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
Forfattere
Tao Zhao Anna-Karin Borg-Karlson Bo Långström Halvor Solheim Erik ChristiansenSammendrag
Induced reactions in the phloem is a basic mechanism of conifer resistance to bark beetle and their associated fungi (1,2). Previous research has proved that certain doses of Ceratocystis polonica infection or methyl jasmonate (MeJA) application could induce acquired resistance and decrease subsequent fungal or bark beetle colonization (3,4,5). To study the induced chemical changes after fungal infection and MeJA application in the phloem of mature Norway spruce, three groups, each of 24 P. abies trees of similar size, were chosen in Tönnersjöheden, southern Sweden, in May 2006. The three groups were then inoculated with C. polonica, sprayed with MeJA, or used as untreated control, respectively. Phloem samples were taken twice from each tree: on the same day as treatment and 1 mo later. The terpene composition of all the samples was analyzed by GC-MS, and the enantiomeric compositions of α-pinene, β-pinene, and limonene were analyzed by 2D-GC (6). The result indicated that both MeJA application and C. polonica infection had certain effects on the terpene composition. C. polonica infection significantly increased the biosynthesis of 3-carene, sabinene, and terpinolene. Both mean absolute amounts and relative amounts of these monoterpenes increased in samples from fungus inoculated trees, similar to what is observed in Scots pine after Leptographium wingfieldii inoculation (7). MeJA application increased the absolute amount of α-pinene, β-pinene, limonene, and some other major terpenes, but it did not change the relative amount of these terpenes. However, neither MeJA application nor fungal infection changed the enantiomeric compositions of α-pinene, β-pinene, and limonene in the phloem of Norway spruce.
Sammendrag
Norwegian field production of lettuce has increased considerably since the early 1990s. Disease problems rarely required fungicide applications before 1996, when lettuce downy mildew (Bremia lactucae) caused severe losses. From 2002 to 2004, surveys were conducted to identify fungal diseases in Buskerud, Vestfold and Ostfold counties in the south-east and Rogaland County in the south-west, representing the main lettuce production regions of Norway. The distribution and incidence of B. lactucae was highly variable, but this pathogen was the most important due to the destructive nature of uncontrolled epidemics. Septoria lactucae caused severe damage, but was found in only one field. Sclerotinia sclerotiorum was the most widespread pathogen, found in 32% of the fields, but usually affecting less than 10% of the plants. Pythium tracheiphilum was reported from 33% of the fields in south-east Norway, but was not found in the south-west. Disease incidence was usually less than 5%, and a disease incidence of more than 10% was reported in one field only. Other pathogens of potential economic importance in Norwegian lettuce fields are Alternaria spp., Botrytis cinerea and Rhizoctonia solani, although they were sporadically distributed in relatively few fields in this survey.
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Sammendrag
CSNN is common on Abies spp. both in the USA and Europe. To our knowledge the main focus on seeking an explanation to the problem has been on noninfectious/abiotic factors like nutrition and effect of shading. Thus, we decided to look into possible fungal infections on symptomatic needles. We examined samples from Nordmann fir (Abies nordmanniana) both in Norway and Austria. This resulted in a number of fungi.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
May-Guri Saethre Arnstein StaverløkkSammendrag
Funn av harlekinmarihøna Harmonia axyridis i Norge
Sammendrag
Forskere ved Skog og landskap og Universitetet for miljø- og biovitenskap (UMB) har, sammen med industrien, oppdaget at det er variasjoner i opptak av impregneringsvæske ved trykkimpregnering. Dette skyldes til dels forskjeller mellom furubestand. Den største forskjellen skyldes breddegrad. Det vil si at furu fra sørlige bredde grader lettere lar seg impregnere enn furu fra nordlige breddegrader.
Forfattere
Brita Toppe Maria Herrero May Bente BrurbergSammendrag
Fusarium foetens ble for første gang påvist i Norge i 2002 i Begonia x hiemalis. Deretter er betydlige angrep registrert i hiemalisbegonia, i den nye vertsplanten Begonia cheimanta (juleglede) og i den nye kultivaren Betulia. Utgang på mer enn 50% er observert i alle de tre vertsplantene i ulike gartneri. For identifikasjon av F. foetens ble det brukt real-time PCR basert på (mtSSU)rDNA.
Sammendrag
The last few years, increasing levels of DON (deoxynivalenol) have been recorded in Norwegian cereals, particularly in oats. In the same period, increased occurrence of F. graminearum has been reported in Norway as well as in the Western part of Europe. There may be several reasons for this change: Climate change, altered distribution of cereal cultivars, pathogen adaptation to cooler regions etc. We aim to clarify whether the increasing occurrence of F. graminearum in Norwegian cereals is connected to a change in the distribution of genotypes of this species. Fifty `old" F. graminearum isolates collected from Norwegian grown cereals during the 1990s will be compared to a similar number of `new" isolates collected in recent years (2005-2007). Isolates from Germany, Russia, Finland and the US will be used for comparisons. The genetic diversity of these about 110 isolates (50 `new", 50 `old" and 10 non-Norwegian isolates) will be investigated by AFLP (amplified fragment length polymorphism). These isolates will also be identified phylogenetically and characterised to chemotype. In addition, some selected isolates will be assessed for aggressiveness on wheat and specific characters potentially important for fungal distribution such as in vitro growth rate, spore production and perithecia formation.