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
Hege Nordheim-Viken Harald VoldenAbstract
It is concluded that the ruminal aNDF degradation characteristics are affected by maturity Stage, and interactions with climatic factors such as temperature and water availability probably interact with maturity stage. Precautions should he made when prediction feed degradation characteristics from multiple regression analyses. (C) 2008 Published by Elsevier B.V.
Authors
Geir Mathiesen Anita Sveen May Bente Brurberg Lasse Fredriksen Lars Axelsson Vincent EijsinkAbstract
Conclusion: This is the first comprehensive experimental study showing that predicted SPs in the L. plantarum genome actually are capable of driving protein secretion. The results reveal considerable variation between the SPs that is at least in part dependent on the protein that is secreted. Several SPs stand out as promising candidates for efficient secretion of heterologous proteins in L. plantarum. The results for NucA provide some hints as to the sequence-based prediction of SP functionality, but the general conclusion is that such prediction is difficult. The vector library generated in this study is based on exchangeable cassettes and provides a powerful tool for rapid experimental screening of SPs.
Abstract
Published data of pH and conductivity in some acid humic waters have shown erroneous corresponding values. This means that the values were not consistent with each other according to well-recognized hydrochemistry. A main questions was arised in this connection. Were the measurements correct and if not which of them were wrong, pH, conductivity or both ? Assessment on basis of calculated and measured conductivity values, by using published data and own measurements, indicate primarily erroneous pH measurements. This makes the scientific papers which are based on these remarkable results partly of questionable value. Conductivity should generally act as a controlling parameter even if the latter also could have some uncertainties.
Abstract
Organochlorine pollutants in the major fish species (pike Esox lucius, perch Perca fluviatilis, and roach Rutilus rutilus) of Lake Arungen, Norway, were investigated after an extensive removal of large pike in 2004. The organochlorine pollutants detected in fish liver samples in 2005 were dichlorodiphenyltrichloroethane (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and heptachlor epoxide (HCE). DDTs were the dominant among all analyzed OCs. Sigma PCB and HCB, detected in fish from two clearly distinct trophic levels (prey and predators), give an indication of biontagnification. All OC concentrations in female pike were significantly lower compared to males, which might be due to the removal of high concentrations of pollutants in roe during spawning. (c) 2009 Elsevier Ltd. All rights reserved.
Abstract
No abstract has been registered
Abstract
In the Nordic strawberry industry only single-cropping cultivars are used. Several everbearing cultivars have been tried, but neither yield nor quality has been satisfactory. In 2005, new everbearing cultivars were collected and an experiment was established in a polyethylene tunnel. Yield and runnering capacity were recorded in two seasons. The cultivars were the English 'Flamenco' and 'Everest', the Dutch 'Elan' and the Norwegian 'Rita', 'Rondo', 'Ridder' and 'Rosa'. Plug plants were planted in double rows on low ridges mulched with plastic at a plant density equivalent to 50,000 plants per ha. A block design with 20 plants per plot and four replicates was used. The field was harvested two to three times a week during the whole season from June until the beginning of October in both years. Berry size was recorded at all harvests while taste and general performance were evaluated using a scale 1-9. In the first year, the everbearing cultivars had significantly higher yield than the single-cropping cultivars due to more inflorescences, but this was levelled out the second year. While the cropping season of the single-cropping cultivars is only about four weeks, the everbearing cultivars were picked from late June until beginning of October, in both years. The highest yields were obtained by 'Everest' (729 and 844 g) followed by 'Rita' and 'Ridder'. The cultivars 'Elan' and 'Rondo' scored highest both in taste and general performance. 'Everest' also performed well, but flavour was not acceptable.
