Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2012
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Marit Jørgensen Rebekka M L Helgesen Margrete Eknæs Jørgen A.B. Mølmann Håvard SteinshamnSammendrag
Det er ikke registrert sammendrag
Forfattere
Marit Jørgensen Rebekka M.L. Helgesen Margrete Eknæs Jørgen A.B. Mølmann Håvard SteinshamnSammendrag
Norwegian goat milk production is based on summer grazing on diverse forest or alpine rangeland, and the quality of these pastures is important for milk quantity and quality. We used n-alkanes and long chained alcohols found in plant wax as markers to estimate diet composition in goats grazing on a heterogeneous rangeland during two periods in summer; early (beginning of July) and late (end of August). The goats were fitted with GPS collars that recorded their position. Preliminary results show a diverse diet, where ferns, sedges, blueberry (Vaccinium myrtillis) and birch were preferred in early summer. In late summer the diet was particularly diverse, coinciding with a general decline in plant quality.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Jens Rohloff Eivind Uleberg Laura Jaakola Kajetan Trost Olavi Junttila Hely Häggman Inger MartinussenSammendrag
Individual bilberry plants from two Northern and two Southern clones were studied for climatic effects on production and quality in a controlled phytotrone experiment at 12 °C and 18 °C in a 2-year trial. At each temperature the following light conditions were tested: 1) 12 h natural light (short day); 2) 24 h natural light (long day) and 3) 24 h natural light (long day) plus red light. In order to ensure sufficient and comparable fruit set between treatments, flower pollination was executed outdoors. Berry yield, quality parameters such as total anthocyanins, total phenols and antioxidant capacity, and chemical composition (GC/MS-based metabolite profiling) were recorded in both years, while HPLC-based anthocyanin analysis was only carried out in the second year. All analyzed compounds showed significant year-to-year variation with the exception of antioxidant activity. The experiment was conducted under natural light conditions, and therefore light intensity and quality varied between the two growing seasons. The first experimental year there was no difference in yield between temperatures, however, the second experimental year the berry yield was significantly higher at 18 °C. Temperature treatments led to faster berry ripening in the Northern than in the Southern clones at 12 °C. Metabolite profiling also revealed higher levels of flavanols, hydroxycinnamic acids, quinic acid and carbohydrates at 12 °C. Clonal effects showed that the content of all anthocyanin derivatives, as well as levels of antioxidants, total phenolics, malic acid and sucrose were highest in the Northern clones, while Southern clones had higher levels of hydroxycinamic acids, epicatechin, quinic acid and myo-inositol. Northern clones were also more responsive to additional red light with highest levels of anthocyanins under long-day treatment.
Forfattere
Muath Alsheikh-Yousef Gage Koehler Robert Wilson Jens Rohloff Anita Sønsteby Jahn Davik Stephen K, RandallSammendrag
A crucial consideration for strawberry producers in Norway and other northern countries is winter freezing damage. A long-term goal of the Norwegian strawberry breeding is to increase winter hardiness and to improve fruit quality. Due to the complexity involved in regulating and enhancing freezing tolerance, the progress in the improvement of cultivars using traditional screening methods have had limited success. Thus, the development of molecular markers for freezing hardiness would facilitate the selection work for this trait. In this effort, we have developed and adopted state-of-art molecular tools to investigate cold response in strawberry plants during the acclimation phase resulting in the identification of a large number of genes, proteins, and distinct metabolites that correspond to cold/freezing tolerance in strawberry. To identify proteins responsible for freezing tolerance in strawberry we have examined alterations in protein levels in strawberry varieties that differ in cold tolerance using either 2-DE gel analysis followed by LC-MS/MS analysis or a shotgun MS/MS approach. Proteomic analysis suggested 30 potential biomarkers that showed significant changes in the cultivated strawberry in response to cold. In addition, GC-MS-based metabolite profiling revealed the up-regulation of carbohydrates, polyols, amino acids, TCA intermediates, and other distinct secondary metabolites after cold treatment. Transcriptional analysis of the cold acclimated samples also confirmed the regulation upon cold-treatment with varietal differences in strawberry. Moreover, several F2-populations from the model F. vesca parents diverging in cold tolerance have been developed in order to facilitate mapping of QTLs by performing GBS analyses. The knowledge attained from these endeavors is expected to expedite breeding of strawberries to achieve freezing tolerant lines and provide an integrative understanding of the molecular pathways that underlie this characteristic. * Rohloff et al. (2012) Metabolite profiling reveals novel multi-level cold responses in the model Fragaria vesca. Phytochemistry 79:99-109. * Koehler et al. (2012) Proteomic study of low temperature responses in strawberry cultivars (Fragaria x ananassa) that differ in cold tolerance. Plant Physiology 159:1787–1805 * Davik et al., (2012) Low temperature tolerance in diploid strawberry species (Fragaria ssp.) and its correlation to alcohol dehydrogenase levels, dehydrin levels, and central metabolism constituents. Planta (in press; DOI: 10.1007/s00425-012-1771-2).
Forfattere
Per Jarle MøllerhagenSammendrag
Det er ikke registrert sammendrag
Forfattere
Inger MartinussenSammendrag
Det er ikke registrert sammendrag
Forfattere
Margarita Novoa-Garrido Celine Rebours Ingunn Øvsthus Marte Meland Christian Guido Bruckner Pierrick Stevant Christian Uhlig Åsbjørn KarlsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Gage Koehler Jens Rohloff Robert Wilson Per Winge Anita Sønsteby Muath Alsheikh Stephen K, RandallSammendrag
There is limited research about variations between cultivars for freezing tolerance in fruit crops and indeed much less is known about the distinctive in ground structure of the crown that herbaceous perennials depend on for regeneration in spring. Because strawberry is a representative species for the Rosaceae crops knowledge gained is expected to be transferrable to benefit improvement of many of these related crops. To gain insight into the molecular basis that may contribute to overwintering hardiness, a comparative proteomic analysis was carried out for four Fragaria x ananassa (octoploid strawberry) cultivars that differ in freezing tolerance. Protein expression was investigated in the overwintering relevant crown structure of strawberry from plants exposed to 0, 2, and 42 day cold treatments and were examined by two-dimensional gel electrophoresis (2D). Some proteins, such as molecular chaperones, antioxidants / detoxifying enzymes, metabolic enzymes, and pathogenesis related proteins were revealed to be at significantly higher levels before cold exposure in the most freezing tolerant cultivars, (‘Jonsok’ and ‘Senga Sengana’) compared to the least tolerant cultivars (‘Frida’ and ‘Elsanta’). Freezing tolerance was evaluated for the cultivars before and after cold exposure, with findings that support that the most freezing tolerant cultivars are poised for rapid adaptation to cold exposure, suggesting potential differences in capacity or rate for cold acclimation. Thus, the molecular basis for enhanced overwintering survival may be related to the elevated basal level of a number of proteins, many of which are known to confer stress tolerances. These findings are presented and overlaid with a LFQP shotgun analysis and microarray analysis. This study presents the largest quantitative proteomic data-set for strawberry crown tissue during cold exposure to date. Through the comparison of these cultivars that differ in freezing tolerance, proteins that may contribute to cold tolerance but lack significant cold induction were revealed.