske mangfoldet som opprinnelig finnes på slike areal.

Sammendrag

Grassland legumes are essential in organic ruminant livestock production due to their ability to fix atmospheric nitrogen (N), providing high yields of high feeding value without N fertilization. White clover (Trifolium repens L.) and red clover (Trifolium pratense L.) are the most important legumes of temperate grasslands with white clover as the most widely used. New research has reviled new properties of red clover that may affect animal performance and product quality significantly. Red clover containing diets have increased the production of milk and meat (compared with grasses) and the content of beneficial fatty acids in milk and meat (compared with grasses and other legumes), improved the efficiency of feed N utilization (compared with Medicago sativa L.), and increased the milk content of isoflavones (compared with grass and white clover). Red clover contains high levels of the enzyme polyphenol oxidase that might reduce the extent of lipolysis and proteolysis. The paper presents a review on resent results from own and others" research on the use of red clover in the diet of ruminants and the likely mechanisms by which red clover affects production and product quality

Sammendrag

Endringane i plommene fram mot mogning i viktige faktorar som farge, fastleik og innhald av oppløyst turrstoff og syre, vart vist. Ved hausting må ein vurdera mogningsgraden ut frå farge og fastleik. For å vurdera mogningsgraden i "Edda" kan ein nytta fargekarta utarbeidde for søtkirsebær. I plommersortar der fruktene er delvis dekka av raud eller blå dekkfarge, kan grunnfargen vera ein god indikasjon for mogningsgrad. Grunnfargen må vera meir gul enn grøn. Fargekart utvikla for Tentation eple kan vera eit godt hjelpemiddel. For å øva seg i å vurdera høveleg fastleik, kan ein samanlikna med målingar av fastleik med DUROFEL. Det er viktig at mørk blå plommer (t.d. Jubileum") ikkje vert hausta før dei har byrja å mjukna. Grenseverdiar for fastleik og bilete av plommer med ulik mogningsgrad vart vist.