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.
2010
Abstract
Det er ikke registrert sammendrag
Authors
Audun Korsæth Marianne Bechmann Gustav Fystro M Kössling Jan Netland Eivind Vangdal Astrid Johansen Tor J. JohansenAbstract
Det er ikke registrert sammendrag
Authors
Anne Linn Hykkerud Jørgen A.B. Mølmann Tor J. Johansen Randi Seljåsen Josefine Skaret Gunnar BengtssonAbstract
Det er ikke registrert sammendrag
Abstract
Scenarios of climate changes indicate longer and more frequent spells of mild weather during winter in northern latitudes. De-hardening in perennial grasses could increase the risk of frost kill. In this study, the resistance to de-hardening of different grass species and cultivars was examined, and whether the resistance changes during winter or between years, was tested. In Experiment 1, two cultivars of timothy (Phleum pratense L.) and perennial ryegrass (Lolium perenne L.) of contrasting winter hardiness were grown under ambient winter conditions, transferred from the field in January and April 2006 to the laboratory for 9 d with controlled de-hardening conditions of 3°C, 9°C and 15°C. The timothy cultivars were tested at 3°C, 6°C and 9°C in a similar experiment (Experiment 2) in January 2007. De-hardening, measured as decrease in frost tolerance (LT50), was less in timothy than in perennial ryegrass and increased with increasing temperatures. The northern winter-hardy cultivar Engmo of timothy de-hardened more rapidly than the less-hardy cultivar Grindstad, but had higher initial frost tolerance in both experiments, whereas there was less difference between cultivars of perennial ryegrass in Experiment 1. Cultivar Grindstad of timothy lost all hardiness in early spring at all temperatures, whereas cultivar Engmo maintained some hardiness at 3°C. Cultivar Engmo de-hardened at a lower rate in 2007 than in 2006, in spite of similar frost tolerance at the start of de-hardening treatment in both years. This indicates that the rate of de-hardening was controlled by factors additional to the initial frost tolerance and that autumn weather conditions might be important for the resistance to de-hardening.
Authors
C. Rahn K. Zhang R. Lillywhite R Ramos J. Doltra JF De Paz Hugh Riley M. Fint C. Nendel K. Thorup Kristensen A. Pedersen F. Piro C. Firth U. Schmutz F. Rayns K. StrohmeyerAbstract
Det er ikke registrert sammendrag
Abstract
Det er ikke registrert sammendrag
Abstract
Det er ikke registrert sammendrag
Abstract
Det er ikke registrert sammendrag
Abstract
Det er ikke registrert sammendrag
Abstract
Tomato plants (Solanum lycopersicum, cv. Suzanne) were subjected to complete nutrient solution or a solution without nitrogen (N), and placed at different temperatures and light conditions to test the effects of environment on flavonoids and caffeoyl derivatives and related gene expression. N depletion during 4-8 days resulted in enhanced levels of flavonoids and caffeoyl derivatives. Anthocyanins showed pronounced increased levels when lowering the growth temperature from 24 degrees C to 18 degrees C or 12 degrees C. Flavonol levels increased when the light intensity was increased from 100 mu mol m(-2) s(-1) to 200 mu mol m(-2) s(-1) PAR. Synergistic effects of the various environmental factors were observed. The increase in content of quercetin derivatives in response to low temperatures was only found under conditions of N depletion, and especially at the higher light intensity. Expression of structural genes in the phenylpropanoid and flavonoid pathways, PAL (phenylalanine ammonia lyase), CHS (chalcone synthase), F3H (flavanone 3-hydroxylase), and FLS (flavonol synthase) increased in response to N depletion, in agreement with a corresponding increase in flavonoid and caffeoyl content. Expression of these structural genes generally also increased in response to lower temperatures. As indicated through expression studies and correlation analysis, effects of N depletion were apparently mediated through the overall regulators of the pathway the MYB transcription factor ANT1 (ANTHOCYANIN 1) and SlJAF13 (a bHLH transcription factor orthologue of petunia JAF13 and maize RED genes). A PAL gene (PAL6) was identified, and correlation analysis was compatible with PAL6 being an actively expressed gene with function in flavonoid synthesis. (C) 2009 Elsevier Ltd. All rights reserved.