Trude Vrålstad

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Identification of ectomycorrhizal (ECM) fungi is often achieved through comparisons of ribosomal DNA internal transcribed spacer (ITS) sequences with accessioned sequences deposited in public databases. A major problem encountered is that annotation of the sequences in these databases is not always complete or trustworthy. In order to overcome this(More)
As has been observed in several European countries, the frequency of Fusarium head blight (FHB) caused by members of the Fusarium graminearum species complex (FGSC) has increased in Norwegian cereals in recent years, resulting in elevated levels of deoxynivalenol in cereal grains. The objective of this study was to determine if this increase was associated(More)
Dryas octopetala is a widespread dwarf shrub in alpine and arctic regions that forms ectomycorrhizal (ECM) symbiotic relationships with fungi. In this study we investigated the fungal communities associated with roots of D. octopetala in alpine sites in Norway and in the High Arctic on Svalbard, where we aimed to reveal whether the fungal diversity and(More)
We applied quantitative TaqMan minor groove binder real-time polymerase chain reaction (PCR) on DNA isolates from soft abdominal cuticle of 460 North American crayfish Orconectes limosus and Pacifastacus leniusculus, previously tested for Aphanomyces astaci presence by conventional semi-nested PCR. Both approaches target the internal transcribed spacers of(More)
Here we present the development and first validation of a TaqMan minor groove binder (MGB) real-time polymerase chain reaction (RT-PCR) method for quantitative and highly specific detection of Aphanomyces astaci, the causative agent of crayfish plague. The assay specificity was experimentally assessed by testing against DNA representative of closely related(More)
• Fungi in the Rhizoscyphus ericae aggregate have been recovered from the roots of co-occurring ericaceous shrubs and ectomycorrhizal trees. However, to date, there is no evidence that the same individual genotypes colonize both hosts, and no information on the extent of the mycelial networks that might form. • Using spatially explicit core sampling, we(More)
The hypothesis that the postfire discomycete Geopyxis carbonaria (Ascomycota, Pezizales, Pyronemataceae) has a biotrophic association with roots of Norway spruce (Picea abies) in nature was tested by isolation of fungal strains from fresh, brown, smooth mycorrhiza-like root tips of Norway spruce collected from below the depth of detrimental heat penetration(More)
Aphanomyces astaci is an invasive pathogenic oomycete responsible for the crayfish plague, a disease that has devastated European freshwater crayfish. So far, five genotype groups of this pathogen have been identified by applying random amplified polymorphic DNA analysis on axenic cultures. To allow genotyping of A. astaci in host tissue samples, we have(More)
Noble crayfish Astacus astacus is threatened in Europe due to invasive crayfish carrying the crayfish plague agent Aphanomyces astaci. Norway is among the last countries in which the introduction of non-indigenous crayfish has been limited through strict legislation practices. However, North American signal crayfish Pacifastacus leniusculus were recently(More)