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.
2007
Sammendrag
I to års forsøk med beising av settepoteter med ulik smittegrad av svartskurvsoppen har beising bare ført til litt raskere spiring, og ingen sikre effekter på avlingsmengden og tørrstoff. Settepoteter med lavt smittenivå av svartskurv spirte raskest. Mengsen svartskurv-sklerotier på knollene ble redusert ved beising, men frekvensen av knoller med svartskurv-sklerotier ble ikke redusert. Det ble ikke sikre forskjeller i virkningen av beisemidlene eller påføringsmetodene på avling eller kvalitet.
Forfattere
W.G Flier L.P.N.M Kroon Arne Hermansen H.M.G van Raaij B. Speiser L. Tamm J.G. Fuchs J. Lambion Jafar Razzaghian D. Andrivon S. Wilcockson C. LeifertSammendrag
Genetic variation and pathogenicity of Phytophthora infestans isolates collected from organic potato crops of the susceptible cv. Bintje and the moderately resistant cv. Santé were assesed in France, Norway, and the United Kingdom in 2001 and in Switzerland in 2001 and 2002. Population structures differed considerably between the four P. infestans populations. Those from France, Switzerland and the UK were mainly clonal populations showing restricted levels of genetic diversity, whilst those from Norway were mixed A1 and A2 mating type populations with high levels of genetic diversity, suggesting periodical sexual reproduction. Isolates collected from cv. Bintje were on average more aggressive than or comparable to isolates from cv. Santé. Race complexity varied considerably between the regional P. infestans populations with isolates from France and Switzerland showing the highest number of virulence factors. In all pathogen samples but the French, isolates collected from cv. Santé were more complex than isolates collected from cv. Bintje. No directional selection towards increased aggressiveness towards the more resistant cultivar Santé was observed. This suggests that there is no shift towards increased level of pathogenicity in P. infestans populations following the large-scale introduction of more resistant potato varieties in organic production systems in Europe.
Forfattere
Arne Stensvand Heidi Udnes Aamot Gunn Mari Strømeng Sonja Klemsdal Jorunn Børve Venche TalgøSammendrag
Foredrag om omfang og viktigheit Colletotrichum acutatum i norsk frukt- og bærdyrking
Sammendrag
Den middpatogene soppen Neozygites floridana er en viktig naturlig fiende for veksthusspinn - midden, Tetranychus urticae. Plantevernmidler, spesielt soppmidler, kan hemme denne nyttesoppen. Dette bør det tas hensyn til når en sprøyter mot soppsykdommer i jordbær og i andre kulturer hvor veksthusspinnmidden er et problematisk skadedyr.
Sammendrag
In Norway, Nordmann (Abies nordmanniana) and subalpine fir (A. lasiocarpa) are the dominant Christmas tree species and Noble fir (A. procera) the dominant species for bough production. In the spring of 2005 a survey was undertaken to determine the presence of fungi on seeds of these three plant species. Twelve seed samples were tested; five from Nordmann fir, four from subalpine fir and three from Noble fir. The test included seeds produced in Austria (Nordmann fir), Canada (subalpine fir), Georgia (Nordmann fir), Norway (Noble and subalpine fir) and Russia (Nordmann fir). The testing was done in a certified seed laboratory in Norway. One hundred seeds per sample were pre-treated in 1 % NaOCl and plated on potato dextrose agar (PDA), and 100 seeds per sample were pre-treated in H2O2 and plated on water agar (WA). The PDA Petri dishes were incubated for 5 to 7 days at 20 + 2 ºC and the WA Petri dishes for 15 to 19 days at 15 + 2 ºC, both under alternating 12 h NUV-light and 12 h darkness. To date not all of the fungi have been identified, but fungi from several genera have been found: Alternaria, Anthostomella, Aspergillus, Aureobasidium, Botrytis, Caloscypha, Cephalosporium, Chaetomium, Cladosporium, Dictyopolyschema, Epicoccum, Fusarium, Mucor, Penicillium, Phoma, Rhizopus, Trichoderma, and Trichothecium. Caloscypha was only found on one subalpine fir seedlot from Canada and Anthostomella on one subalpine fir seed from Norway. All the other fungi were more commonly found in all the samples. Fusarium species are well known to cause damping off in nurseries, but are not reported to cause problems in production fields. Species of Alternaria, Phoma, Botrytis and Trichothecium can damage seedlings. Anthostomella conorum is reported on cone scales of pine (Pinus spp.), but is not described as pathogenic. Aureobasidium is described as a saprophytic or weakly parasitic cosmopolitan fungal genus. Aureobasidium sp. is commonly found in Norway on buds of subalpine fir which fail to open in spring, and it will therefore be included in a pathogenicity test.
