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.
2026
Abstract
Honey can be contaminated by various natural and anthropogenic substances, posing a health risk to consumers. Pyrrolizidine alkaloids (PAs) are naturally toxic compounds many plant species produce to protect against herbivores. Honey may become contaminated if bees collect nectar and pollen from PA-producing plants. Clopyralid is the active ingredient in some herbicides, including Matrigon 72 SG, approved for weed control in oilseed rape in several countries. As a systemic substance, its application before flowering may contaminate nectar, pollen, and honey. In 2023, 30 Norwegian honey samples were tested for the content of PAs and 22 other honey samples for clopyralid. Pyrrolizidine alkaloids were detected in 20 per cent of the samples, but predominantly at low levels (<12 μg kg−1). One sample contained a higher level (27.8 μg kg−1). Clopyralid was detected at levels exceeding the EU Maximum Residue Level (MRL) at the time (0.05 mg kg−1) and the current EU MRL (2024) (0.15 mg kg−1) in seven of 22 honey samples, including five honey samples produced close to clopyralid treated oilseed rape fields, one honey sample collected next to unsprayed fields, and in one sample received from a beekeeper. It was later clarified that beehives in proximity to unsprayed cropping areas with honey with a high clopyralid content also were close to conventional clopyralid-treated oilseed rape fields. The results indicate that a more extensive survey would be appropriate to evaluate whether PAs and clopyralid are a common problem in Norwegian honeybee products.
Authors
Petter Öhrn Mats Berlin Jan-Olov Weslien Malin Elfstrand Paal Krokene Anna Maria Jönsson Audrius MenkisAbstract
Background and aims Drought weakens tree defenses, predisposing Norway spruce (Picea abies) to spruce bark beetle (Ips typographus) attack. The extreme 2018 summer drought in Sweden triggered an unprecedented bark beetle outbreak. Our objective was to quantify how weather, soil moisture, and tree provenance influence Norway spruce defense capacity to a necrotrophic beetle-associated pathogen. Methods Trees at three sites in Sweden were inoculated with the phytopathogenic fungus Leptographium europhioides on four occasions during each of the 2019 and 2021 growing seasons. At each site, we inoculated spruce provenances of Swedish or East European origin, with early and late spring bud burst, respectively. Tree defense capacity, expressed as the extent of necrotic lesion formation following fungal inoculation, was used as a proxy for resistance to bark beetle attack. Results Spruce defense capacity (i.e. lesion size) differed with water availability (both precipitation and soil moisture conditions) but not with the timing of spring bud burst. There were within-season differences, with trees having less efficient defenses (producing larger lesions) in the early season (June). On intermediate soil moisture sites, lesions were larger in 2019 than in 2021. In both years, there was a significant negative correlation between lesion size and water availability in the autumn of the previous year. Conclusion Spruce defense capacity varied with local environmental conditions but not with provenance phenology. Variations between study years reflected the sensitivity of spruce defenses to climatic variability and the partial recovery of tree resistance 3 years after the 2018 drought.
Abstract
Viroids are the smallest known nucleic acid‐based infectious agents of plants and consist of single‐stranded, circular, non‐coding RNAs that can cause significant crop diseases. The potato spindle tuber viroid (PSTVd), a model Pospiviroidae member, severely impacts Solanaceous hosts like potato and tomato, causing substantial yield reductions. Its 359‐nucleotide, rod‐like genome, with five functional domains, mediates nuclear replication, systemic movement via plasmodesmata and phloem, and evasion of host RNA silencing. High mutation rates generate diverse quasi‐species, enhancing adaptability. Recent multi‐omics studies reveal PSTVd reprogramming of host transcriptomes, epigenomes, and metabolomes, disrupting defence, hormone signalling, and photosynthesis. Within the plant holobiont, PSTVd modulates interactions with viruses, notably via RNA‐directed DNA methylation, and may affect rhizosphere microbial communities indirectly via changes in host physiology, an area that remains poorly resolved. This review synthesises advances in PSTVd structure, infection mechanisms, and holobiont interactions, highlighting its role in uncovering RNA‐mediated pathogenesis principles. Key knowledge gaps persist regarding host factors facilitating systemic spread and interactions with other organisms, such as microbial communities. Ongoing PSTVd research is essential to address this gap and guide strategies for viroid‐resistant crops and sustainable control.
