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.
2009
Authors
Dana Daniela Maria Soare Daniela Stefanescu Valentina Cotet Tore Krogstad Marianne Bechmann Florin Oancea Carmen Lupu Florentin ChitoranAbstract
No abstract has been registered
Authors
Håkan Broman Mikael Frisk Mikael RönnqvistAbstract
No abstract has been registered
Authors
Lone Ross GobakkenAbstract
Mould growth on exterior coated cladding façades is an undesirable element; it is considered to be major maintenance concern and will often shorten the aesthetical service life of the façade. On the other hand, rapid colonisation and colour change of unpainted wooden claddings is often anticipated and used as a design element. Wood is a biological building product, and individual components in a building will vary in appearance, properties and performance. Life expectancy of wood and wood-based products is related to a number of factors. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood material, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within a small limited area. The overall objective of this thesis was to gain in-depth knowledge about which factors influence surface mould growth on coated and uncoated wooden cladding in an outdoor environment, with a special attention to modified wood substrates. The work included identification of fungal species on the surface of coated substrates, studies of modified wood substrates\" susceptibility to mould growth, investigation of paints with different physical surface structures and their influence on surface mould growth, identification and quantification of factors that contribute to variation in surface mould growth and prediction of future performance of combinations of wood substrates and coating systems.....
Authors
Adam ParuchAbstract
No abstract has been registered
Abstract
The most important and widespread disease on golf courses is Microdochium nivale. It is a psycrotrophic fungal plant pathogen that is the main cause of biotic winter injury in grasses in the temperate and sub-arctic climates, both with and without snow cover. It is an opportunistic pathogen, with the ability to attack plants under a wide range of environmental conditions. A large variation in both host preference and aggressiveness among isolates has been documented. It is speculated that these traits as well as competition between isolates may be dependent on temperature. The fungus is spread by infected seeds and from infected plants or debris. Besides seed transmitted inoculum, it is not clear whether the primary inoculum source is wind dispersed ascospores or soilborne/plant debris borne inoculum. Wind borne ascospores has been claimed to be the main inoculum source, but perithecia are hardly observed on grasses on Norway. The aim of the present project was obtain better understanding of what is the source of primary inoculum for snow mould caused by M. nivale; to understand how inoculum of M. nivale survives from spring to fall, and from year to year, to understand how climatic conditions affects the potential inoculum by monitoring symptoms on plants, occurrence of the fungus and growth characteristics in vitro of strains sampled from snow melt and through summer and autumn. To obtain such knowledge, surveys and sampling on selected golf courses was conducted. Snow mould symptoms and the occurrence of M. nivale in leaves and stems of grasses sampled from golf greens and foregreens was reduced during the growth season. We also found that M. nivale could be isolated from locations without visible symptoms. Despite a lower isolation rate in autumn, M. nivale was again isolated in some of the originally locations, the following spring. The M. nivale isolation rate was similar from sites located on greens compared to foregreens, and from greens located at more sunny sites compared to more shadowy located greens. We conclude that this fungus seem to survive from year to year within the same locations on greens and foregreens.
Authors
Fushi Wen Ho Hyung Woo Elizabeth A. Pierson Toril Eldhuset Carl Gunnar Fossdal Nina Elisabeth Nagy Martha C. HawesAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Kristine Marie Olsen Rune Slimestad Unni Synnøve Lea Cato Brede Trond Karsten Løvdal Peter Ruoff Michel Verheul Cathrine LilloAbstract
The flavonoid pathway is known to be up-regulated by different environmental stress factors. Down-regulation of the pathway is much less studied and is emphasized in the present work. Flavonoid accumulation was induced by exposing plants for 1 week to nitrogen depletion at 10 degrees C, giving high levels of anthocyanins and 3-glucoside-7-rhamnosides, 3,7-di-rhamnosides and 3-rutinoside-7-rhamnosides of kaempferol and quercetin. Flavonol accumulation as influenced by temperatures and nitrogen supply was not related to the glycosylation patterns but to the classification as quercetin and kaempferol. When nitrogen was re-supplied, transcripts for main regulators of the pathway, PAP1/GL3 and PAP2/MYB12, fell to less than 1 and 0.1% of initial values, respectively, during 24 h in the 15-30 degrees C temperature range. Anthocyanins showed a half-life of approximately 1 d, while the degradation of flavonols was much slower. Interestingly, the initial fluxes of anthocyanin and flavonol degradations were found to be temperature-independent. A kinetic model for the flavonoid pathway was constructed. In order to get the observed concentration-temperature profiles as well as the temperature compensation in the flavonoid degradation flux, the model predicts that the flavonoid pathway shows an increased temperature sensitivity at the end of the pathway, where the up-regulation by PAP/GL3 has been found to be largest.
Authors
Anita Sønsteby Ola M. HeideAbstract
The effect of night temperature on short day (SD) floral induction in three June-bearing strawberry cultivars of different geographic origin was studied and compared with yield performance in the cool Nordic environment. At the optimum day temperature of 18°C, the SD flowering response of the cultivars ?Florence? and ?Korona? increased significantly with increasing night temperature from 9 to 18°C, while an optimum was reached at 15°C in ?Frida?, a cultivar selected under coolenvironment conditions in Norway. Also, while saturated flowering response was obtained with three weeks of SD treatment at all temperatures in ?Frida?, several plants of ?Florence? and ?Korona? failed to initiate flowers at 9°C night temperature even with five weeks of SD. The effect of extended SD period was particularly pronounced in ?Florence?. The slow SD floral induction response of ?Florence? was associated with a two-week delay of anthesis in subsequent long day (LD) conditions at 21°C. Performance studies of the same cultivars during two years under field conditions also demonstrated that the yield potential of ?Florence? was not realized under the climatic conditions prevailing at these locations. The yields varied significantly among the cultivars, ?Frida? having the highest yields, followed by ?Korona? and ?Florence? far below. It is concluded that, in the Nordic environment, autumn (September) night temperatures are obviously sub-optimal for yield performance of some June-bearing strawberry cultivars, and that this effect is mediated by autumn temperature effects on flower initiation responses. In the biennial-fruiting raspberry cultivar ?Glen Ample?, flowering and dormancy induction are controlled by the interaction of low temperature and short photoperiods. As neither process takes place at temperatures above 15°C regardless of the photoperiodic conditions, low temperature is of crucial regulatory importance. Environmental control of annual-fruiting cultivars is also briefly discussed.
Authors
Daniel P. Rasse Karin Knoth de Zarruk Line Tau StrandAbstract
No abstract has been registered