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.
2006
Forfattere
Trygve S. Aamlid Jon Atle RepstadSammendrag
Etter søknad fra Felleskjøpet Øst Vest, Strand Brænderi AS, Felleskjøpet Rogaland Agder, Felleskjøpet Trondheim og Kimen Såvarelaboratoriet AS har Norges forskingsråd innvilget det fireårige prosjektet "SAFESEED". " SAFE supply of climatially adapted forage SEED through reduced storage losses". Målet med prosjektet er å redusere lagringstapet av norske frøpartier. Forsknings- og utviklingsarbeidet vil ble utført som et samarbeid mellom frøforretningene, Kimen Såvarelaboriet og Bioforsk Øst Landvik. Lagringsforsholda på de kommersielle frølagerne skal undersøkese, og det skal utarbeides spirekrafttester for å forutsi lagringsevnen til ulike frøpartier.
Forfattere
Liv Solemdal Liv Birkeland (sluttet)Sammendrag
Regjeringas mål for økologisk mat. Eksempler fra samarbeid med kjøkkenet på St Olavs Hospital og økologiske produsenter i Midt-Norge.
Sammendrag
Lærebøker av Landbruksuniversitetet i Wroclaw
Sammendrag
The common way to obtain yield maps today, is to use combined harvesters equipped with GPS and some kind of monitor, which measures the cereal flow through the elevator. This method is known to have many error sources, and the raw data is commonly filtered to reduce the error. An alternative method would be to carry out non-destructive yield measurements on the crop before harvesting. Reflection measurements by means of radiometric spectrometers provide such an alternative. In this study we tested how a multi-spectral hand held spectrometer (CropScan), a hyper-spectral airborne sensor (ASI) and satellite images from the multi-spectral satellite Landsat 7 could be used to estimate cereal yields in plot trials, and on farm scale. In spite of the relatively low spatial resolution (30 m) of the satellite images, almost 60 % of the yield variation in winter wheat could be predicted at the farm scale using the satellite data. The prediction accuracy could be increased to about 80 % using the handheld and the airborne equipment to estimate yields in plot trials.
Forfattere
Ingvild Wartiainen Anne Grethe Hestnes Ian R. McDonald Mette M. SvenningSammendrag
A Gram-negative, rod-shaped, non-motile, non-spore forming bacterium (SV96T) was isolated from wetland soil near Ny-Ålesund, Svalbard. On the basis of 16S rRNA gene sequence similarity, strain SV96T was shown to belong to the Gammaproteobacteria, related to Methylobacter psychrophilus Z-0021T (99.1 %), Methylobacter luteus ATCC 49878T (97.3 %), Methylobacter marinus A45T (97.0 %) and Methylobacter whittenburyi ATCC 51738T (95.8 %); the closest related species within the genus Methylomicrobium with a validly published name was Methylomicrobium album ATCC 33003T (95.0 %). Chemotaxonomic data (including the major fatty acids: 16 : 1v8, 16:1v7 and 16:1v5t) supported the af"liation of strain SV96T to the genus Methylobacter. The results of DNA"DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV96T from the four Methylobacter species mentioned above. Strain SV96T therefore represents a novel species, for which the name Methylobacter tundripaludum sp. nov. is proposed (type strain SV96T =DSM 17260T = ATCC BAA-1195T).
Forfattere
Ingvild Wartiainen Anne Grethe Hestnes Ian R. McDonald Mette M. SvenningSammendrag
A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Ålesund, Svalbard Islands, Norway (78° N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBPT (97.2 %) and Methylocystis echinoides IMET 10491T (97 %). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0 % similarity). Chemotaxonomic and phenotypic data (C18 : 1w8 as the major fatty acid, non-motile, no rosette formation) supported the af"liation of strain SV97T to the genus Methylocystis. The results of DNA"DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97T from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (=DSM 17261T =ATCC BAA-1196T).
Forfattere
Anne S. HalstensenSammendrag
This study is the first to apply real-time PCR on personal samples of inhalable grain dust for the quantification of tri5 and species-specific Fusarium-DNA, which may have potential for risk assessments of inhaled trichothecenes.
