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.
1993
Forfattere
Oddvar SkreSammendrag
Det er ikke registrert sammendrag
Forfattere
Erik NæssetSammendrag
Det er ikke registrert sammendrag
Forfattere
C. Carter Øystein AustaråSammendrag
Det er ikke registrert sammendrag
Forfattere
Tron Eid Andreas Fitje Sveinung NerstenSammendrag
Det er ikke registrert sammendrag
Forfattere
Harald Kvaalen Arild ErnstsenSammendrag
It is known that reducing the partial pressure of O2 influences the induction of somatic embryogenesis. We tested the hypothesis that O2 causes changes in the endogenous levels of exogenously supplied benzyladenine (BA) or 2,4-dichlorophenoxyacetic acid (2,4-D).Embryogenic tissue of Picea abies was incubated under reduced (2.5, 5 kPa) and ambient (21 kPa) levels of O2 for 1, 3, 7 and 11 days and the endogenous concentrations of BA and 2,4-D were measured. For all treatments the concentration of BA in the tissue increased until the third day. At day 3, the ratio of BA in the tissue relative to the initial concentration in the medium, was 3.9, 2.8 and 1.9 for tissue incubated under 2.5, 5 and 21 kPa O2, respectively. The BA concentration then declined gradually. Uptake of 2,4-D was inhibited at low O2 levels.However, 2,4-D gradually accumulated in tissue grown under hypoxia, so that high levels were reached by day 11. These shifts in the BA and 2,4-D levels also caused a transient increase in the BA to 2,4-D ratio in tissue incubated under hypoxia. Although relevant for the previously reported effects of oxygen on induction of embryogenic tissue, it is unlikely that oxygen-induced alterations in BA and 2,4-D levels alone suffice to explain these findings.
Forfattere
Lars Sandved DalenSammendrag
Det er ikke registrert sammendrag
Forfattere
Alhaji S. Jeng B. R SinghSammendrag
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Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The pathogenicity of the blue-stain fungi Leptographium wingfieldii Morelet and Ophiostoma minus (Hedgc.) H. et P. Syd. associated with the pine shoot beetle Tomicus piniperda (L.), was determined on pruned and unpruned Seots pine (Pinus sylvestris L.) trees. Both fungi killed unpruned trees when inoculated in a 60 cm wide band at a density of 800 inoculations/m2, while severely pruned trees were killed by an inoculation density of 400 inoculations/m2. Trees inoculated with L. wingfieldii died sooner after inoculation than trees inoculated with O. minus.
Forfattere
Oddvar SkreSammendrag
The measurements were carried out on excised leaf discs and intactplants by infrared gas analyser technique. The sample plants had been grown for six weeks in varying temperature, light and daylengths. The photorespiration was estimated from measurements at low oxygen level. A strong temperature acclimation effect was found on CO2 exchange rates. Long term low-temperature treatment caused a reduction in photosynthesis and its temperature optimum in all birch populations. Strong acclimation effects of light were also found. Short term (48 hours) low-temperature treatment reduced photosynthesis rates at low light levels. Mountain birch from northern or arctic populations showed relatively high net photosynthetic rates compared with southern populations.