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.
2012
Authors
Ghislain Tchoromi Tepa-Yotto Trond Hofsvang Ignace Godonou May SæthreAbstract
The solitary parasitic wasp Lysiphlebus testaceipes, is a species native to North America. The species has a broad aphid host range and has been accidentally spread or introduced as a biocontrol agent to many regions of the world. In Benin, L. testaceipes is a newly found species, and it is the dominating primary parasitoid of aphids on vegetables.
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Authors
Atle Wibe Ilze Apenite Catherine A Baroffio Anna-Karin Borg-Karlson Jerry Cross David Richard Hall Lene Sigsgaard Nina TrandemAbstract
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Atle Wibe Ilze Apenite Catherine A Baroffio Anna-Karin Borg-Karlson Jerry Cross David Richard Hall Lene Sigsgaard Nina TrandemAbstract
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Authors
Celine ReboursAbstract
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Authors
Fride Høistad ScheiAbstract
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The winter hardiness of strawberry cultivars used in perennial production systems varies greatly, although a strong linkage exists between transcriptional and metabolic changes during cold acclimation. Still, little information is available on how plant metabolism adapts to cold and freezing temperatures under natural temperature and light conditions. In order to examine the hardening process of overwintering meristematic tissue in Fragaria x ananassa, crown samples of field-grown cvs. ‘Polka’ and ‘Honeoye’ were consecutively collected over a period of 15 weeks, i.e. from the end of the season (week 35/ end August) until midwinter (week 50/ December). Samples were subjected to qGC MS metabolite profiling to assess the reconfiguration of central metabolism, and characterize the regulation of selected compatible solutes (amino acids, Krebs metabolites, sugars, polyols). Besides changes in amino acid patterns (glutamic acid, aspartic acid, and asparagine), monosaccharide levels (fructose) were strongly enhanced until the end of the acclimation period in cv. ‘Honeoye’ (180-fold compared to start control). In contrast, ‘Polka’ showed a concentration peak (36-fold) in week 47 and a decline towards week 50. Also sucrose levels were steadily enhanced throughout the cold hardening period with averagely 6-fold higher levels in ‘Honeoye’ compared to ‘Polka’, thus underscoring cultivar differences. However, both cultivars showed a clear decline in sucrose levels after week 47. Particularly, the raffinose pathway was affected leading to strongly and transiently increased levels of the precursor galactinol (week 42/ mid October) and the trisaccharide raffinose (weeks 43 to 47/ end October to mid November). While galactinol biosynthesis was obviously earlier induced in cv. ‘Polka’ (week 38) compared to ‘Honeoye’ (week 39), subsequent raffinose production and concentration peaks were clearly delayed in ‘Polka’ (week 47) in contrast to ‘Honeoye’ (week 45). Major metabolic changes in both cultivars coincided with a decrease in daylength below 14 h after week 37 (mid September), and a consistent drop below 10°C average day temperature in week 39 (end September). The effect of temperature and light conditions on metabolic cold acclimation in field-grown strawberry is discussed. Keywords: Winter hardiness, metabolite profiling, quadrupole gas chromatography-mass spectrometry (qGC-MS), temperature, light
Authors
Inger Martinussen Jens Rohloff Laura Jaakola Kajetan Trost Olavi Junttila Hely Häggman Eivind UlebergAbstract
The effects of climate on production and the quality of bilberries have been studied in a controlled phytotrone experiment using clonal material originating from Northern and Southern parts of Finland. In the experiment individual plants from two Northern clones and two Southern clones have been grown at 12° and 18°C. At each temperature 3 different light treatments have been tested; 1) 24 h natural light (long day), 2) 12 h natural light (short day) and 3) 24 h natural light with an addition of extra red light. All berries produced by each plant have been harvested at maturity and have been analyzed for several important quality parameters. The metabolic profiling results show that levels of flavonols (epicatechin and catechin), hydroxyl acids (chlorogenic acid, hydroxyl cinnamic acid), quinic acid and all analyzed carbohydrates (myo-inositol, fructose, glucose and sucrose) are highest at 12°C. On the contrary, total anthocyanins levels were highest at 18°C and this was also reflected in the results on analysis of several anthocyanins derivates with the exception of Del 3‑Ara that was significantly higher at 12°C than 18°C. Northern clones had significantly higher levels of total anthocyanins, all measured anthocyanin derivates, total phenols, malic acid and sucrose than Southern clones.