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
Lukas Gudmundsson Holger Lange Lena M. Tallaksen Kerstin StahlAbstract
No abstract has been registered
Abstract
The estrogenic mycotoxin zearalenone (ZON) produced by some Fusarium spp. causes reproductive problems and hyperestrogenic syndromes in mammals. In an effort to elucidate the molecular pathways of ZON production, we present a comparative real-time quantitative polymerase chain reaction expression study of seven contiguous genes in the ZON biosynthetic cluster on sterile rice and during wheat and oat infection. Under ZON production on rice, the polyketide synthase (PKS) genes PKS4 and PKS13, alcohol oxidase FG12056 gene, and transcriptional regulator FG02398 gene showed similarly upregulated patterns, whereas the nonribosomal peptide synthetase (NPS) FG02394, the K+ channel beta subunit FG12015, and the protein kinase FG02399 displayed a variant pattern. During the same time period under wheat infection when no ZON was produced, the PKS genes and the NPS were downregulated relative to rice whereas the K+ channel beta subunit gene FG12015 was markedly upregulated, suggesting that it may play a role in the infection process. This is the first expression study of ZON biosynthetic genes in planta. The results give insight into the regulation and activities of the ZON gene cluster under different experimental systems and suggest a connection between ZON and a K+ channel that could reveal a novel function for ZON in Fusarium spp.
Abstract
Yields are reported from four long-term (16 30 years) tillage trials, comparing results since 1998, under relatively wet conditions, with earlier experience. In trial 1, on clay loam, mean grain yield with spring harrowing only, has since 1998 been 87% of that obtained with autumn ploughing, whereas it was 94% for the whole period since 1991. The inclusion of autumn harrowing increased these figures to 94 and 98%, respectively. Over the last six years, spring ploughing gave 5% lower yield than did autumn ploughing. Relative yields of unploughed versus ploughed treatments were negatively correlated with summer rainfall. Grain protein was lowest with spring harrowing only. In trial 2, on clay loam, direct drilling has since 1998, as in previous years, given around 10% lower yield than has autumn ploughing. Autumn harrowing gave 4% lower yield in winter wheat and 6% higher yield in spring oats than did autumn ploughing, whilst yields of spring turnip rape were not significantly affected by tillage. In trial 3, also on clay loam, six alternative straw treatments were compared under four unploughed tillage regimes. Relative to straw removal, retaining large residue amounts depressed yields hardly at all with autumn and spring harrowing, but by 7% with spring harrowing only and by 13% with direct drilling. Overall, direct drilling gave 18% lower yields in this trial than did autumn and spring harrowing, whilst the yield reduction with spring harrowing only was 7%. In trial 4, on silt loam, both spring harrowing only and direct drilling have since 1998 given 6% lower yield than has autumn ploughing, whereas autumn and spring harrowing has given 6% higher yield. Under drier conditions during 1991 1997, autumn ploughing gave up to 11% lower yield than did unploughed treatments. Straw retention was beneficial in the absence of ploughing during that period, but has had little effect in more recent years.
Abstract
General questions that arise while investigating hydrological extremes are whether these have distinct spatial and temporal variations and how these variations are linked to mean flow conditions. We analyze a large set of European stream flow series. Based on daily observations we derive annual series of stream flow deciles ranging from the minimum to the maximum, resulting in a set of eleven series for each station representing the year to year variability of the flow regimes....
Authors
Lukas Gudmundsson Lena M. Tallaksen Kerstin Stahl Holger LangeAbstract
No abstract has been registered
Authors
Reidun Pommeresche Anne-Kristin LøesAbstract
This paper presents Norwegian studies of earthworms (density, biomass, burrows density, species, juvenile to adult ratios) in arable soil in Norway conducted during the last 20 years. The effects of crop rotations, fertilization, soil tillage and compaction on earthworms are presented, based on various field experiments. Geophagous (soil eating) species such as Aporrectodea caliginosa and A. rosea dominate the earthworm fauna in Norwegian arable soil. Lumbricus terrestris is also present; in our studies even frequently found in an all-arable crop rotation with annual ploughing. In southern Norway, L. rubellus, and A. longa are commonly found. Earthworm density, recorded in autumn varied between 30 and 350 individuals m-2 in different studies, with the lowest values found in conventional all arable farming systems. One year of ley in the crop rotation increased earthworm burrow density, earthworm density and biomass. Even short-term leys for green manure had a positive effect, likely due to high clover content. Application of animal manure increased earthworm density and biomass. Because geophagous species prefer the upper soil layer, shallow ploughing (15 cm depth) was expected to be detrimental. However, the earthworm density and biomass was not lower with shallow as compared to deep ploughing (25 cm depth). With earthworm densities such as those found in farming systems with ley and animal manure, an estimated amount of 221 tonne of topsoil per hectare passes through the earthworm digestion system within one year. Field-collected geophagous earthworm casts had considerably higher concentrations of plant nutrients than bulk soil (28% higher concentration of Tot-N, 36-53% for PAL, 40%-59% for KAL). Earthworm casts are significant natural sources of plant nutrients, also in soils with high dominance of geophagous earthworm species.
Abstract
No abstract has been registered
Authors
Bruce Talbot Pierre AckermanAbstract
No abstract has been registered
Authors
Mensur Vegara Thor S. Larsen Hans Magnus Gjøen Anders Kiessling Roger K. Abrahamsen Ole Hofstad Lars Helge Frivold Bal Ram Singh Gunnar Klemetsdal Geir-Harald Strand Dag Ragnar Blystad Åsmund AsdalAbstract
The main objectives under this programme were: - To improve organising, content and quality of academic education and research in agriculture, veterinary medicine and forestry to meet with needs for qualified people in ongoing rebuilding after wars and to reach the general European level and standards. - Create functional and sustainable networks of regional institutions and professionals to support each other and cooperate for optimal use of limited available resources in the SEE region in a difficult rebuilding situation. The main activities were: - Research and development projects in the areas of animal sciences, crop and fodder production and use of GIS-methods in forestry and agriculture. - Support to development of staff and institutions in form of study stays, study material, covering of costs for laboratory analysis etc. related to M.Sc. and Ph.D. thesis work, guest lecturing and some equipment. - Support to reorientation of academic education in agriculture, forestry and veterinary medicine. - Support to regional networks, professional meetings, further development and use of the Programme web site and web-based teaching. The most important strategy in this Programme was to facilitate for institutional cooperation and network building between partners in the SEE area. Therefore a broad approach was chosen with a large number of partners (16) from all actual geographical areas in SEE - West Balkan - (Albania, Bosnia & Herzegovina, Croatia, Kosovo, Macedonia and Serbia & Montenegro) and representing most of the different ethnical groups in the region. The main intensions under the new programme is to improve the organisation, content and quality of academic education, research and support services in the faculties of agriculture, veterinary medicine and forestry in order to meet national needs in the ongoing reconstruction after the regional wars. Programme activities include activities that: ? Support and strengthen selected institutions in SEE/WB towards obtaining European professional levels and standards. ? Promote networking and scientific cooperation between the SEE/WB institutions. ? Promote networking and scientific cooperation between institutions in SEE/WB and in Norway.
Authors
Galina Koptsik Toril Drabløs Eldhuset Sergey Koptsik Dan AamlidAbstract
No abstract has been registered