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
Sammendrag
In Norway, Nordmann fir (Abies nordmanniana) and subalpine fir (A. lasiocarpa) are the dominant Christmas tree species, and noble fir (A. procera) the dominant bough plant species. To determine if fungi found to cause diseases on fir in Norway might be seed borne, samples from twelve seed lots, including Nordmann fir from Austria, Georgia and Russia, subalpine fir from Canada and Norway and noble fir from Norway were tested using agar plate methods (PDA and WA). The most important finding was that Sydowia polyspora was present on seed from all firs from all countries (nine samples infected, 0.5 - 85 % infected seeds). Recently, it has been demonstrated in Norway that this fungus is the cause of current season needle necrosis (CSNN), which is considered a major disease in the Christmas tree and bough production both in Europe and USA. Sirococcus coniguenus was found in a Norwegian A. procera seed lot (31% infected seeds), which to our knowledge is the first report of this pathogen on fir seeds. Caloscypha fulgens was detected on subalpine fir seed from Canada. In addition the following fungal genera were detected: Acremoniella, Acremonium, Alternaria, Aspergillus, Botrytis, Chaetomium, Cladosporium, Diaphorte, Dictyopolyschema, Epicoccum, Fusarium, Genicularia, Mucor, Neonectria, Penicillium, Phoma, Rhizopus, Sordaria, Trichoderma, Trichothecium, and an unidentified fungus.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Aruppillai Suthaparan Arne Stensvand Sissel Torre Maria Herrero Rolf Inge Pettersen David Gadoury Hans Ragnar GislerødSammendrag
The effect of day length on production and germinability of conidia and severity of disease caused by Podosphaera pannosa, the causal agent of rose powdery mildew, was studied. Whole potted plants or detached leaves of Rosa interspecific hybrid 'Mistral' were inoculated with P. pannosa and exposed to 0, 12, 18, 20, 22, or 24 h of artificial light per day in growth chambers equipped with mercury lamps. Increasing duration of illumination from 18 to 20 to 24 h per day reduced production of conidia by 22 to 62%. Exposure to 24 h of illumination per day also strongly reduced disease severity compared with 18 h. Our results suggest that increasing day lengths from 18 h per day to 20 to 24 h may suppress the disease significantly and, thereby, reduce the need for fungicide applications against powdery mildew.
Sammendrag
The anamorph genus Leptographium Lagerberg and Melin includes species that are typically bark beetleassociated fungi, with teleomorphs in Grosmannia. During a survey of ophiostomatoid fungi in Norway, two unusual species, that fit the broader morphological description of Leptographium, were isolated directly from the rootfeeding beetles, Dryocetes authographus and Hylastes cunicularius, as well as from roots infested by these insects. The first of these could be distinguished from other described species based on a sparse sporulation, black spore drops and chlamydospores in older cultures. This species also produces a Hyalorhinocladiella synanamorph. The second species was characterised by distinctly curved conidia. Based on these unusual morphological characteristics and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium chlamydatum sp. nov. and L. curvisporum sp. nov. are provided.
Forfattere
Tao Zhao Paal Krokene Niklas Björklund Bo Långström Halvor Solheim Erik Christiansen Anna-Karin Borg-KarlsonSammendrag
Constitutive and inducible terpene production is involved in conifer resistance against bark beetles and their associated fungi. In this study 72 Norway spruce (Picea abies) were randomly assigned to methyl jasmonate (MJ) application, inoculation with the bluestain fungus Ceratocystis polonica, or no-treatment control. We investigated terpene levels in the stem bark of the trees before treatment, 30 days and one year after treatment using GC–MS and two-dimensional GC (2D-GC) with a chiral column, and monitored landing and attack rates of the spruce bark beetle, Ips typographus, on the trees by sticky traps and visual inspection. Thirty days after fungal inoculation the absolute amount and relative proportion of (+)-3-carene, sabinene, and terpinolene increased and (+)-α-pinene decreased. Spraying the stems with MJ tended to generally increase the concentration of most major terpenes with minor alteration to their relative proportions, but significant increases were only observed for (−)-β-pinene and (−)-limonene. Fungal inoculation significantly increased the enantiomeric ratio of (−)-α-pinene and (−)-limonene 1 month after treatment, whereas MJ only increased that of (−)-limonene. One year after treatment, both MJ and fungal inoculation increased the concentration of most terpenes relative to undisturbed control trees, with significant changes in (−)-β-pinene, (−)-β-phellandrene and some other compounds. Terpene levels did not change in untreated stem sections after treatment, and chemical induction by MJ and C. polonica thus seemed to be restricted to the treated stem section. The enantiomeric ratio of (−)-α-pinene was significantly higher and the relative proportions of (−)-limonene were significantly lower in trees that were attractive to bark beetles compared to unattractive trees. One month after fungal inoculation, the total amount of diterpenes was significantly higher in putative resistant trees with shorter lesion lengths than in putative susceptible trees with longer lesions. Thus, terpene composition in the stem bark may be related to resistance of Norway spruce against I. typographus and C. polonica.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Toril Drabløs Eldhuset Isabella Børja Nicholas Clarke Kjersti Holt Hanssen O. Janne Kjønaas Holger Lange Ingvald Røsberg Tonje ØklandSammendrag
Hogstavfall er nøkkelen til økt satsing på bioenergi i Norge. Men vil dette påvirke bærekraften i skogøkosystemet og skogproduksjonen? Blir skogsjorda mer næringsfattig? Endres sammensetningen av arter i vegetasjonen? Vil artsmangfoldet bli redusert? Blir det mindre av de soppene som bryter ned planterester? Dette er noen av spørsmålene vi prøver å besvare gjennom prosjektet «Økologiske virkninger av økt biomasseuttak fra skog i Norge» (ECOBREM), som varer fra 2009 til 2013.
Sammendrag
We monitored the effects of the drought stress on 20-year old clones of Norway spruce (Picea abies) by using a range of instrumental methods. On two experimental plots (Hoxmark, Norway, 59°40\"14`N, 10°47\"36`E) the drought was induced in a period between May and October 2009 by removing the throughfall using the rain shelters and trenching. We collected data on soil moisture, stem and branch sap flow, xylem diameter, anatomical and calorimetric analysis of the needles, fine root biomass and dynamics and resistance to pathogens. Standard meteorological data were collected locally throughout the whole period. Here we present the preliminary analysis of sap flow and xylem diameter in a period 1-17 august 2009. The sap flow was measured on stems in the breast height by using the method of stem tissue heat balance (THB, EMS Brno). The values were measured once in 2 minutes and saved as the average of 10 minutes. The fluctuations in xylem diameter was monitored by using the automatic dendrometers DR26 (EMS Brno). We evaluated both diurnal and seasonal dynamics. Preliminary results show a significant difference in shape of diurnal curves of transpiration as well as different time lag among the sap flow and the potential evapo-transpiration. Also the differences in diurnal dynamics of the stem circumference suggested different xylem water potential in stressed and control trees. In the drought-stressed trees the diurnal fluctuation in stem diameter was about 4 times higher and the total stem increment one third lower, com-pared to the control trees.
Sammendrag
Det er ikke registrert sammendrag