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.
1993
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Jens Viktor Nørgaard Valerie Duran Øystein Johnsen Peter Krogstrup Snorri Baldursson Sara von ArnoldAbstract
Two sets, containing 9 and 72 embryogenic cell lines of Picea abies (L.) Karst., were tested for cryotolerance using a standard two-step cryopreservation protocol. Eight and 69 cell lines, respectively, survived freezing in all or some of the trials. A strong effect of cell line on regrowth after freezing was demonstrated in both sets. Culture morphology and maturation competence of the nine cell lines was unaffected by freezing and were not correlated to cryotolerance. In the 72 cell lines originating from seeds of five full-sib families, selected from a progeny test for their widely different autumn frost hardiness, a family effect on cryotolerance was observed. This effect was not related to physiological characters (ability to form embryogenic cultures and mature somatic embryos, autumn frost hardiness).
Authors
Knut J. Huse Kåre Olav VennAbstract
No abstract has been registered
Authors
Knut J. Huse Kåre Olav VennAbstract
No abstract has been registered
Authors
Morten Løber Eyvind NygaardAbstract
No abstract has been registered
Authors
Fred Midtgaard Ove SørlibråtenAbstract
No abstract has been registered
1992
Abstract
No abstract has been registered
Authors
Erik ChristiansenAbstract
The defence of Norway spruce against a combined attack of the bark beetle Ips typographus and its associated blue-stain fungi is based upon a) constitutive resin stored in ducts of the bark and sapwood, and b) induced resinosis in reaction zones surrounding the point of infection. Empirically, beetle epidemics are associated with external stresses, drought being a particularly prominent factor. An attempt was made to mechanistically explain the apparent link between drought and infestations, through studying after-effects of drought on the induced defence in stressed trees. In the field, 3-5.5 m tall trees were exposed to artificial drought over three growth seasons to investigate whether this treatment would predispose them to fungal infection in a fourth season when drought was absent. Pre-dawn xylem water potentials down to -1.85 MPa and a considerable foliage depletion were recorded. In the fourth season, the trees were inoculated with Ophiostoma polonicum, a pathogenic associate of Ips typographus. No difference in susceptibility could be seen between drought stressed trees and unstressed controls. Carbohydrate concentrations of foliage and branch bark were slightly enhanced and mineral nutrient concentrations strongly reduced in stressed trees.
Authors
Dan AamlidAbstract
No abstract has been registered
Authors
Anita JensenAbstract
No abstract has been registered