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.
2012
Abstract
Light-emitting diodes (LEDs), high-pressure sodium lamps (HPSLs) and some cladding materials offer possibilities of influencing arthropod integrated pest management in greenhouse crops where light quality, quantity and photoperiod differ from nature. Light intensity, photoperiod and wavelength distribution affect plant functions and quality which, in turn, can be reflected in the performance of herbivores. The attenuation of UV-light in HPSL spectrum and in the natural winter daylight of northern latitudes may make plants more vulnerable to pests, whereas the high ratio of red to far-red of HPSLs may act to compensate for the effects of attenuated UV-levels. High red to far red ratio has been shown to result in increased production of plant phenolics and physical defences such as leaf toughness, which, in turn, can negatively influence the performance of some herbivore guilds on plants. Specific spectra produced by LEDs can influence plant quality and hence herbivore performance, but direct effects on arthropods can be even more pronounced, such as the inability to visually locat host plants in red and blue lights. Other direct effects of artificial light on pests and beneficial organisms include the detrimental effect of UV-C and UV-B on arthropods, diapause prevention by species-specific wavelengths or photoperiods, attraction to yellow-green and polarized light, reduced visibility of host or prey, and changes in take-off behaviour. Other effects include response to light intensity, interactive effects of light quality and photoperiod on fecundity, and species-specific effects of continuous light on the population growth of arthropods and plant-infesting fungi as well as the rhythmic expression of xenobiotic metabolising genes in arthropods. The potential of using the knowledge of photobiology and visual ecology of organisms for plant protection are discussed using whiteflies and fungal diseases of plants as the model species.
Abstract
No abstract has been registered
Authors
Gage Koehler Robert Wilson John V. Goodpaster Anita Sønsteby Xianyin Lai Frank A. Witzmann Jin-Sam You Jens Rohloff Stephen K, Randall Muath Alsheikh-YousefAbstract
To gain insight into the molecular basis contributing to overwintering hardiness, a comprehensive proteomic analysis comparing crowns of Fragaria × ananassa (octoploid strawberry) cultivars that differ in freezing tolerance was conducted. Four cultivars were examined for freeze tolerance and the most cold-tolerant cultivar (‘Jonsok’) and least tolerant cultivar (‘Frida’) were compared with a goal to reveal how freezing tolerance is achieved in this distinctive overwintering structure and to identify potential cold-tolerance associated biomarkers. Supported by univariate and multivariate analysis, a total of 63 spots from 2DE analysis and 135 proteins from label-free quantitative proteomics (LFQP) were identified as significantly differentially expressed in crown tissue from the two strawberry cultivars exposed to 0, 2, and 42 day cold treatment. Proteins identified as cold tolerance associated included molecular chaperones, antioxidants/detoxifying enzymes, metabolic enzymes, pathogenesis related proteins and flavonoid pathway proteins. A number of proteins were newly identified as associated with cold tolerance. Distinctive mechanisms for cold tolerance were characterized for two cultivars. In particular, the ‘Frida’ cold response emphasized proteins specific to flavonoid biosynthesis, while the more freezing tolerant ‘Jonsok’ had a more comprehensive suite of known stress responsive proteins including those involved in antioxidation, detoxification, and disease resistance. The molecular basis for ‘Jonsok’ enhanced cold tolerance can be explained by the constitutive level of a number of proteins that provide a physiological stress-tolerant “poise”.
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No abstract has been registered
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No abstract has been registered
Authors
Maria HerreroAbstract
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Authors
Isabella Børja Jan Svtlík Toril Drabløs Eldhuset Holger Lange Frank Newell Kidder Douglas Lawrence GodboldAbstract
No abstract has been registered
Abstract
1. Neodiprion sertifer nucleopolyhedrovirus (NeseNPV) is widely used as a viral bio-insecticide against larvae of the European pine sawfly N. sertifer (Geoff.) (Hymenoptera: Diprionidae), which is one of the most harmful defoliators of pines in Northern Europe. A major obstacle to studying this pathogenic virus in nature is the difficulty of confirming and quantifying the presence of NeseNPV. 2. In the present study, we developed real-time polymerase chain reaction (PCR) primers, based on the caspid gene 39 sequence, for the specific and quantitative detection of NeseNPV. The quantitative real-time PCR (qPCR) assay can detect virus from any substrate tested, including different insect life stages (egg, larval, adult), pine foliage, and litter or ground vegetation. The reproducible detection limit for the real-time assay is 0.013 pg of viral DNA (0.013 × 10−12 g), corresponding to 136 viral genomes or approximately one to seven virus occlusion bodies per sample. 3. qPCR is a specific, quantitative, sensitive, reliable and flexible procedure, and is a good supplement to conventional microscopy- or bioassay-based methods for detection of the virus. We have used qPCR to quantify the level of NeseNPV in samples collected in the field after aerial application of the virus, and demonstrated significantly higher virus levels in sawfly larvae from sprayed areas compared with unsprayed control areas 4 weeks after spraying. 4. This qPCR assay can be used to determine important aspects of the biology of NeseNPV (e.g. virus levels in different insect life stages and in their microhabitats on pine foliage and in forest litter).
Authors
Sarah Hale Johannes Lehmann David Rutherford Andrew R. Zimmerman Robert T. Bachmann Victor Shitumbanuma Adam O´Toole Kristina L. Sundqvist Hans Peter Arp Gerard CornelissenAbstract
Biochar soil amendment is advocated to mitigate climate change and improve soil fertility. A concern though, is that during biochar preparation PAHs and dioxins are likely formed. These contaminants can possibly be present in the biochar matrix and even bioavailable to exposed organisms. Here we quantify total and bioavailable PAHs and dioxins in a suite of over 50 biochars produced via slow pyrolysis between 250 and 900 °C, using various methods and biomass from tropical, boreal, and temperate areas. These slow pyrolysis biochars, which can be produced locally on farms with minimum resources, are also compared to biochar produced using the industrial methods of fast pyrolysis and gasification. Total concentrations were measured with a Soxhlet extraction and bioavailable concentrations were measured with polyoxymethylene passive samplers. Total PAH concentrations ranged from 0.07 μg g–1 to 3.27 μg g–1 for the slow pyrolysis biochars and were dependent on biomass source, pyrolysis temperature, and time. With increasing pyrolysis time and temperature, PAH concentrations generally decreased. These total concentrations were below existing environmental quality standards for concentrations of PAHs in soils. Total PAH concentrations in the fast pyrolysis and gasification biochar were 0.3 μg g–1 and 45 μg g–1, respectively, with maximum levels exceeding some quality standards. Concentrations of bioavailable PAHs in slow pyrolysis biochars ranged from 0.17 ng L–1 to 10.0 ng L–1which is lower than concentrations reported for relatively clean urban sediments. The gasification produced biochar sample had the highest bioavailable concentration (162 ± 71 ng L–1). Total dioxin concentrations were low (up to 92 pg g–1) and bioavailable concentrations were below the analytical limit of detection. No clear pattern of how strongly PAHs were bound to different biochars was found based on the biochars’ physicochemical properties.
Authors
Ricardo HolgadoAbstract
No abstract has been registered