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.
2020
Abstract
The invasive slug Arion vulgaris (Gastropoda: Arionidae) is an agricultural pest and serious nuisance in gardens of Central and Northern Europe. To investigate if the success of A.vulgaris in Norway can be attributed to a release from parasites, we compared the prevalence and parasite load of nematodes and trematodes in A. vulgaris to that of three native gastropod species, A. circumscriptus, A. fasciatus and Arianta arbustorum, in SE Norway. We found A. vulgaris to have the highest prevalence of both parasite groups (49% nematodes, 76% trematodes), which does not support the parasite release hypothesis, but rather points to A. vulgaris as a potentially important intermediate host of these parasites. For trematodes the number of individuals (parasite load) did not differ among host species; for nematodes it was higher in A. vulgaris than A. fasciatus. To further compare the parasite susceptibility of the surveyed gastropods, we exposed A. vulgaris, A. fasciatus, and A. arbustorum to a slug parasitic nematode, Phasmarhabditis hermaphrodita, in the laboratory. This nematode is commercially available and widely used to control A. vulgaris. The non-target species A. fasciatus was most affected, with 100% infection, 60% mortality and significant feeding inhibition. A. vulgaris was also 100% infected, but suffered only 20% mortality and little feeding inhibition. The load of P. hermaphrodita in infected specimens was not significantly different for the two Arion species (median: 22.5 and 45, respectively). Only 35% of A. arbustorum snails were infected, none died, and parasite load was very low (median: 2). However, they showed a near complete feeding inhibition at highest nematode dose, and avoided nematode-infested soil. Our results indicate that A. vulgaris may be less susceptible to P. hermaphrodita than the native A. fasciatus, and that non-target effects of applying this nematode in fields and gardens should be further investigated.
Authors
Carmen Morales-Rodriguez Sten Anslan Marie-Anne Auger-Rozenberg S. Augustin Yuri N. Baranchikov Amani Bellahirech Daiva Burokiene Dovilė Čepukoit Ejup Çota K Davydenko H.T. Doğmuş-Lehtijärvi R. Drenkhan T. Drenkhan Rene Eschen I. Franić M. Glavendekić MB De Groot Magdalena Kacprzyk Marc Kenis Natalia Kirichenko I. Matsiakh DL Musolin Justyna A. Nowakowska Richard O’Hanlon S. Prospero A Roques A Santini Venche Talgø Leho Tedersoo A Uimari A. Vannini J Witzell S Woodward Antonios Zambounis Michelle ClearyAbstract
No abstract has been registered
Authors
Melissa Magerøy Erik Christiansen Bo Långström Anna-Karin Borg-Karlson Halvor Solheim Niklas Björklund Tao Zhao Axel Schmidt Carl Gunnar Fossdal Paal KrokeneAbstract
Plants can form an immunological memory known as defense priming, whereby exposure to a priming stimulus enables quicker or stronger response to subsequent attack by pests and pathogens. Such priming of inducible defenses provides increased protection and reduces allocation costs of defense. Defense priming has been widely studied for short‐lived model plants such as Arabidopsis, but little is known about this phenomenon in long‐lived plants like spruce. We compared the effects of pretreatment with sublethal fungal inoculations or application of the phytohormone methyl jasmonate (MeJA) on the resistance of 48‐year‐old Norway spruce (Picea abies) trees to mass attack by a tree‐killing bark beetle beginning 35 days later. Bark beetles heavily infested and killed untreated trees but largely avoided fungus‐inoculated trees and MeJA‐treated trees. Quantification of defensive terpenes at the time of bark beetle attack showed fungal inoculation induced 91‐fold higher terpene concentrations compared with untreated trees, whereas application of MeJA did not significantly increase terpenes. These results indicate that resistance in fungus‐inoculated trees is a result of direct induction of defenses, whereas resistance in MeJA‐treated trees is due to defense priming. This work extends our knowledge of defense priming from model plants to an ecologically important tree species.
Authors
Christian PedersenAbstract
No abstract has been registered
Authors
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Karina Petersen S. Jannicke MoeAbstract
No abstract has been registered
Authors
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Karina Petersen S. Jannicke MoeAbstract
No abstract has been registered
Authors
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Roger Holten S. Jannicke MoeAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Andreas Hagenbo Yasmine Piñuela Carles Castano Juan Martınez de Aragon Sergio de-Miguel Josu G. Alday Jose Antonio BonetAbstract
* In forests, ectomycorrhizal mycelium is pivotal for driving soil carbon and nutrient cycles, but how ectomycorrhizal mycelial dynamics vary in ecosystems with drought periods is unknown. We quantified the production and turnover of mycorrhizal mycelium in Mediterranean Pinus pinaster, Pinus sylvestris and Quercus ilex forests and related the estimates to standardised precipitation index (SPI), to study how mycelial dynamics relates to tree species and drought‐moisture conditions. * Production and turnover of mycelium was estimated between July and February, by quantifying the fungal biomass (ergosterol) in ingrowth mesh bags and using statistical modelling. SPI for time scales of 1–3 months was calculated from precipitation records and precipitation data over the study period. * Forests dominated by Pinus trees displayed higher biomass but were seasonally more variable, as opposed to Q. ilex forests where the mycelial biomass remained lower and stable over the season. Production and turnover, respectively, varied between 1.4–5.9 kg ha−1 d−1 and 7.2–9.9 times yr−1 over the different forest types and were positively correlated with 2‐month and 3‐month SPI over the study period. * Our results demonstrated that mycorrhizal mycelial biomass varied with season and tree species and we speculate that production and turnover are related to physiology and plant host performance during drought.
Abstract
No abstract has been registered