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Authors
Xing Wu Tatiana Bellagio Yunru Peng Lucas Czech Meixi Lin Patricia Lang Ruth Epstein Mohamed Abdelaziz Jake Alexander Carlos Alonso-Blanco Heidi Lie Andersen Modesto Berbel Joy Bergelson Oliver Bossdorf Liana Burghardt Mireille Caton-Darby Robert Colautti Carolin Delker Panayiotis G. Dimitrakopoulos Kathleen Donohue Walter Durka Gema Escribano-Avila Steven J. Franks Felix B. Fritschi Alexandros Galanidis Alfredo Garcia-Fernández Ana García-Muñoz Elena Hamann Allison Hutt José M. Iriondo Thomas E. Juenger Stephen R. Keller Karin Koehl Arthur Korte Pamela Korte Alexander Kutschera Carlos Lara-Romero Laura Leventhal Daniel Maag Arnald Marcer Martí March-Salas Juliette de Meaux Belén Méndez-Vigo Javier Morente-López Timothy C. Morton Zuzana Münzbergova Anne Muola Hanna Akiko Nomoto Meelis Pärtel F. Xavier Picó Brandie Quarles-Chidyagwai Marcel Quint Niklas Reichelt Agnieszka Rudak Johanna Schmitt Gregor Schmitz Merav Seifan Basten L. Snoek Remco Stam Marc Stift John R. Stinchcombe Mark A. Taylor Peter Tiffin Irène Till-Bottraud Anna Traveset Jean-Gabriel Valay Martijn Van Zanten Vigdis Vandvik Cyrille Violle Detlef Weigel Maciej Wódkiewicz François Vasseur J. F. Scheepens Moises Exposito-AlonsoAbstract
Climate change forces species to adapt rapidly to avoid extinction. To directly observe rapid adaptation and extinction, we conducted synchronized evolution experiments with Arabidopsis thaliana in 30 locations across Western Europe, the Mediterranean, the Levant, and North America. Whole-genome pooled sequencing of ~70,000 surviving plants revealed repeatable allele frequency shifts in similar climates but divergent shifts across contrasting ones, indicating evolutionary adaptation. We identified genetic variants linked to climate adaptation, including genes involved in processes ranging from thermal-stress sensing to spring-flowering timing. Evolutionary trends were often predictable, but variable, across environments. In warmer climates, evolutionary predictability correlated with population survival over 5 years, whereas erratic changes preceded extinction. These results show that rapid climate adaptation is possible, but understanding its limits will be crucial for biodiversity forecasting.
Authors
Lumbani Benedicto Banda Frank Thomas Ndjomatchoua Ritter Atoundem Guimapi Komi Mensah Agboka Abdelmutalab G.A. Azrag Wezi G. Mhango Trust Kasambala Donga Chikondi Makwiza Karl Thunes Elfatih M. Abdel-RahmanAbstract
The cassava whitefly (Bemisia tabaci) greatly constrains cassava production across Africa due to its role as a vector of viral diseases that cause substantial yield losses. Effective management of this insect pest requires detailed knowledge of its spatio-temporal distribution, however long-term datasets are scarce. Mechanistic models circumvent these long-term data needs by modelling temperature-dependent processes that govern population dynamics. Nevertheless, their application to B. tabaci remains poorly explored. Here, we developed a mechanistic model to derive a risk index (RI) for B. tabaci across Africa, focusing on Malawi. The model integrates the effects of temperature on the life stages of B. tabaci to predict temporal risk dynamics and assess climate change impacts. Validation against historical data demonstrated strong agreement, with high cosine similarity values (0.95 in 1988 and 0.96 in 1990) and high correlation coefficients (0.73 and 0.78 in 1988 and 1990, respectively), supporting its suitability as a proxy for whitefly population dynamics. Areas with temperatures between 20.2 °C and 32.5 °C are conducive to B. tabaci population increase, with suitability peaking near 27.5 °C. Cassava-growing regions in central and western Africa experience year-round higher RI values, whereas southeastern Africa experiences peak RI values from October to March. In Malawi, the lakeshore and southern regions were most vulnerable, with RI peaking in these areas during the rainy season. At continental and national scales, climate change is projected to increase RI values. These findings underscore the importance of timing pest control interventions to align with peak risk periods and highlight the utility of mechanistic models for informing region-specific whitefly management strategies.
Authors
Mandeep PoudelAbstract
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Authors
Therese With BergeAbstract
Presentasjon på oppstartsmøte 13.2.2026