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.
2025
Forfattere
Mikarlsen, NoraSammendrag
Pest control is a central part of modern strawberry farming. Spider mites are one of the most common pests in strawberries, and can cause significant reduction in yield. In order to properly manage and control spider mite populations, early detection is crucial. This thesis sets out to detect two-spotted spider mites (TSSM) in strawberries using hyperspectral imaging (HSI). A variety of methods have explored including visual inspection of the spectrum and its derivatives, as well as the use of vegetation indices (VIs). In addition, this thesis also explores machine learning (ML) and deep learning (DL) for early detection of TSSM. The mean spectrum from the images was used for classification in combination with Linear Discriminant Analysis (LDA) and Random Forest Classifier. Two separate Random Forest models were trained, one that distinguished between control, drought, and mite-infested strawberry plants, and one five-class with three different infestation levels, in addition to control and drought group. The three-class model achieved an F1-score of 0.86, while the five-class model had an F1-score of 0.845. The images themselves were used for classification by a ResNet18 model. The model was trained for each imaging day separately, and achieved accuracies in the range of 0.7-0.9 and F1-scores between 0.709-0.903. The work presented in this thesis highlights the capabilities of HSI in combination with ML and DL for early detection of TSSM in strawberries.
Forfattere
Ivan M De-la-Cruz Femke Batsleer Dries Bonte Carolina Diller José Luis Izquierdo Sonja Still Sonia Osorio David Posé Aurora de la Rosa Martijn L. Vandegehuchte Anne Muola Timo Hytönen Johan A StenbergSammendrag
Climate change creates novel environmental conditions that plant species must adapt to. Since plants are finely tuned to the seasonality of their environments, shifts in their phenology serve as some of the most compelling evidence of climate change’s impact. Understanding how key fitness-related phenological traits, such as flowering onset, respond to novel environments is crucial for assessing species’ plasticity and/or adaptive potential under climate change. Here, we investigated the onset of flowering in Fragaria vesca (woodland strawberry; Rosaceae) by translocating genotypes between four sites along a south–north gradient in Europe, encompassing its entire latitudinal distribution range with varying temperatures, precipitation patterns, and photoperiods. At each site, we included a reduced precipitation treatment using rainout shelters to simulate drought conditions and assess their impact on flowering onset. Our findings revealed that southern and central European genotypes exhibited a delayed onset of flowering when translocated to the northernmost site. In contrast, no difference among genotypes was found in the onset of flowering when grown in more southerly sites. Reduced precipitation accelerated flowering across several sites and all genotypes, irrespective of their latitudinal origin. Overall, northern European genotypes showed a greater capacity to adjust their onset of flowering in response to the different photoperiods and temperatures across the latitudinal gradient compared to southern European genotypes, suggesting that they may be more resilient to shifting environmental conditions. Differences in phenotypic plasticity among genotypes translocated to higher versus lower latitudes highlight the role of photoperiod in evaluating a species’ capacity to cope with climate change.
Sammendrag
Methyl jasmonate (MeJA) is known to effectively protect Norway spruce (Picea abies) against pests and pathogens. However, MeJA application to spruce saplings can significantly reduce growth and is not feasible to use in protecting older trees due to cost. Seed treatment with MeJA or other priming stimulants with fewer negatives could be a practical solution to enhance Norway spruce resistance. Therefore, we assessed the potential of Norway spruce seed treatment with MeJA, pipecolic acid (PipA), lignan (Li), and chitosan (Chi) in enhancing the resistance of the emerged seedlings against Botrytis cinerea. For the first time, MeJA seed treatment was shown to reduce the mortality of the seedlings effectively after B. cinerea infection, with a growth reduction as a side effect. To understand the mechanisms underlying this phenomenon, we quantified phenolics, defense hormones, and differential transcript expressions. MeJA seed treatment increased the concentration of the flavan-3-ols catechin and proanthocyanidin B1. Transcriptomic data suggested an increase in oxidative stress protection, cell wall reinforcement, and pathogenesis-related protein production. Our data also suggested an antagonistic relationship in hormonal signaling between abscisic acid (ABA) and jasmonic acid (JA)/ethylene (ET). Overall, our findings indicated MeJA seed treatment enhanced resistance of young seedlings against B. cinerea via a multitude of defense responses, modulated by complex regulatory systems.