Sammendrag
A review on the most common potato-infecting viruses was given. The following viruses were described: Potato virus X, Potato virus Y, Potato virus M, Potato virus S, Potato moptop virus and Tobacco rattle virus. The way each virus is transmitted as well as strategies to prevent aphid transmission of viruses was explained
Sammendrag
Poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch), is a contemporary symbol of Christmas in most parts of the world. Today, Europe and North America represent the largest volume of production and sales, but demand is growing quickly in the other regions as poinsettia becomes more popular each year. In Norway, poinsettia is one of the most important pot plants, with a yearly production close to 6 million plants. Its ornamental value and innovation potential have laid the foundation for extensive research in Norway and elsewhere. Two viruses i.e. poinsettia mosaic virus (PnMV) and poinsettia cryptic virus (PnCV) can cause diseases in modern poinsettia cultivars. PnMV gives visible symptoms in poinsettia during parts of the growing season. Growers show great interest in the potential benefits of growing PnMV-free poinsettias. Traditionally, PnMV-free poinsettia plants were obtained by in vitro culture of apical meristems. However, this is a time-consuming method and the regenerated new PnMV-free poinsettia has sometimes lost the branching characteristic which is important for poinsettia. We have therefore developed an Agrobacterium-mediated transformation approach for poinsettia. Using this method, we have produced transgenic poinsettia with improved resistance against PnMV by expressing three hairpin (hp) RNA gene constructs which targeted various regions of the virus genome. Molecular analyses have confirmed the stable integration of transgenes into the poinsettia genome. This is the first report describing Agrobacterium-mediated transformation of poinsettia. The PnMV resistant transgenic poinsettia lines produced are of commercial potential. The methodology developed could also facilitate the further improvement of this ornamental plant with the aims of enhancing its disease resistance, quality traits, desirable colour and ornamental value. We have also transformed N. benthemiana to reveal the relationship of different vector constructs and the RNA silencing mediated PnMV resistance. This result will imrpove our understanding of RNA silencing mediated resistance through genetic engineering.
Forfattere
May Bente Brurberg Arne Hermansen Abdelhameed Elameen Vinh Hong Le Björn Andersson Asko Hannukkala Bent J Nielsen Jens G Hansen Jonathan YuenSammendrag
Studies of genetic variation of the late blight pathogen among isolates collected in 2003 in the Nordic countries were presented
Forfattere
May Bente Brurberg Arne Hermansen Abdelhameed Elameen Vinh Hong Le Björn Andersson Asko Hannukkala Bent Nielsen Jens G Hansen Jens G YuenSammendrag
Phytophthora infestans was isolated from potato leaves collected from 200 fields located in different parts of Finland, Denmark, Sweden and Norway in 2003. Sampling was carried out relatively late in the epidemic. The SSR analysis was carried out in Norway. Nine SSR markers were tested; Pi4B, Pi4G, PiG11, Pi02, Pi04, Pi16, Pi26, Pi33 and D13. Based on only 7 SSR markers 190 genotypes were found. Six genotypes occurred twice and one genotype occurred six times. The high genetic variation indicates sexual reproduction in the Nordic late blight population
Sammendrag
For at en fremmed art skal godkjennes til bruk i biologisk bekjempelse må det gjennomføres grundige studier av bl.a. utbredelse og etableringspotensial i Norge. Rovtegen Orius laevigatus, rovmidden Neoseiulus californicus og nyttenematoden Heterorhabditis bacterophora har vært brukt i biologisk bekjempelse før 2001, da den nye godkjenningsordningen for nytteorganismer ble innført. Artene ble imidlertid ikke godkjent ved vurderingen i 2001. Begrunnelsen var uklar systematikk, fare for genetiske innblandinger, og usikkerhet rundt naturlig utbredelse og etableringspotensial, og at artene ikke var påvist i Norge. Næringen ønsker å få de 3 artene tilbake på markedet. I 2007 gjennomførte vi derfor en kartlegging for å undersøke om O. laevigatus, N. californicus og H. bacteriophora har etablert seg i Norge. Det er samlet inn prøver både i områder der artene har vært brukt og i andre områder med mildt klima. Prøvene ble tatt i habitat som så langt det var mulig tilsvarer artenes habitat i det naturlige utbredelsesområdet. Det ble funnet 91 tegearter, men O. laevigatus ble ikke ble funnet. Det er funnet en del rovmidd, og nyttenematoder. Identifisering av artene vil bli gjort i februar 2008. Kuldetoleranseforsøk med 2 populasjoner fra hver av artene O. laevigatus og N. californicus er startet, og vil avsluttes i mai 2008.