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
Forfattere
Kenan Kanlic Belma Kalamujic Jasmin Grahic Åsmund Asdal Mekjell Meland Mirsad Kurtovic Fuad GasiSammendrag
Triploid apple cultivars are often favored by human selection due to their increased fruit size, even though they possess higher requirements in terms of pollination compared to their diploid counterparts. However, similar to the sensory characteristics, preferences for the size and shape of apple fruit are not universal, but culturally dependent. In order to investigate the influence of selection pressure on the frequency of triploid genotypes among different traditional apple germplasms, 141 apple accessions maintained in ex situ collections in Norway and 115 traditional and international apple accessions from Bosnia and Herzegovina (B&H) were analyzed using 8 microsatellite markers. Genotypes possessing more than two alleles per locus were deemed to be triploid. The results of SSR analyses from this and comparable studies indicate that the triploid apple cultivars are much more frequent among the traditional apple germplasm from Southern Europe than they are among the traditional apple germplasm from Northern Europe. The possible causes for these results are also discussed.
Forfattere
Mekjell Meland Eivind Vangdal Clive KaiserSammendrag
The European plum cultivar 'Opal', widely grown in Scandinavia, frequently initiates too many flowers and set too many fruits. If excess fruitlets remain on the trees until harvest, the crop consists of small, unmarketable fruits of low fruit quality and return bloom will be reduced. The current study investigated effects of different crop loads established at blossom and fruitlet stages on yield, fruit quality and return bloom. For two seasons starting in 2008 on mature 'Opal'/'St. Julien A' trees, two crop loads 50 and 25% flowers reduced were established at full bloom and at 10-12 mm fruitlet size and compared with an un-thinned control treatment. Treatments were applied on single whole trees in a randomized complete block design with six replications. Spindle trees spaced at 3.0×5.0 m were selected for uniformity in growth habit, flowering intensity and trunk cross sectional area. Final fruit set varied from 63% on the control trees to 18% when thinned at bloom. Yield was negatively correlated with the fruit set response. Thinning at the fruitlet stage resulted in smaller fruits at the same crop level compared to flower thinning. Fruit quality parameters characterized by bright yellow skin background colour, red surface colour and the concentrations of soluble solids increased significantly as the crop load was reduced. Other fruit quality parameters like percentage acidity were not significantly different and did not show a clear response to the thinning. Return bloom was promoted most when trees were thinned at bloom the year before.
Forfattere
Andrius Kuliesis Stein Michael Tomter Claude Vidal Adrian LanzSammendrag
Key message Quality and reliability of forest resource assessments depend on the ability of national forest inventories (NFIs) to supply necessary and high-quality data. Over the last decades and especially since the 1990s, the NFIs in European countries have been rapidly developing. Possibilities for obtaining reliable and accurate data on annual increment from different inventory types were evaluated, and sample-based inventories have been found to be superior to standwise inventories in providing reliable data. Simplified methods may be employed when increment cannot be directly estimated from inventory data. Context An increasing intensity of forest resource use requires more accurate, detailed and reliable information, not only on forest area and growing stock but also on forest stand productivity, wood increment and its components. Aims The main objectives were to assess the capacities of forest inventories, the methods used for estimation of gross increment and its components and their accuracy and to demonstrate an effective method for estimation of increment when direct inventory methods are not available. Methods Data about national forest inventory methods were obtained from 30 responses to a questionnaire, distributed amongst national correspondents of all European countries; reports of COST Actions E43 and FP 1001, databases of Temperate and Boreal Forest Resource Assessment (TBFRA) 2000 and State of Europe’s Forests (SoEF) 2011 were used as well. Analysis and comparison of results from different forest inventories were used for evaluation of data reliability. Relationships between growing stock and gross increment in European forests were also analysed, and corresponding models were proposed. Results Seventy-nine percent of European forest area is covered by national forest inventories (NFIs) based on sampling methods and the rest on stand-level inventory and other inventory methods. Data obtained by aggregating standwise data usually underestimate growing stock by 15–20 % and gross increment even more. Almost half of the European forest area (47 %) is monitored using permanent plots, measured twice or more, allowing the estimation of gross increment and its components to be made directly. Conclusion Implementation of NFIs based on sampling methods, especially with permanent plots, resulted in an improvement of data quality and in most cases an increase of growing stock and gross increment. The estimation of natural losses is the weakest link in today’s NFIs and in the current assessment of European forest resources. The proposed default values for gross increment and its components is an option to be used in countries not having NFI at all or those which have started it only recently.