Forfattere
Alexey Mikaberidze C. D. Cruz Ayalsew Zerihun Abel Barreto Pieter Simon A Beck Rocío Calderón Carlos Camino Rebecca E. Campbell Stephanie K.L. Delalieux Frédéric Fabre Elin Falla Stuart Fraser Kaitlin M. Gold Carlos Gongora-Canul Frédéric Hamelin Dalphy Ondine Camira Harteveld Cheng Fang Hong Melen Leclerc Da Young Lee Murillo Lobo Anne Katrin Mahlein Emily McLay Paul Melloy Stephen Parnell Uwe Rascher Jack Rich Irene Salotti Samuel Soubeyrand Susan Sprague Antony Surano Sandhya D. Takooree Thomas H. Taylor Suzanne Touzeau Pablo J. Zarco-Tejada Nik J. CunniffeSammendrag
Plant diseases impair the yield and quality of crops and threaten the health of natural plant communities. Epidemiological models can predict diseaseand inform management. However, data are scarce, because traditional methods to measure plant diseases are resource intensive, which often limitsmodel performance. Optical sensing offers a methodology to acquire detailed data on plant diseases across various spatial and temporal scales. Keytechnologies include multispectral, hyperspectral, and thermal imaging, as well as light detection and ranging; the associated sensors can be installedon ground-based platforms, uncrewed aerial vehicles, airplanes, and satellites. However, despite enormous potential for synergy, optical sensing andepidemiological modeling have rarely been integrated. To address this gap, we first review the state of the art to develop a common language accessibleto both research communities. We then explore the opportunities and challenges in combining optical sensing with epidemiological modeling. Wediscuss how optical sensing can inform epidemiological modeling by improving model selection and parameterization and providing accurate maps ofhost plants. Epidemiological modeling can inform optical sensing by boosting measurement accuracy, improving data interpretation, and optimizingsensor deployment. We consider outstanding challenges in (A) identifying particular diseases; (B) data availability, quality, and resolution; (C) linkingoptical sensing and epidemiological modeling; and (D) emerging diseases. We conclude with recommendations to motivate and shape research andpractice in both fields. Among other suggestions, we propose standardizing methods and protocols for optical sensing of plant health and developingopen access databases including both optical sensing data and epidemiological models to foster cross-disciplinary work.
Forfattere
Maxime Eeraerts Julia Osterman Péter Batáry Alexandra Maria Klein Matthias Albrecht Georg K.S. Andersson András Báldi Olivia M. Bernauer Leah Blechschmidt Eleanor J. Blitzer Paulo A.V. Borges Jordi Bosch Katherine L.W. Burns Alistair J. Campbell Sílvia Castro James M. Cook Robin Daelemans Bryan N. Danforth Arjen G. de Groot Kinley Dorji Rita Földesi Hannah R. Gaines Day Daniel García Lucas A. Garibaldi Michael P.D. Garratt Andrew Gonzalez Heather Grab Claudio Gratton Maren Kristine Koffeld Halvorsen Peter A. Hambäck Bjørn Arild Hatteland Olivier Honnay Eva Hulsmans Sandra Kaasen Vestheim David Kleijn Anikó Kovács-Hostyánszki Martin J. Lechowicz Nicolas Leclercq Yunhui Liu João Loureiro Rachel E. Mallinger Leon Marshall Ivan Meeus Marcos Miñarro Diego N. Nabaes Jodar Adara Pardo Mia G. Park Robert J. Paxton Néstor Pérez-Méndez Rafael A. Pincante De Carvalho Paavo Pirttilehto Matti Pisman Simon G. Potts Nigel E. Raine James R. Reilly Laura Roquer-Beni Ulrika Samnegård Dara A. Stanley Louis Sutter Kyle Teixeira-Martins Simon M. Tierney Ruan Veldtman Nicolas J. Vereecken Felix Wäckers Timothy Weekers Julianna K. Wilson Panlong Wu Kris VerheyenSammendrag
1. Apple is one of the most important pollinator-dependent fruit crops worldwide. To secure high-quality yields, it is crucial to know which, and to what extent, pollinating insects contribute to its pollination success as measured by fruit set, fruit weight and seed set. 2. We perform a meta-analysis of field studies conducted across multiple orchards on insect-mediated pollination in apple cultivation, using raw data from 29 studies, totalling 532 orchard replicates. We assessed the extent of pollen limitation on different pollination outcomes and assessed the contribution of honeybees, wild bees and bee species richness to apple pollination. 3. Across all studies, we detected strong evidence of pollen limitation for fruit set and seed set, but not for fruit weight. Honeybees were the most abundant flower visitors (average relative visitation of 71.9%) compared to wild bees; but when correcting for their pollination efficiency, the relative pollination contribution of honeybees was lower compared to their relative visitation (vice versa for solitary bees). 