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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

Sammendrag

During the last years, Norway and several other countries have seen an increase in potato blackleg disease caused by the Gram-negative bacterium Pectobacterium atrosepticum (formerly known as Erwinia carotovora ssp. atroseptica). P. atrosepticum has a narrow host range, limited almost exclusively to potato plants in temperate regions, where it also causes soft rot of potato tubers. The pathogen spreads from infected seed tubers to progeny tubers either through the plant or over short distances in the soil. However, little is known about how seed potatoes are initially contaminated with the bacterium and what onsets the infection. Our overall aim is to understand the underlying molecular mechanisms behind potato infection by P. atrosepticum and to find possible means of controlling blackleg disease, as well as providing more knowledge of the overall lifestyle of the bacterium. The sequencing and annotation of the genome of P. atrosepticum strain SCRI1043 (Bell et al., 2004. Proc.Natl.Acad.Sci. 101: 11105-10) as well as a genome-wide mutant library (Holeva et al., 2004. Mol. Plant. Microbe. Interact. 17:943-50) provide valuable tools in examining the molecular aspects of both pathogenesis and environment related factors. Quorum-sensing seems to play an essential role in the pathogenesis of P. athrosepticum, and we are currently studying some of the many genes affected by this regulatory control as well as other putative virulence genes.

Sammendrag

The five mint genera Brazoria, Macbridea, Physostegia, Synandra and Warnockia (Lamioideae: Lamiaceae) are all North American endemics. Together with the monotypic European genus Melittis and the Asian genus Chelonopsis, these taxa have been classified as subtribe Melittidinae. Previous morphological studies have failed to uncover synapomorphic characters for this group.We sequenced the plastid trnL-trnF region and trnS-trnG spacer and the nuclear ribosomal 5S non-transcribed spacer (5S-NTS) to assess phylogenetic relationships within Melittidinae. Standard parsimony and direct optimization (POY) analyses show Melittis, the type genus of the subtribe, as sister to Stachys. Thus, the monophyly of subtribe Melittidinae is not supported either by molecular or morphological data...

Sammendrag

The root-rot causing fungus Heterobasidion annosum sensu lato is the most devastating pathogen of conifers in Europe. This pathogen enters Norway spruce through the roots and can colonize the tree from within, growing as a saprophyte when established within the dead heartwood and acting as a necrotroph when in contact with living host tissue. Despite the high incidence of damage, trees have defences against this pathogen in the bark and living wood. Furthermore, spruce has a defense against internal attack by forming a reaction zone, in this case the host defense is directed inwardly by the still living sapwood toward the central colonized heartwood. We have studied the host responses to infection in Norway spruce clones at the transcriptional level and found that the speed of recognition and that spatial defense signalling appears to be the hallmarks of trees with high degree of resistance...

Til dokument

Sammendrag

This paper discusses the monitoring network for diffuse pollution from agriculture in Estonia in the context of implementation of the EU Water Framework Directive (WFD) and the Nitrate Directive (ND). Seven surface water monitoring stations in agricultural catchments represent two out of three river basin districts designated in Estonia according to the WFD criteria. The national monitoring programme of ground water quality involves 516 stations of which about half were monitored in 2005. The monitoring sites cover all main ground water bodies in Estonia but are largely concentrated in the Nitrate Vulnerable Zone (NVZ). Analyses did not reveal any significant trends in total nitrogen (TN) and total phosphorus (TP) concentrations in studied rivers during the last 15 years except in one site. The ground water quality stabilised after decrease of nitrate concentrations in the early 1990s, especially in the south part of the NVZ, but even in 2005 the nitrate concentration exceeded 50 mg l1 in 42 out of 145 ground water samples in this region. The existing surface water quality monitoring network provides only restricted information to select between different management options when implementing action programmes for the NVZ and the river basin management plans (RBMP) under the WFD.

Sammendrag

The sex pheromone of the raspberry cane midge has been identified and synthesised by East Malling Research and Natural Resourced Institute and has proved to be highly attractive and useful for pest monitoring. EMR coordinated a collaborative ring test of standard raspberry cane midge sex pheromone traps in 2006. The aims were to investigate the seasonal temporal pattern of the midge flight in different raspberry production regions of Europe and the relationship between the magnitude of catches and the numbers of eggs and larvae which developed subsequently in artificial splits in the primocane of untreated raspberry plantations. The standard raspberry cane midge sex pheromone trap used for the ring test consisted of a white delta trap containing a 20 x 20 cm sticky base and a rubber septum lure impregnated with 10 μg of the raspberry cane midge sex pheromone racemate. Pairs of traps, separated by >20 m, were deployed in the centre of raspberry plantations at a height of 0.5 m in Italy, Hungary, Norway, Poland, Russia, Serbia, Sweden, Switzerland, and the UK. The traps proved effective and easy to use for monitoring the flight of adult male raspberry cane midge. There were very large variations (> 30 fold) between plantations in total numbers of midges caught over the season, indicating plantations which are at comparatively low and high risk from the pest.  Three generations of adult flight were apparent in Norway, Russia and Sweden and four generations in the central European countries with possibly 5 generations in Italy, though later generations were often difficult to distinguish. In the northern countries, the 1st generation first and peak flight occurred on Julian days 150 and 165, respectively, whereas in Italy the 1st generation first and peak flight occurred approximately on Julian days 110 and 130 respectively. The 1st generation flights occurred much earlier in polytunnel protected crops than in open field crops.  Data obtained on the occurrence of larvae were variable in quality but a linear relationship between the peak numbers of males captured in the pheromone traps per week for a given generation (M) and the peak numbers of eggs and larvae per cm in splits in the primocanes for that generation subsequently (L) was apparent (L = 0.025 M; R2=0.61). A nominal threshold of 30 midges per trap per week had been proposed but the linear relationship derived indicates that this threshold, which would result in ~ 0.75 eggs + larvae/cm, is too high. In reality, the degree of larval infestation that occurs and the resultant severity of crop damage will depend on the numbers of natural splits in the crop. The ring test is being continued in several countries in 2007.

Sammendrag

Tidligere ertedyrking i Norge blir omtalt. Ertenes krav til jord og klima behandles. Forandringer av sortenes egenskaper ved foredling blir omtalt. Ertenes egenskaper og bruksområder og de gode mulighetene for ertedyrking på Toten og i Mjøsområdet blir framhevet.