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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

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.

Sammendrag

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.

Sammendrag

Embryogenic cultures of red spruce (Picea rubens Sarg.) and Norway spruce (Picea abies (L.) Karst.) were initiated from dissected mature zygotic embryos. The tissues were grown on either proliferation medium or maturation medium. On proliferation medium, the embryogenic tissue continued to produce early stage somatic embryos (organized meristems attached to elongated, suspensor-like cells), whereas on maturation medium fully mature embryos developed from the embryonic tissue. Analysis of polyamines in tissues grown on these two media showed that: both putrescine and spermidine concentrations were always higher in cultures grown on proliferation medium than in cultures grown on maturation mediumin both species, spermidine concentrations declined with time in the tissues grown on maturation medium spermine was present in only minute quantities and showed only a small change with time. The presence of difluoromethylomithine in the culture medium had little effect on polyamine concentration, whereas the presence of difluoromethylarginine caused a decrease in putrescine concentrations in both red spruce and Norway spruce tissues grown on proliferation medium or maturation medium.