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.
2016
Authors
Louise C. Ross Gunnar Austrheim Leif Jarle Asheim Gunnar Bjarnason Jon Feilberg Anna Maria Fosaa Alison J. Hester Øystein Holand Ingibjörg S Jónsdóttir Lis E. Mortensen Atle Mysterud Erla Olsen Anders Skonhoft James David Mervyn Speed Geir Steinheim Des B.A. Thompson Anna G. ThorhallsdottirAbstract
Sheep grazing is an important part of agriculture in the North Atlantic region, defined here as the Faroe Islands, Greenland, Iceland, Norway and Scotland. This process has played a key role in shaping the landscape and biodiversity of the region, sometimes with major environmental consequences, and has also been instrumental in the development of its rural economy and culture. In this review, we present results of the first interdisciplinary study taking a long-term perspective on sheep management, resource economy and the ecological impacts of sheep grazing, showing that sustainability boundaries are most likely to be exceeded in fragile environments where financial support is linked to the number of sheep produced. The sustainability of sheep grazing can be enhanced by a management regime that promotes grazing densities appropriate to the site and supported by area-based subsidy systems, thus minimizing environmental degradation, encouraging biodiversity and preserving the integrity of ecosystem processes.
Authors
Erik Lysøe Rasmus J.N. Frandsen Hege Divon Valeria Terzi Luigi Orrù Antonella Lamontanara Anna-Karin Kolseth Kristian F. Nielsen Ulf ThraneAbstract
Fusarium langsethiae is a widespread pathogen of small grain cereals, causing problems with T-2 and HT-2 toxin contamination in grains every year. In an effort to better understand the biology of this fungus, we present a draft genome sequence of F. langsethiae Fl201059 isolated from oats in Norway. The assembly was fragmented, but reveals a genome of approximately 37.5 Mb, with a GC content around 48%, and 12,232 predicted protein-coding genes. Focusing on secondary metabolism we identified candidate genes for 12 polyketide synthases, 13 non-ribosomal peptide synthetases, and 22 genes for terpene/isoprenoid biosynthesis. Some of these were found to be unique compared to sequence databases. The identified putative Tri5 cluster was highly syntenic to the cluster reported in F. sporotrichioides. Fusarium langsethiae Fl201059 produces a high number of secondary metabolites on Yeast Extract Sucrose (YES) agar medium, dominated by type A trichothecenes. Interestingly we found production of glucosylated HT-2 toxin (Glu-HT-2), previously suggested to be formed by the host plant and not by the fungus itself. In greenhouse inoculations of F. langsethiae Fl201059 on barley and oats, we detected the type A trichothecenes: neosolaniol, HT-2 toxin, T-2 toxin, Glu-HT-2 and numerous derivatives of these.
Authors
Mogens Lund Jørgen Dejgård JensenAbstract
The aim of the article is to identify and analyse public-private incentives for the development and marketing of new animal vaccines within a real options methodological framework, and to investigate how real options methodology can be utilized to support economic incentives for vaccine development in a cost-effective way. The development of a vaccine against Campylobacter jejuni in poultry is applied as a case study. Employing the real options methodology, the net present value of the vaccine R&D project becomes larger than a purely probabilistic expected present value throughout the different stages of the project − and the net present value becomes larger, when more types of real options are taken into consideration. The insight from the real options analysis reveals opportunities for new policies to promote the development of animal vaccines. One such approach might be to develop schemes combining stage-by-stage optimized subsidies in the individual development stages, with proper account taken of investors’/developers' economic incentives to proceed, sell or cancel the project in the respective stages. Another way of using the real options approach to support the development of desirable animal vaccines could be to issue put options for the vaccine candidate, enabling vaccine developers to hedge against the economic risk from market volatility.
Authors
Misganu Debella-GiloAbstract
Det er ikke registrert sammendrag
Abstract
Herbivory by insects and mites on physic nut (Jatropha curcas L.) seedlings was investigated and compared with irrigation in the semi-arid Sahelian Niger, utilizing a randomized complete block design experiment. Three water treatment protocols were applied and the types of damage were recorded. Less than 5% of the seedlings died during the 10-month trial period with sap suckers causing the most damage on the surviving plants. Plants with high production of biomass and leaf cover (foliage) were most strongly positively correlated with irrigation and were also the plants that endured the highest degree of herbivory. The low dieback may indicate that defence mechanisms counteract seedling herbivory and that drought-stressed plants invest more in their defence mechanism system than vital plants.