Forfattere
Hege Hvattum Divon Carmit Ziv Olga Davydov Oded Yarden Robert Fluhr Hege DivonSammendrag
Fusarium oxysporum is a soil-borne pathogen that infects plants through the roots and uses the vascular system for host ingress. Specialized for this route of infection, F. oxysporum is able to adapt to the scarce nutrient environment in the xylem vessels. Here we report the cloning of the F. oxysporum global nitrogen regulator, Fnr1, and show that it is one of the determinants for fungal fitness during in planta growth. The Fnr1 gene has a single conserved GATA-type zinc finger domain and is 96% and 48% identical to AREA-GF from Gibberella fujikuroi, and NIT2 from Neurospora crassa, respectively. Fnr1 cDNA, expressed under a constitutive promoter, was able to complement functionally an N. crassa nit-2(RIP) mutant, restoring the ability of the mutant to utilize nitrate. Fnr1 disruption mutants showed high tolerance to chlorate and reduced ability to utilize several secondary nitrogen sources such as amino acids, hypoxanthine and uric acid, whereas growth on favourable nitrogen sources was not affected. Fnr1 disruption also abolished in vitro expression of nutrition genes, normally induced during the early phase of infection. In an infection assay on tomato seedlings, infection rate of disruption mutants was significantly delayed in comparison with the parental strain. Our results indicate that FNR1 mediates adaptation to nitrogen-poor conditions in planta through the regulation of secondary nitrogen acquisition, and as such acts as a determinant for fungal fitness during infection.
Forfattere
Anne S. Halstensen Karl-Christian Nordby Sonja Klemsdal Oleif Elen Per Erik Clasen Weijnand EduardSammendrag
Trichothecenes are immunosuppressive mycotoxins produced mainly by Fusarium spp. and often are detected as natural contaminants of grain and other agricultural products. Exposure to trichothecenes through inhalation during grain work may represent possible health risks for grain farmers. We aimed, therefore, to investigate the level of Fusarium spp. and trichothecenes in settled grain dust collected during work on 92 Norwegian farms. Mycotoxins were determined by gas chromatography-mass spectrometry, whereas the Fusarium spp. were identified and quantified both by species-specific semiquantitative polymerase chain reaction (PCR) and by cultivation. All potential trichothecene-producing molds in the grain dust were quantified using a PCR assay specific for tri5, the gene coding for trichodiene synthase that catalyzes the first step in the trichothecene biosynthesis. We performed correlation analysis between mold-DNA and mycotoxins to assess whether the PCR-detected DNA could be used as indicators of the mycotoxins. The methodological problem of detecting small amounts of airborne mycotoxins during grain work may then be avoided. Whereas the trichothecene-producing Fusarium species in grain dust could not be identified or quantified to a sufficient extent by cultivation, all investigated Fusarium spp. could be specifically detected by PCR and quantified from the DNA agarose gel band intensities. Furthermore, we observed a strong correlation between the trichothecenes HT-2 toxin (HT-2) or T-2 toxin (T-2) and DNA specific for tri5 (r = 0.68 for HT-2 and r = 0.50 for T-2; p < 0.001), F. langsethiae (r = 0.77 for HT-2 and r = 0.59 for T-2; p < 0.001), or F. poae (r = 0.41 for HT-2 and r = 0.35 for T-2; p < 0.001). However, only a moderate correlation was observed between the trichothecene deoxynivalenol ( DON) and the combination of its producers, F. culmorum and F. graminearum (r = 0.24, p = 0.02), and no significant correlation was observed between DON and tri5. PCR clearly improved the detection of toxigenic Fusaria as potential sources of health risks for farmers inhaling grain dust during work, but the use of Fusarium-DNA as indicators for trichothecenes should be used cautiously.
Forfattere
Erik LysøeSammendrag
Flere av de soppartene som naturlig finnes i korn, kan produsere giftstoffer. Det er et mål å redusere mengden av slike sopptoksiner til et nivå som gjør at vi trygt kan benytte kornet som råstoff for produksjon av mat eller dyrefòr. Den viktigste kilden til mykotoksiner ute på kornåkeren er Fusarium. Ulike Fusarium-arter kan produsere flere forskjellige mykotoksiner. Kunnskap om hvordan denne produksjonen skjer kan bidra til å redusere dette problemet.Ved å studere prosesser i Fusarium-sopper som produserer store mengder av soppgiften zearalenon, har de klart å frambringe viktig kunnskap om hvordan denne soppgiften dannes i soppen. Zearalanon er en østrogenlignende forbindelse som virker som en hormonhermer i mennesker og dyr, og er et av de vanligste mykotoksinene man finner i korn. Flere soppgener som var mye mer aktive når zearalenon ble produsert enn når denne forbindelsen ikke ble laget, ble funnet og karakterisert. Det ble laget en Fusarium-mutant der ett av soppgenene, PKS4, var inaktivert. Denne mutanten hadde mistet sin evne til å produsere zearalenon. På denne måten kunne man sikkert identifisere ett av flere gener som var absolutt nødvendig for at Fusarium skulle kunne lage dette toksinet. Genet PKS4 kodet for en polyketidsyntase, og hvordan aktiviteten av dette og andre gener ble regulert når zearalenon ble laget, ble studert i mer detalj. Aktiviteten av de samme genene ble også studert i unge hvete- og havrekorn som var smittet med Fusarium. Zearalenon sin rolle i soppen var tidligere ukjent, men basert på resultater framkommet i dette arbeidet er man ett skritt nærmere en forståelse av denne prosessen.