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.
2023
Authors
J. O’Malley J.A. Finn C.S. Malisch P.R. Adler M. Bezemer A. Black Åshild Gunilla Ergon J. Eriksen S. Filley A. Fiorini P. Golinski G. Grange J. Hakl Y. He N. Hoekstra P. Högy O. Huguenin-Elie M. Ibanez R. Jiaxin J. Jing J. Jungers Z. Kadžiulienė D. Krol J Lajeunesse G. Louarn S. Meyer T. Moloney G. Peratoner C. Porqueddu C. Reynolds Ievina Sturite M.N. Thivierge F. Zhu C. BrophyAbstract
LegacyNet is a voluntary network of 32 international sites, established to investigate the yield benefits of multispecies grassland leys and their legacy effects on a follow-on crop. Relatively few experiments have investigated the impact of manipulating species diversity in grassland leys within crop rotations, and fewer still have accounted for variability across environments and soil types. A common experiment is being conducted at all 32 LegacyNet sites, with 52 grassland plots of systematically varied combinations of six forage species from three functional groups (two grasses, two legumes and two herbs) being sown at each site. The plots are measured and harvested for a period of at least 18 months. After this time, grassland plots are terminated, and a follow-on crop established on each plot (retaining the same plot structure). Measurements taken during the grassland and follow-on crop stages include dry matter yield, forage quality, botanical composition, and legacy effects. In this paper, we introduce the LegacyNet international experiment, its design, and overall aims and objectives.
Abstract
Despite newly approved lucerne cultivars, this has not led to increased use of this legume in high-latitude agriculture. Challenges with inoculation by Rhizobium meliloti have been identified as a bottleneck to adaptation. Here we tested inoculation sources (ISs) with soil types and cultivars in pot and field experiments. During a one-year outdoor pot experiment, we tested the impact of IS (wet peat slurry and Nitragin Gold dry inoculation) and three soil types (sand, sandy silt and /peat soil) on nodule development, shoot and root growth and winter survival of one hybrid lucerne cultivar (‘Ludvig’). The pot experiment revealed that dry inoculation led to significant better plant growth, flower and nodule development as well as plant regrowth after winter survival. Peat soil appeared as the best growth medium and silty soil limited inoculation efficiencies. In field trials at two locations differing in soil characteristics using similar ISs, and three hybrid lucerne cultivars (‘Lavo’, ‘Live’ and ‘Lotte’) biomass yield during two ley years showed site as well as cultivar differences. Such environmental interactions in the field trials justify the use of adapted cultivars, and dry inoculation should be recommended for practical use replacing peat slurry inoculation.
Abstract
The use of cover crops in cereal production as a climate smart agricultural practice is generally used to increase carbon sequestration in soils. However, increased plant biomass in wintertime can trigger N2O emissions due to decay during freeze-thaw cycles. So far little is known about N2O winter emissions from cover crops which, in the worst case, could cancel out the carbon gain by cover crops. Here we report N2O emissions from a two-year field experiment in SE Norway with barley and various cover crops (perennial and Italian ryegrass, oilseed radish, summer and winter vetch, phacelia and a mixture of different herbs) measured against controls without cover crops. A field robot was used for measuring N2O emissions at high temporal resolution during off-season, i.e., the period from cereal crop harvest to cereal crop sowing. During the first winter, the snow cover was poor and the significantly higher N2O emissions were measured from oilseed radish during spring thaw whereas perennial ryegrass reduced emissions. A second winter is measured and N2O emissions from both years will be presented. In addition, continuous measurements are needed to assess the effect of diurnal freeze-thaw cycles on N2O emissions before scaling up to annual N2O emission fluxes and comparing with C sequestration.