Abstract
The effect of fertility status and temperature conditions during floral induction on flowering, berry yield,and weight and drupelet numbers of individual berries were studied in ‘Glen Ample’ raspberries grownunder controlled conditions. Withdrawal of normal fertilization prior to and at various stages duringfloral induction did not affect yield and berry size, but marginally advanced flowering and fruit ripening.The successive stages of floral initiation and differentiation were studied and identified by scanning elec-tron microscopy of the uppermost lateral buds of plants grown for six weeks under naturally decreasingautumn photoperiods at temperatures of 9, 15 and 21◦C. Low temperature advanced floral initiation, andadvanced and enhanced flowering and berry yield in the following season. However, at variance fromearlier studies, the plants eventually initiated flower primordia even at 21◦C. Marginal low temperatureand short day conditions during the last days before the temperature treatments were started on 17September might possibly have reduced the subsequent induction requirements enough to explain thisunexpected result. Correlation analyses revealed an over-all positive correlation between fruit weightand drupelet numbers (r = 0.568, P = 0.01). In berries from the early harvests, the number of drupelets perberry increased with decreasing temperature, while the numbers converged to the same level regardlessof temperature in the later harvests. Based on the progress of the floral initiation process at the vari-ous temperatures, we interpret this to mean that only the early initiated flowers, that gave rise to theearly maturing berries, were differentiated during the actual period of controlled temperature exposure,whereas the remaining flowers were differentiated afterwards when all plants were exposed to identicallow temperature conditions. Increased femaleness under optimal floral induction conditions is in agree-ment with results in both monoecious and dioecious plants and circumstantial evidence suggest that,in the raspberry, this might be mediated by changes in gibberellin activity which acts as a male sexualhormone in plants and is known to inhibit growth cessation and floral initiation in raspberry.
Abstract
Det er ikke registrert sammendrag
Authors
Yanliang Wang Tore Krogstad Jihong Liu Clarke Moritz Hallama Anne K. Falk Øgaard Susanne Eich-Greatorex Ellen Kandeler Nicholas ClarkeAbstract
Det er ikke registrert sammendrag
Authors
Jing Liu Huang Peng Jiangkuan Cui Wenkun Huang Lingan Kong Jihong Liu Clarke Heng Jian Guo Liang Wang Deliang PengAbstract
Cereal cyst nematodes are sedentary biotrophic endoparasites that maintain a complex interaction with their host plants. Nematode effector proteins are synthesized in the oesophageal glands and are secreted into plant tissues through the stylet. To understand the function of nematode effectors in parasitic plants, we cloned predicted effectors genes from Heterodera avenae and transiently expressed them in Nicotiana benthamiana. Infiltration assays showed that HaEXPB2, a predicted expansin-like protein, caused cell death in N. benthamiana. In situ hybridization showed that HaEXPB2 transcripts were localised within the subventral gland cells of the pre-parasitic second-stage nematode. HaEXPB2 had the highest expression levels in parasitic second-stage juveniles. Subcellular localization assays revealed that HaEXPB2 could be localized in the plant cell wall after H. avenae infection.This The cell wall localization was likely affected by its N-terminal and C-terminal regions. In addition, we found that HaEXPB2 bound to cellulose and its carbohydrate-binding domain was required for this binding. The infectivity of H. avenae was significantly reduced when HaEXPB2 was knocked down by RNA interference in vitro. This study indicates that HaEXPB2 may play an important role in the parasitism of H. avenae through targeting the host cell wall.
Authors
Irene Biancarosa Marit Espe Christian Guido Bruckner Svenja Heesch Nina Sylvia Liland Rune Waagbø Bente Elisabeth Torstensen Erik-Jan LockAbstract
The Norwegian seaweed industry is expanding and there is a need for accurate estimates of protein content of seaweed species from Norwegian waters. A solid method to calculate protein content is through the sum of the proteomic amino acids; however, it can be expensive and beyond the capacities of many laboratories. The most commonly used method to quantify protein is based on the assessment of crude protein from overall nitrogen content, using the traditional nitrogen-to-protein conversion factor of 6.25. However, this approach can be inaccurate when applied to seaweeds, often resulting in an overestimation of their protein content. Specific nitrogen-to-protein conversion factors, calculated from amino acid composition and total nitrogen, give a more reliable protein quantification in seaweeds. However, no such factors are available for species from Norwegian waters. This study was designed to characterize the amino acid composition of 21 seaweed species from Norwegian waters and use the amino acid data to estimate protein contents of the seaweeds. Crude protein analysis (nitrogen × 6.25) was performed and resulted in overestimation (18–44 %) of the protein content compared to the sum of proteomic amino acids. Specific nitrogen-to-protein conversion factors, calculated for each species, ranged from 3.53 ± 0.1 to 5.13 ± 0.1. This study provides nutritional data on Norwegian seaweeds, covering a relatively wide range of species. Moreover, it is the first study to assess nitrogen-to-protein conversion factors on such species.