Authors
Anita Sønsteby Ola M. HeideAbstract
Octoploid strawberry (Fragaria × ananassa Duch.) cultivars can be classified into mono-flowering (single-cropping or June-bearing) and perpetual-flowering (everbearing) types according to their horticultural performance. Whereas floral induction in mono-flowering cultivars is well-documented, the literature on the control of flowering of perpetual-flowering cultivars is rather inconsistent. Photoperiod and temperature control of flowering in several perpetual-flowering strawberry cultivars of widely varying pedigree were therefore studied in controlled environments. Flower bud initiation in all cultivars was significantly advanced by long day (LD) conditions at temperatures of 15°C and 21°C; while, at 27°C, flowering took place under LD conditions only. When vegetative plants growing in short day (SD) at 27°C were transferred to LD conditions at the same temperature, they consistently initiated flower buds and started flowering after about 4 weeks. At such a high temperature, flowering could thus be turned on and off by switching between SD and LD conditions. At 9°C, flowering was substantially delayed, and, at this temperature, flowering was unaffected by photoperiod. Runner formation was generally promoted by high temperature and SD conditions, but the photoperiodic effect varied between experiments. We conclude that everbearing strawberry cultivars, in general, whether of the older European type or the modern Californian type, are qualitative (obligatory) LD plants at high temperature (27°C), and quantitative LD plants at intermediate temperatures. Only at temperatures below 10°C these cultivars are day-neutral.
Abstract
The effects of timing of nitrogen (N) fertilization relative to the beginning of a 4-week floral-inducing short-clay (SD) period have been studied in 'Korona' strawberry plants under controlled environment conditions. Groups Of low fertility plants were fertilized with 100 ml of calcium nitrate solution for 3 days a week for a period of 3 weeks starting at various times before and at the beginning of the SD period, as well as at different times during the SD period. All plants, including SD and long day (LD) control plants, received a weekly fertilization with a low concentration complete fertilizer Solution throughout the experiment. Leaf at-ea. fresh and dry matter increments of leaves, crowns and roots, as well as leaf chlorophyll concentration (SPAD Values) were monitored during the experimental period. A general enhancement of growth took place at all times of N fertilization. This was paralleled by an increase in leaf chlorophyll concentration, indicating that the control plants were in a mild state of N deficiency. When N fertilization was started 2 weeks before beginning of the SD period, flowering was delayed by 7 days, and this was gradually changed to an advancement of 8 days when the same treatment was started 3 weeks after the first SD. The amount of flowering was generally increased by N fertilization although the effect varied greatly with the time of N application. The greatest flowering enhancement Occurred when N fertilization started I week after the first SD when the number of flowering crowns and the number of inflorescences per plant were more than doubled compared with the SD control, while fertilization 2 weeks before SD had no significant effect on these parameters. Importantly, the total number of crowns per plant was not affected by N fertilization at any time, indicating that enhancement of flowering was not due to an increase in potential inflorescence sites. No flowering took place in the control plants in LD. Possible physiological mechanisms involved and practical applications of the findings are discussed. (C) 2009 Elsevier B.V. All rights reserved.
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
Vibeke Lind Jan Berg Lars Olav Eik Jørgen A.B. Mølmann Espen Haugland Marit Jørgensen Margrethe HerslethAbstract
Many consumers perceive lamb meat from mountain pastures to be of superior quality, a quality that may be altered if lambs are kept for a longer period on cultivated pastures before slaughtering. The objective of this experiment was to compare sensory profile and fatty acid composition in meat from lambs slaughtered directly from unimproved mountain pastures with meat from lambs raised on unimproved mountain pastures and fattened on biodiverse cultivated pastures for 26, 39 and 42 days before slaughtering. The experiment was conducted at two different locations in Norway in 2006 and 2007, with a total of 124 Norwegian Crossbred Sheep lambs. Loin samples of M. Longissimus dorsi from lambs above a body weight of 40 kg were selected and analysed for sensory attributes. Fatty acid composition was determined in the subcutaneous fat over the Longissimus dorsi. Small but significant differences were found in hardness, tenderness, fattiness, metallic and rancid flavour, and in polyunsaturated fatty acids. This indicates that to a small extent pre-slaughter fattening on cultivated pastures alters meat characteristics. (C) 2009 Elsevier Ltd. All rights reserved.