Abstract
Cover crops are used to increase carbon sequestration in soils. However, an increase of organic matter in soils not only increases carbon stocks but also affects nitrogen availability. This can trigger N2O emissions, particularly during wintertime, when standing plant biomass from cover crops decays. N2O emissions associated with cover crops could potentially cancel out the carbon gain. In this study, N2O emissions were measured over two years in a field experiment in SE Norway with barley and various cover crops (perennial and Italian ryegrass, oilseed radish, summer and winter vetch, phacelia and a mixture of different herbs) and compared with controls without cover crops. Manual chambers were used in summer during the growth of the main crop, while winter emissions were measured more frequently by a field robot to capture freeze-thaw induced emission peaks. Both winters had poor snow cover and the highest N2O emissions were measured during freeze-thaw cycles in early spring. Nitrogen-rich cover crops with poor overwintering (oilseed radish) increased wintertime emissions, whereas perennial cover crops with good overwintering (perennial ryegrass and herb mixture) tended to reduce N2O emissions compared to controls. This suggests that the overall climate effect of cover crops in hemiboreal cereal production depends on cover crop species and winter conditions.
Abstract
Vaccinium berries include several economically important cultivated and wild species such as blueberries, cranberries, bilberries and lingonberries. These species are recognized for the various health beneficial properties, which are generally linked to the high yields and the complex profile of flavonoids in the berries, including anthocyanin, proanthocyanidin, and flavonol classes of flavonoids. Anthocyanins are one of the main pigments in plants contributing to the characteristic reddish to bluish colours in flowers and fruits. Most important anthocyanins are glucosides of six common aglycons: cyanidins, delphinidins, pelargonidins, petunidins, peonidins and malvidins. Of these, delphinidin branch anthocyanins, namely delphinidins, petunidins, and malvidins are responsible of bluish colours in blue Vaccinium berries. The biosynthesis of anthocyanins has been intensively studied, and the structural enzyme genes responsible of the specific steps of the pathway have been characterised also in diverse Vaccinium species. For the delphinidin branch, flavanone 3’5’ hydroxylase (F3’5’H) is the key enzyme for the branching point towards bluish anthocyanins. Our recent results both from controlled and field experiments have revealed new information on the key regulators controlling the different branches of the anthocyanin biosynthesis in blue-coloured berries. Transcriptome analyses combined with metabolite results have identified signaling routes leading to increase in delphinidin branch anthocyanins. Our results show that the anthocyanin composition in blue Vaccinium berries could be modified by specific environmental factors.
Authors
Amos Samkumar Rajan Premkumar Katja Hannele Karppinen Inger Martinussen Richard V. Espley Laura Elina JaakolaAbstract
Wild berries are abundant in health-beneficial bioactive compounds, such as flavonoids, carotenoids, vitamins, and polyphenolic compounds, which accumulate during the fruit ripening process. Interestingly, wild Vaccinium berries from northern latitudes are found to contain more bioactive compounds compared to southern clones. The genetic adaptation is most likely favoured by environmental conditions, such as extended day length, cool temperatures and light spectral qualities. The molecular mechanisms underlying the regulation of secondary metabolite biosynthesis in response to light quality have been scarcely explored in Vaccinium berries. The present study is focused on gaining knowledge on the regulatory process under supplemental red and blue light in non-climacteric wild bilberry (Vaccinium myrtillus L.). Controlled experiments were carried out in phytotrons with local Norwegian ecotypes of bilberry, which were subjected from early to late ripening stages to continuous exposure to specific red and blue wavelengths provided by light-emitting diodes (LEDs). Berry samples from mid-ripening stage were utilized for the gene expression analysis based on RNA-seq transcriptome profiling. Our recent analyses from the transcriptome data set have shown that light wavelengths induce the anthocyanin biosynthetic genes, resulting in higher delphinidin accumulation in ripe bilberries. The enhanced secondary metabolic pathways influenced by such light qualities and the differential expression patterns in light-reaction centers as observed in various subunit complexes of photosystem I and II in the photosynthetic apparatus are briefly discussed in this study. This is crucial in order to study how plants acclimatize to modified light environment in terms of photosynthesis. The differences in expression of hormone signal transduction pathway genes were also discussed. The results will contribute to a better understanding of the light-mediated biosynthesis of phytochemicals in Vaccinium berries.
Authors
Pia Heltoft ThomsenAbstract
No abstract has been registered
Authors
Pia Heltoft ThomsenAbstract
No abstract has been registered
Authors
Pia Heltoft ThomsenAbstract
No abstract has been registered
Authors
Vibeke LindAbstract
No abstract has been registered