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.
2017
Abstract
Volatiles emitted by plants convey an array of information through different trophic levels. Animals such as host-seeking herbivores encounter plumes with filaments from both host and non-host plants. While studies showed a behavioral effect of non-host plants on herbivore host location, less information is available on how a searching insect herbivore perceives and flies upwind to a host-plant odor plume within a background of non-host volatiles. We hypothesized here that herbivorous insects in search of a host-plant can discriminate plumes of host and non-host plants and that the taxonomic relatedness of the non-host have an effect on finding the host. We also predicted that the ratio between certain plant volatiles is cognized as host-plant recognition cue by a receiver herbivorous insect. To verify these hypotheses we measured the wind tunnel response of the moth Argyresthia conjugella to the host plant rowan, to non-host plants taxonomically related (Rosaceae, apple and pear) or unrelated to the host (Pinaceae, spruce) and to binary combination of host and non-host plants. Volatiles were collected from all plant combinations and delivered to the test insect via an ultrasonic sprayer as an artificial plume. While the response to the rowan as a plant was not affected by the addition of any of the non-host plants, the attraction to the corresponding sprayed headspace decreased when pear or apple but not spruce were added to rowan. A similar result was measured toward the odor exiting a jar where freshly cut plant material of apple or pear or spruce was intermixed with rowan. Dose-response gas-chromatography coupled to electroantennography revealed the presence of seven field attractive and seven background non-attractive antennally active compounds. Although the abundance of field attractive and of some background volatiles decreased in all dual combinations in comparison with rowan alone, an increased amount of the background compounds (3E)-4,8-Dimethyl-1,3,7-nonatriene ((E)-DMNT) and (Z)-3-hexenyl acetate was found in the rowan-apple and rowan-pear but not in the rowan-spruce headspace. A higher ratio between the abundance of each field attractive component and that of (E)-DMNT and (Z)-3-hexenyl acetate was measured for rowan and rowan-spruce in contrast to rowan-pear and rowan-apple headspaces. Our result suggests that the ratio between field attractive and background antennaly active volatiles encodes host-plant recognition in our study system.
Abstract
Sewage sludge is an important amendment that enriches soils with organic matter and provides plants with nutrients such asnitrogenandphosphorus.However,knowledgeonthe fateandeffectsof organic pollutants presentin the sludge on soilorganisms is limited.In the present study, the uptake of triclosan, galaxolide, and tonalide in the earthworm Dendrobaena veneta was measured 1 wk afteramendment of agricultural soil with sewage sludge, while elimination kinetics were assessed over a 21-d period after transferring worms toclean soil. After 1-wk exposure, earthworms had accumulated 2.6 0.6 mgg1galaxolide, 0.04 0.02 mgg1tonalide, and0.6 0.2 mgg1triclosan. Both synthetic musks were efficiently excreted and below the limit of quantification after 3 and 14 d ofdepuration for tonalide and galaxolide, respectively. Triclosan concentrations, on the other hand, did not decrease significantly over thedepuration period, which may lead to the transfer of triclosan in the food web.
Abstract
No abstract has been registered
2016
Authors
Knut Erik Tollefsen Kine Bæk Ana Almeida Linn Anette Haug Hans Ragnar Norli Sven R. Odenmarck Marianne StenrødAbstract
This project evaluated whether the principles of combined toxicity assessment (CTA) and cumulative risk assessment (CRA) can be used to predict the toxicity of ecologically-relevant mixtures of plant protection products (PPPs) in surface waters receiving run-off from Norwegian agricultural areas. A combination of testing solid phase extracts (SPE), whole surface water and a synthetic mixture in an algal bioassay and predicting combined toxicity using CTA models were conducted on selected samples from the Heia catchment (Råde, Norway). The results demonstrated that designing and testing synthetic mixtures on the basis of measured concentrations of PPPs was the best method for the accurate determination of combined toxicity due to confounding factors introduced by whole water and SPE testing. Combined toxicity models based on Concentration Addition (CA) successfully predicted the toxicity of the complex synthetic mixture and verified that a mixture of PPPs acted in an additive manner. Tiered assessment of the cumulative risk of active PPP substances and PPP formulations proposed by the European Food Safety Authority (EFSA) were considered applicable also for the CRA of complex environmental mixtures and could potentially aid the identification of relevant mixtures, risk drivers and susceptible species as input to the assessment and approval of PPPs.
Authors
Marit Almvik Marianne Stenrød Ole Martin Eklo Nina Holteberg Paulien Jakobje Mulder Roger Holten Roger RosethAbstract
No abstract has been registered
Authors
Marit AlmvikAbstract
No abstract has been registered
Authors
Marianne Stenrød Marit Almvik Ole Martin Eklo Anne Louise Gimsing Roger Holten Kai Künnis-Beres Mats Larsbo Linas Putelis Katri Siimes Inara Turka Jaana Uusi-KämppäAbstract
No abstract has been registered
Abstract
Nonylphenols (NP) are a group of alkylphenols, formed upon degradation of nonylphenol ethoxylates such as nonylphenol monoethoxylate (NP1EO) or nonylphenol diethoxylate (NP2EO), which have been broadly used as non-ionic surfactants. Both NP and their ethoxylates are often present in the sewage, despite being banned and substituted by less toxic alcohol ethoxylates in many countries. There is a number of degradation studies of nonylphenol in the soil environment, but there is a lack of understanding on how plants and soil organisms such as earthworms can affect the degradation. In our study, we investigated the degradation of 4-nonylphenol (4-NP) in a mineral field soil in the presence of barley (Hordeum vulgare) and earthworms (Aporrectodea caliginosa). Soil was spiked with 4-NP at a concentration of 12.5 mg kg-1 d.w. soil. Results showed that the degradation of 4-NP in soil was rapid during the 28 days after spiking, with remaining concentration of 0.397 mg kg-1 d.w. soil on day 28. Degradation was much slower between days 28 and 120, with a remaining concentration of 0.214 mg kg-1 d.w. soil on day 120. No significant difference in the degradation of 4-NP in the presence of either plants or worms was observed, but sampling after 28 days of exposure revealed transfer of 4-NP to worms (worm tissue concentration = 0.79 μg g-1), which increased with time (1.66 μg g-1 after 120 d). The calculated transfer factor after 28 (TF28) and 120 days (TF120) was 0.07 and 0.13 respectively. No toxicity or accumulation in plants was observed at the concentration tested herein. Concentration of 4-NP in the rhizosphere was not statistically different from that in the bulk soil.
2015
Abstract
No abstract has been registered
Authors
Marit Almvik Randi Bolli Agnethe Christiansen Ole Martin Eklo Roger Holten Paulien Jakobje Mulder Gunvor SennesetAbstract
No abstract has been registered