4. We conclude that honeybee visitation rate did not influence fruit or seed set; yet increasing honeybee visitation had a small, negative effect on fruit weight. Fruit set was not influenced by wild bee visitation rate, whereas wild bee visitation had a small, but clear positive effect on fruit weight and seed set. Bee species richness had a small, positive effect on seed set; whereas it did not affect fruit set and fruit weight. 5. Syntheses and applications. Our study highlights that pollen limitation is common in this global crop. While managed honeybees are dominant pollinators, a diverse community of wild bees contributes significantly to apple pollination and high-quality yield. The positive effect of wild bees and species richness on fruit weight and seed set demonstrates that wild bee pollination results in better-quality fruit production (increased weight & seed set). Therefore, our synthesis highlights the importance of conserving pollinator diversity to maintain pollination services. The absence of a clear effect of honeybee visitation rate on fruit and seed set, coupled with its negative impact on fruit weight, suggests a need for further optimisation of honeybee management to improve the cost-efficiency of pollination management.
Forfattere
Benedicte Riber Albrectsen Kristiina Mäkinen Lovely Mahawar Arti Mishra Isaac Kwesi Abuley Isalyne Veillon Apsara Indhu Gopan Radha Sivarajan Sajeevan Svante Resjö Erik Andreasson Erland Liljeroth Peter Marhavý Simeon Rossmann Jens Grønbech HansenSammendrag
Based on discussions within the Northern Tubers of Potato network (N’TOP-net), this review highlights northern Scandinavia’s potential for sustainable, low pest seed potato production. While long transport distances currently limit large-scale supply for consumption or processing, low pest pressure and stricter EU plant protection regulations increase its value for seed production. Climate change is expected to extend the growing season, driving renewed interest in Northern Scandinavia’s role in European food security. Finland exemplifies this potential, and parts of northern and central Sweden—historically suppliers of disease-free seed potatoes, even exported to Brazil—offer expansion opportunities. Nordic potato production, key biotic stressors, and opportunities for regional cooperation are examined, with a focus on novel farming practices, breeding innovations, and disease surveillance to improve resilience and sustainability. Despite shared values in cultivar selection, certification, and potato preferences, Nordic production strategies remain uncoordinated for long-term sustainability. We advocate for transnational, interdisciplinary collaboration to enhance Europe’s food security through joint efforts in three key areas: (1) soil-conserving farming, (2) breeding for adaptation to longer day length and resistance traits, and (3) transnational pest and disease surveillance. A Nordic potato initiative can strengthen European cooperation on sustainable production amid climate change. However, as policies must balance the benefits of longer growing seasons with emerging risks such as pests, droughts, and flooding, coordinated research, regulatory adaptation, and climate resilience investments are essential for safeguarding seed potato quality, food security, and supply chain stability.
Forfattere
Kristiina Matilda Maria Visakorpi Zafar A. Reshi Oriol Grau Anne Muola Anna Orczewska Koenraad Van Meerbeek Bente Jessen GraaeSammendrag
Invasive species are one of the greatest threats to biodiversity. However, our understanding of how these species persist and spread in novel environments remains limited. Specifically, the relative importance of species interactions versus environmental conditions and the role of rapid evolutionary adaptation are not fully understood. Here, we investigate the impact of these factors on the distribution of the invasive Himalayan balsam ( Impatiens glandulifera ). We examined whether the climatic niche of the species is pre-adapted to the environmental conditions in the introduced range through niche modeling. Field surveys were conducted to assess the importance of herbivory and competition, and greenhouse treatments were used to investigate local adaptation. We found that the species has not yet fully occupied the suitable climatic space in its introduced range in Europe. Our results suggest that the species may have experienced enemy release while also facing increased biotic pressure at the northern range edge. We identified adaptive differentiation in flowering time, which enhances reproductive success when plants grow in climates similar to their origin. Our results indicate that Himalayan balsam has rapidly adapted to differences in growing season length in its introduced range, with trait plasticity providing an adaptive advantage. Together, these findings suggest that the species may continue to spread across its introduced range in Europe.
