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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.

2018

Abstract

When ground level photography is to be used in landscape monitoring, it is important to record when, where, how and possibly even why the photographs are taken. Standardisation enables better repeat photography in the future and maximises comparability of photos over time. We used a Cultural Environment protected by law on the peninsula of Bygdøy,Oslo municipality, as a study area to document advantages and disadvantages of different approaches to the first round of landscape photography for long-term monitoring.

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Abstract

Phytophthora cryptogea, P. gonapodyides, P. lacustris, P. megasperma, P. plurivora, P. taxon paludosa and an unknown Phytophthora species were isolated from waterways and soil samples in Christmas tree fields in southern Sweden. In addition, P. megasperma was isolated from a diseased Norway spruce (Picea abies) plant from one of the fields in Svalöv. Inoculation tests were sequentially carried out with one isolate from each of the three species P. cryptogea, P. megasperma, and P. plurivora, all known pathogens on conifers. The same three isolates were used to study a few morphological features to confirm the identification, and temperature-growth relationships were carried out to see how well the organisms fit into Swedish climatic conditions. Seedlings of Norway spruce and Nordmann fir (Abies nordmanniana) were inoculated in the roots and the stems. None of the isolates caused extensive root rot under the experimental conditions, but all three species could be re-isolated from both Norway spruce and Nordmann fir. Phytophthora root rot is currently of minor concern for Christmas tree growers in Sweden. However, the Phytophthora isolations from soil and water indicate the presence of this damaging agent, which may lead to future problems.

Abstract

Plants are exposed to various pathogens in their environment and have developed immune systems with multiple layers of defence to fight-back. However, often pathogens overcome the resistance barriers, infect the plants to cause the disease. Pathogens that cause diseases on economically important crop plants like strawberry incur huge losses to the agriculture industry. For example, The 2016 outbreak of strawberry grey mould (Botrytis cinerea) in Norway caused up to 95% crop losses. Outbreaks like this underline the importance of developing novel and sustainable tools to combat plant diseases, for example by increasing the plants’ natural disease resistance. Priming plant defences using chemical elicitors may be effective in providing the enhanced resistance against multiple pathogens. We have used β-aminobutyric acid (BABA) as a chemical priming agent to induce resistance in Fragaria vesca against Botrytis cinerea. Effects of BABA on disease progression and defence responses of Fragaria are being characterized using molecular tools like RNAseq, RT-PCR and ChIP. As priming chemicals may induce an epigenetic memory in treated plants, we also plan to study the histone methylation patterns in primed plants and the genes that are regulated. Our long-term aim is to understand the duration of the epigenetic memory and its cross-generational transmission to the progeny in Fragaria. Our results will help guide various crop protection strategies in addition to providing new insights to develop novel tools for plant disease management.

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Abstract

Four lab scale biogas reactors fed with a substrate composition of ensiled fish waste and manure fixed at 13 and 87 vol %, respectively, were operated with HRTs of 20, 25, 30 and 40 days. Biogas process performance and stability were evaluated with regard to CH4 yields, NH4+ accumulation and abundance of NH4+-tolerant microorganisms. Process performance in the reactors operated at different HRTs were compared to process performance in reactors operated with constant HRT, fed with increased ratios of fish waste. The process performance and microbial dynamics were stable in reactors operated at constant amount of fish waste in the feed and with different HRTs. In the reactors added elevated ratios of fish waste, the concentration of NH4+ and abundance of NH4+-tolerant acetate oxidizing bacteria increased. The biogas process failed in these reactors simultaneously with an observed shift in microbial composition. In particular, the bacterium Tepidanaerobacter Acetatoxydans seemed to affect the biogas process stability. The hydrogenotrophic Methanomicrobiales increased in abundance in response to higher fish waste loading and NH4+ concentrations. This study showed that at a loading of 13% fish waste, it is possible to decrease the HRT from 30 to 20 days without markedly inhibiting the process stability.