Forfattere
Fuad Gasi Kenan Kanlic Belma Kalamujic Stroil Naris Pojskic Åsmund Asdal Morten Rasmussen Clive Kaiser Mekjell MelandSammendrag
Apple genetic resources in Norway are currently conserved within a number of local clonal archives. However, during establishment of these ex situ collections, primary focus was not on capturing as much of the diversity as possible, but instead on preserving cultivars of particular importance to specific fruit-growing areas. To identify redun- dancies within the collection as well as to assess the genetic diversity and structure of apple germplasm currently being conserved in Norway, eight microsatellites were used in genetic characterization of 181 apple accessions. Overall, 14 cases of synonym or possibly mislabeled accessions were identified, as well as several homonyms and duplicates within and among the analyzed collections. The information obtained should contribute to overall better management of the preserved germplasm. Bayesian analysis of genetic structure revealed two major clusters, one containing most of the foreign cultivars, while the other consisted mainly of traditional Scandinavian cultivars, but also some very winter-hardy genotypes such as ‘Charlamovsky’, ‘Gravenstein’, ‘Transparente Blanche’, and ‘Wealthy’. Analyses of molecular variance (AMOVA) detected a signifi- cant genetic differentiation among the clusters ( fCT = 0.077; P < 0.01). The results of the Bayesian analyses do not indicate a strong differentiation between the foreign and the Norwegian apple accessions, however, they do suggest that climate adaptation has had a significant influence on the genetic structure of the preserved germplasm. Overall, apple accessions currently maintained ex situ in Norway represent a diverse germplasm which could be very valuable in future breeding programs, especially for the Scandinavian climate.
Sammendrag
Bangladesh often suffers from droughts and floods that cause substantial harm to households and communities. The frequency of such events is expected to increase with climate change. Assessing the vulnerability to climate change is a promising evaluation tool that can assist in identifying and improving adaptation strategies at various geographical scales. In this paper, we examine the vulnerability status of two regions in Bangladesh, one in the north, which is frequently impacted by severe droughts, and one in the south, which is exposed to regular flooding, high water, and salinity. We evaluate the exposure, sensitivity and adaptive capacity of each region using demographic, agro-economic, infrastructural, and biophysical indicators. We consider information obtained in a literature review, interviews with local experts, household surveys, and field visits in the study areas. We use principal components analysis to assess vulnerability to climate change between and within the north and south regions. The flood-prone, saline region in the south appears less vulnerable to climate change the northern drought prone areas, although further validation is needed.
Sammendrag
Important losses in strawberry production are often caused by the oomycete Phytophthora cactorum, the causal agent of crown rot. However, very limited studies at molecular levels exist of the mechanisms related to strawberry resistance against this pathogen. To begin to rectify this situation, a PCR-based approach (NBS profiling) was used to isolate strawberry resistance gene analogs (RGAs) with altered expression in response to P. cactorum during a time course (2, 4, 6, 24, 48, 96 and 192 h post-infection). Twenty-three distinct RGA fragments of the NB-LRR type were identified from a resistance genotype (Bukammen) of the wild species Fragaria vesca. The gene transcriptional profiles after infection showed that the response of most RGAs was quicker and stronger in the resistance genotype (Bukammen) than in the susceptible one (FDP821) during the early infection stage. The transcriptional patterns of one RGA (RGA109) were further monitored and compared during the P. cactorum infection of two pairs of resistant and susceptible genotype combinations (Bukammen/FDP821 and FDR1218/1603). The 5′ end sequence was cloned, and its putative protein was characteristic of NBS-LRR R protein. Our results yielded a first insight into the strawberry RGAs responding to P. cactorum infection at molecular level.
Sammendrag
Accessibility is a central issue for human activity, particularly in mountain areas. We investigate changes in physical accessibility in a Western Norwegian mountain area during the past 40–60 years and identify driving forces of changes. Changes in accessibility were measured as changes in travel time between permanently and seasonally inhabited farmsteads. Additionally, travel time from new access points in the mountains was calculated. C.75% of the investigated access routes to seasonal farmsteads have remained unchanged due to continued use or maintenance work, or been slightly improved due to development of paths into roads. In addition, new access routes have emerged as a result of road construction. Regrowth of paths due to abandonment of seasonal farming has reduced accessibility. Changes in accessibility have led to a concentration of activities in more easily accessibly parts of the study area. Documented changes in accessibility result from a complex interaction of driving forces that initiate or influence change. Important drivers interacting with road construction and abandonment of seasonal farming can be categorized as socio-economic, political and technological. However, the importance of culturally rooted commitment of local people or a small number of enthusiasts must not be underestimated.
