Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2008
Authors
Carl Jonas Jorge SpetzAbstract
No abstract has been registered
Abstract
Pine Wood Nematode (PWN, Bursaphelenchus xylophilus) is the causal organism of Pine Wilt Disease (PWD), the worst forest pest of Japan. In Europe PWN is known to exist in Portugal. The Norwegian Food Safety Authority (Mattilsynet) is concerned about the plant health risks and the consequences to the society if PWN should establish in Norway. Mattilsynet needs a scientific assessment of the proposed measures in a contingency plan for PWN. Mattilsynet also needs the risks connected with recent spread of PWN in Portugal to be evaluated before possible changes can be made in the current phytosanitary policy of Norway. On this background Mattilsynet requested a pest risk assessment of PWN from the Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM). To answer the request, VKM commissioned a draft pest risk assessment report from the Norwegian Institute for Agricultural Sciences and Environmental Research (Bioforsk). A working group appointed by VKM’s Panel on Plant Health (Panel 9) has been involved during Bioforsk’s work on the report. VKM’s Panel 9 has used the report as a basis for VKM’s opinion. The current document answers Part 1 of Mattilsynet’s request, and was adopted by Panel 9 on a meeting 3rd September 2008. VKM’s Panel 9 gives the following main conclusions of the risk assessment: The PRA area of this assessment is Norway. PWN is not known to occur in Norway. With present trade pattern the probability of entry of PWN into Norway is expected to be high. The most probable pathway for entry of PWN into Norway would be wood packaging material (WPM). The probability that PWN will establish and spread in Norway is considered as high. With regard to the so-called Pest Free Areas (PFAs) of Portugal, the criteria given in ISPM No. 4 (FAO 1995) for establishing and maintaining PFAs have not been met, and the data available is not sufficient to confirm the existence of PFAs. Acceptance of untreated conifer wood from all parts of Portugal will result in a very high probability of entry and a high probability of establishment and spread of PWN and its vector to Norway. Uncertainty factors: To the best of our knowledge PWN is absent from the PRA area. The beetle M. sutor is regarded as a potential vector or PWN, but this has so far not been demonstrated in nature. The currently low vector densities may retard establishment of the PWN and PWD, but it will probably not stop establishment in a longer perspective. Lack of information on the dynamics of PWN populations in cool climates complicates estimates of the spread of the nematode and PWD. Custom routines may fail in their detection of PWN. Import of a seemingly harmless material might therefore pose an unknown risk. WPM follows consignments of all kinds and is a good example of a hazardous material, which often escapes plant health inspections. Detailed assessments of economic consequences of a possible establishment and spread of PWN in Norway, the effects of global warming and other climate changes on the probability for PWD outbreaks, and the effect of possible phytosanitary measures, will be given in Part 2.
Authors
Jihong Liu Clarke Carl Jonas Jorge Spetz Sissel Haugslien Shaochen Xing Merete Dees Roar Moe Dag-Ragnar BlystadAbstract
Agrobacterium-mediated transformation for poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch) is reported here for the first time. Internode stem explants of poinsettia cv. Millenium were transformed by Agrobacterium tumefaciens, strain LBA 4404, harbouring virus-derived hairpin (hp) RNA gene constructs to induce RNA silencing-mediated resistance to Poinsettia mosaic virus (PnMV). Prior to transformation, an efficient somatic embryogenesis system was developed for poinsettia cv. Millenium in which about 75% of the explants produced somatic embryos. In 5 experiments utilizing 868 explants, 18 independent transgenic lines were generated. An average transformation frequency of 2.1% (range 1.2-3.5%) was revealed. Stable integration of transgenes into the poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Both single- and multiple-copy transgene integration into the poinsettia genome were found among transformants. Transgenic poinsettia plants showing resistance to mechanical inoculation of PnMV were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Northern blot analysis of low molecular weight RNA revealed that transgene-derived small interfering (si) RNA molecules were detected among the poinsettia transformants prior to inoculation. The Agrobacterium-mediated transformation methodology developed in the current study should facilitate improvement of this ornamental plant with enhanced disease resistance, quality improvement and desirable colour alteration. Because poinsettia is a non-food, non-feed plant and is not propagated through sexual reproduction, this is likely to be more acceptable even in areas where genetically modified crops are currently not cultivated.
