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.
2010
Authors
Arild Andersen Trond Hofsvang May Bente Brurberg Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn Økland Leif SundheimAbstract
No abstract has been registered
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No abstract has been registered
Abstract
Roseroot, Rhodiola rosea, is a perennial herbaceous plant of the family Crassulaceae. The rhizomes of 95 roseroot clones in the Norwegian germplasm collection were analysed and quantified for their content of the bioactive compounds rosavin, salidroside, rosin, cinnamyl alcohol and tyrosol using HPLC analysis. All five bioactive compounds were detected in all 95 roseroot clones but in highly variable quantities. The ranges observed for the different compounds were for rosavin 2.90-85.95mgg-1, salidroside 0.03-12.85mgg-1, rosin 0.08-4.75mgg-1, tyrosol 0.04-2.15mgg-1 and cinnamyl alcohol 0.02-1.18mgg-1. The frequency distribution of the chemical content of each clone did not reflect a certain geographic region of origin or the gender of the plant. Significant correlations were found for the contents of several of these bioactive compounds in individual roseroot clones. A low, but not significant correlation was found between AFLP markers previously used to study the genetic diversity of the roseroot clones and their production of the chemical compounds. The maximum level of rosavin, rosin and salidroside observed were higher than for any roseroot plant previously reported in literature, and the roseroot clones characterized in this study might therefore prove to be of high pharmacological value.
Abstract
No abstract has been registered
Authors
Karl ThunesAbstract
No abstract has been registered
Abstract
In 1955 the potato cyst nematode (PCN) was recorded for the first time in Norway. This detection resulted in extensive surveys and measures were implemented based on the statutory regulation of 1916. The first statutory regulation for PCN was put in power in 1956, and later amended in several occasions. These regulations prohibit the introduction and spread of PCN with soil and plant materials. Early control strategies included the use of chemical fumigants and resistant potato cultivars in infested fields, and surveys detected new infestations which were placed under quarantine regulations. The recognition of G. rostochiensis and G. pallida, their pathotypes enabled a more precise use of resistant cultivars. Commercial chemical fumigants, organophosphates or carbamate nematicides have not been used in Norway since the early 1970s. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in at least 40-years ban for growing potato. Most Norwegian potato cultivars have the resistance genes, Gro-1 (H1) from Solanum tuberosum ssp. andigena. During the preceding decades great emphasis has been placed on documenting freedom from PCN in the production of certified seed potatoes, certified seed potato are used in combination with crop rotations using non-host crops, alternating susceptible and resistant cultivars. These are important control measures, but not easy to implement in Norway due to restricted acreage suitable for long rotations. The safe use of resistant potato cultivars requires a better knowledge on the presence of species and pathotypes in potato fields. In order to improve our information of the occurrence of PCN a new national survey program for the principal potato districts has started. These surveys will complemented by information generated from a new research project dealing with: studies of the virulence of selected PCN populations, decline rates of nematode field population densities and infection potential over time of populations from fields placed under quarantine regulations. studies on the occurrence and pathogenicity of microbial antagonistic parasitic on PCN, and their potential of future management of PCN, the safe use of early potato cultivars as a practical control method, and the potential for using Solanum sisymbriifolium as a trap crop, distinguish the degree of resistance of selected potato varieties available on the Norwegian market, and initial studies of the PCN-Potato-Pathosystem. These expected results of this project possibly will improve the management of PCN, and may alleviate present regulatory restrictions.
Abstract
In Nordic countries organic farming started as bio-dynamic farms in the 1930s, and still in the 1970s only a small number of farms were organic. Since then the acreage of organic farming has increased and in 2007 Sweden had 222 268 ha (7.9%), Finland 147 557 ha (6.4 %), Denmark 147 482 ha (5.4%), Norway 43 033 ha (4.7%) and Iceland 4 684 ha (0.27%). In northern areas the short vegetation period combined with low temperatures reducing mineralisation causing nutritional deficit may restrict yields. As mineral fertilizers are prohibited in organic farming, plant nutrition and yield depend on proper microbial activity for nutrient cycling. Plant parasitic nematodes (PPN) reduce plant growth, while microbivorous nematodes (MBN) increase nutrient accessibility. Nitrogen fixating legumes, used to improve soil nitrogen levels, may increase densities of PPN to levels causing crop damage. Management of PPN in organic farming relies on knowledge of population dynamics, damaging thresholds and cultural methods like weed control, sanitation, mulching, crop rotation and resistant cultivars. Keeping PPN below damaging levels and supporting beneficial MBN to improve mineralisation would increase yields and improve quality of organics crops in northern areas. Management of MBN is less well understood, but may be of crucial importance for organic farming in northern areas.
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Arild Sletten Birger Solberg Halvor Solheim Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Leif Sundheim Trond Hofsvang Christer Magnusson Trond Rafoss Arild Sletten Halvor Solheim Arne Stensvand Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
No abstract has been registered