Forfattere
Juliet Biira Jens Leth Hougaard Mogens LundSammendrag
Denmark is one of the EU countries with a highly recognised agricultural sector, a high level of animal health and one of the lowest medication usages. In this article we aim to provide an overview of both private and public animal health incentives nested in the cattle and pig production industry that influence the decisions and behaviours of farmers in prevention of livestock disease epidemics. Not only do individual Danish pig and cattle farmers aim at highly efficient animal production, they are also involved in collective marketing and contracting which can enhance social capital, peer pressure and instill a greater sense of ownership of disease control prevention. Public incentives including rules on how animals should be transported within Denmark, SPF certification requirements and rules on farm biosecurity further improve farmer incentives to prevent animal diseases. However, Danish pig and cattle farmers’ incentives could be further improved by specifying consequences for not following requirements such as failure to make a compulsory biosecurity plan. The relatively high compensation in case of a disease outbreak provides a safety net for farmers, encourages them to quickly report suspected notifiable diseases but it could also reduce incentives for disease prevention due to the relatively high amounts of compensation.
Forfattere
Johanna Gottschamel Andreas G. Lössl Stephanie Ruf Yanliang Wang Morten Skaugen Ralph Bock Jihong Liu ClarkeSammendrag
Abstract Dengue fever is a disease in many parts of the tropics and subtropics and about half the world’s popula- tion is at risk of infection according to the World Health Organization. Dengue is caused by any of the four related dengue virus serotypes DEN-1, -2, -3 and -4, which are transmitted to people by Aedes aegypti mosquitoes. Cur- rently there is only one vaccine (DengvaxiaÒ) available (limited to a few countries) on the market since 2015 after half a century’s intensive efforts. Affordable and accessible vaccines against dengue are hence still urgently needed. The dengue envelop protein domain III (EDIII), which is capable of eliciting serotype-specific neutralizing antibod- ies, has become the focus for subunit vaccine development. To contribute to the development of an accessible and affordable dengue vaccine, in the current study we have used plant-based vaccine production systems to generate a dengue subunit vaccine candidate in tobacco. Chloroplast genome engineering was applied to express serotype- specific recombinant EDIII proteins in tobacco chloroplasts using both constitutive and ethanol-inducible expression systems. Expression of a tetravalent antigen fusion con- struct combining EDIII polypeptides from all four ser- otypes was also attempted. Transplastomic EDIII- expressing tobacco lines were obtained and homoplasmy was verified by Southern blot analysis. Northern blot analyses showed expression of EDIII antigen-encoding genes. EDIII protein accumulation levels varied for the different recombinant EDIII proteins and the different expression systems, and reached between 0.8 and 1.6 % of total cellular protein. Our study demonstrates the suitability of the chloroplast compartment as a production site for an EDIII-based vaccine candidate against dengue fever and presents a GatewayÒ plastid transformation vector for inducible transgene expression.
Sammendrag
Berry yield and chemical composition of four commercial black currant cultivars were recorded in a field experiment in Norway over an 8-year period and related by linear regression analysis to temperature and precipitation conditions prevailing during the May-July preharvest period. Highly significant differences between cultivars and among years were found for all measured parameters. Fruit dry matter, soluble solids and pH were positively correlated with temperature and negatively correlated with precipitation during May-July, while yield, berry weight, and the concentration of total phenols and ascorbic acid showed the opposite relationship, being highly negatively correlated with temperature and positively correlated with precipitation. Similar black currant experiments elsewhere in Europe have often given deviating results, varying from opposite to no effects of the same weather variables, suggesting that fruit composition is influenced by several interacting genetic and environmental parameters. We conclude that differences in local weather and soil conditions and the use of different cultivars complicate direct comparison of such field experiments. Nevertheless, the observed strong and opposite correlations with precipitation and temperature suggest an inherently low drought tolerance of black currant plants.