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
The main Avena species that are important weeds of cereal and arable crops include A. fatua L., A. sterilis and A. barbata Pott. All three species have an abscission scar on the grains. A risk assessment of A. fatua L. as an indirect pest in Norway is given in a separate document. For both A. sterilis ssp. macrocarpa and ssp. maxima, and for A. barbata Pott, the potential for entry and establishment in Norway is considered as very low. A. sterilis ssp. ludoviciana (winter wild oats) has a moderate potential for establishment in Norway. The suitability of the environment for A. sterilis ssp. ludoviciana was therefore investigated: Our assessment of the probability of establishment indicates that the climate is not favourable for establishment of A. sterilis ssp. ludoviciana in Norway. A. sterilis ssp. ludoviciana is a problem in southern Europe and central southern England and is mainly a weed in winter cereals. While it is highly likely that the probability of establishment of A. sterilis ssp. ludoviciana has increased in Norway in recent years due to climate change and consequent changes in cultural practices, its probability of establishment in Norway is still low and it is therefore not likely that it will become a weed in Norway under current conditions. However, if the future climate of the PRA area changes, so that winter conditions become similar to conditions in southern England, while the acreage of winter cereal continues to grow, A. sterilis ssp. ludoviciana could become a weed in Norway. A. sterilis ssp. ludoviciana is not present in Denmark where winter cereals are much more widely cultivated, and the climate is more favourable than in Norway. One would therefore expect the weed to establish in Denmark before it will become a problem in Norway
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
No abstract has been registered
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
In 2007, after many years of absence, Cucumber Green Mottle Mosaic Virus (CGMMV) reoccurred in Norwegian cucumber production. The Norwegian Food Safety Authority is considering to regulate CGMMV as a quarantine pest and commissioned a Pest Risk Analysis (PRA) of the virus. The Panel of Plant Health gives the following conclusions: Both recent and previous presence of CGMMV indicate that the pest is able to establish in the PRA area. The most probable pathway for long distance spread into the PRA area is seed transmission. Infected seedlings, people, water and soil are probable pathways for short distance spread. The probability of further spread is from location to location is high. Dry heat treatment has probably been the most effective measure to prevent the spread of CGMMV. There is a moderate level of uncertainty regarding the pathway for entry of CGMMV into the PRA area. There is a low degree of uncertainty regarding the pathogen survival and possibilty for transmission, establishment and spread in Norwegian greenhouse cucumber production.
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
No abstract has been registered
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
No abstract has been registered
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
Wild oats (A. fatua) is present in 155 out of 431 Norwegian municipalities. It is widely distributed in all municipalities in the main agricultural areas in south-east and central-east Norway, and in the municipalities close to the Trondheim fjord. Otherwise wild oats is present in only a few scattered municipalities not geographically connected to these main areas. Endangered area, not yet infested by A. fatua, is estimated to 228858 ha. This area is spread over the cereal growing part of Norway. The counties of North- and South -Trøndelag have a higher portion of endangered area not yet infested than south and central part of East Norway. The probability of entry of A. fatua from outside the PRA area (Norway) is very low. The probability of spread within Norway is high. In areas with low infestation, like in Trøndelag, the probability of spread is lower than in heavily infested areas. However, in areas with high level of infestation there are few new farms left to be infested. The official wild oats register is a valuable tool in regulations aiming to limit spread. The register also provides a tool to follow up infested farms. The register would be even more useful if inspection for infestation on new farms had been more systematic. Wild oats is no longer devastating even in cereal monocropping, due to cost efficient herbicides. However, in Norway an increasing area is infested with wild oats. The infestation may vary from only a few plants to total coverage of the field. In cereal monocropping chemical treatment with and without hand roguing is the only feasible control methods. Hand roguing alone is expensive and ineffective even on modest infestation. The structural changes in cereal farming result in more farms being managed by entrepreneurs. Field managed by entrepreneurs promotes use of herbicide even on small infestations since this is a cost effective measure to control the weed. Less official control of cereal fields can also be expected. The economical consequences are thus expected to be high. The economical consequences can be even higher in organic farming if the most profitable rotation has to be changed to a less profitable one because of wild oats infestation.
2007
Authors
Christer Magnusson Karl Thunes Hans Nyeggen Hans Overgaard Trond Rafoss Solveig Haukeland May Bente Brurberg K. A. Strandenæs Bjørn Økland Bonsak HammeraasAbstract
The detection in 1999 of the pine wood nematode (PWN), Bursaphelenchus xylophilus, in Portugal triggered survey activities in many European countries. With the assumption that PWN would reach frequency 10 times lower than the native B. mucronatus and the requirement of a 95 % confidence limit suggested 2 995 samples to be required for a safe statement on the absence of PWN from the territory surveyed. Samples were taken from 10 circular areas with 50 km diameter erected from a point of import of risk materials. In the period 2000-2006 3 165 wood samples, 2 880 from Pinus sylvestris, 279 from Picea abies and 6 from unknown wood, were collected from 446 logging sites, in 84 municipalities and 13 counties. Of the total material 85 % of the samples came from cutting wastes, timber or lying trees. Wood showing signs of insect activity (incl. Monochamus) formed 73 % of the total material. Nematodes were recorded in 85 % of the samples. The order Rhabditida was most frequent, followed by the orders Aphelenchida, Tylenchida and Dorylaimida. Rhabditid nematodes were equally frequent in pine and spruce, while Aphelenchida (Aphelenchus, Aphelenchoides, Cryptaphelenchus, Seinura and Bursaphelenchus) and Tylenchida (Filenchus, Lelenchus, Ditylenchus, Deladenus and Nothotylenchus) tended to be more common in pinewood. Aphelenchoides was the most common genus. The genus Bursaphelenchus occurred in 1 % of the samples. B. mucronatus was detected in 0,3 % of the samples and most often in cutting waste of pine. The pine wood nematode (PWN), B. xylophilus, was not detected in this survey. The unexpected low natural occurrence of B. mucronatus indicates that the number of potential niches for PWN also is lower than expected, and hence it will be necessary to continue this surveillance program to reach 10 000 samples. The present zone sites in central and south-eastern Norway will be supplemented with 1-2 zone sites in southwestern region of the country. In the future these zone sites will function as permanent observation areas. Care will also be taken to collect all samples from detached wood with signs of Monochamus activity.