Sammendrag
Brassica carinata is an important oil crop with significant potential for food and industrial production. The application of the CRISPR/Cas9 genome editing tool in B. c arinata could accelerate its breeding cycle. However, no efficient DNA-free gene editing method currently exists for this species. Protoplast-based CRISPR editing presents a promising solution, though it is often challenging for many crop species. In this study, we investigated several critical factors influencing in vitro shoot regeneration, including genotype, sugar type, selection and combination of plant growth regulators (PGRs), and culture duration on different media throughout various stages of protoplast development. As a result, we developed a highly efficient, five-stage protoplast regeneration protocol for B. carinata based on specific stages of protoplast development. Key findings of this study include the requirement for high concentrations of NAA and 2,4-D in the initial medium (MI) for cell wall formation, while a lower auxin concentration relative to cytokinin was necessary for active cell division (MII). For callus growth and shoot induction, a high cytokinin-to-auxin ratio was essential (MIII), and an even higher cytokinin-to-auxin ratio was optimal for shoot regeneration (MIV). For shoot elongation, low levels of BAP and GA 3 were sufficient (MV). Our results also demonstrated that the duration of culture on different media and maintaining appropriate osmotic pressure at the early stages were crucial for successful protoplast regeneration. With this optimized protocol, we achieved an average regeneration frequency of up to 64% and a transfection efficiency of 40% using the GFP marker gene. This efficient protoplast regeneration protocol is now being employed for genome editing in our lab and is expected to significantly enhance the application of the CRISPR system in both basic research and the genetic improvement of B. carinata over the long term.
Sammendrag
NoBlight-prosjektet, leia av NIBIO, har som mål å auka kunnskapen kring tørrote og tørrflekksjuke, slik at vi kan utvikla nye verktøy og strategiar for nedkjemping, og dermed redusera bruken av sprøytemiddel. Eit av delmåla i prosjektet er å kartlegga tørrote-populasjonar i Noreg og undersøkja den genetiske variasjonen innan populasjonane
Forfattere
Theresa Weigl Jorunn Børve Emily Follett Melissa Magerøy Hanne Larsen Carl Gunnar Fossdal Siv Fagertun RembergSammendrag
The effect of harvest timing on postharvest ripening was investigated by changes in ethylene production, expression of ethylene biosynthesis genes MdACS1, MdACS6, (1-aminocyclopropane-1-carboxylic acid synthase 1 and 6) and the ACS degradation promoting gene MdETO1 (Ethylene overproducer 1). Apple fruit of two cultivars, ‘Red Aroma’ and ‘Rubinstep’, were harvested at three time points, early, middle, and late, at two-week intervals. Fruit were either treated with 1 ppm 1-Methylcyclopropene (1-MCP) or remained untreated, and stored at 4 °C in regular atmosphere. Late harvested, untreated apples reached peak ethylene production after the shortest time in cold storage ('Red Aroma' in week five, 'Rubinstep' in weeks nine and ten), while early harvested, untreated fruit reached their peak after a longer time ('Red Aroma' in week eight, 'Rubinstep' in weeks 13 and 14). Early harvested fruit experienced greater firmness loss and a higher increase in SCC/TA ratio during cold storage. Senescence in late harvested, untreated fruit was evident from low ethylene production after simulated shelf-life and increased physiological disorders in ‘Rubinstep’. In 1-MCP-treated fruit, ethylene production increased toward the end of storage, particularly in early harvested fruit, indicating a decline in 1-MCP efficacy over time. Gene expression analysis showed strong induction of MdACS1 during climacteric ripening. MdETO1 positively correlated with MdACS1 gene expression, suggesting positive co-regulation. The expression of MdACS6 was negatively correlated with simulated shelf-life and with 1-MCP treatment, suggesting regulation by temperature and metabolic state. Overall, harvest timing and 1-MCP strongly influenced the changes in fruit physiology during postharvest storage.