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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.

2000

Abstract

The influence of light quality on the proliferation of embryogenic tissue of three genotypes of Norway spruce (Picea abies [L.] Karst), with different capacities for mature somatic embryo production, was studied.The proliferating tissues were subjected to light from commercially available light sources: Philips TLD Warm White 36W/29, Philips TLD Blue 18W/18, Philips TLD Red 36W/15, Osram L Fluora 36W/77 and Sylvania Far Red 7080, for 18 h a day with the photon flux (PAR) at 30 mol m-2 s-1.The effect of light quality on the growth of embryogenic tissue was strongly genotype dependent. In genotype 164-4 tissue proliferation was strongly inhibited by blue and red light. Genotype 86:52 reacted in a similar way, but not as strongly as 164-4, whereas the tissue of genotype 186-3 was almost insensitive to light quality and grew fast in all light conditions.

Abstract

Three clones of Norway spruce (Picea abies) were studied for their response to mass-inoculation with the blue-stain fungus Ceratocystis polonica. The effect of different pretreatments (fungal inoculation and wounding) before mass-inoculation was investigated for their possible role in an acquired resistance reaction.Pretreated trees showed enhanced resistance to the subsequent mass-inoculation relative to control trees that received no pretreatment. Furthermore, the fungal colonization of inoculated trees was less than that of wounded trees. The phenolic content of the bark, analysed by RP-HPLC, was compared in trees receiving different treatments.Trees inoculated with C. polonica had higher average concentration of ()-catechin, taxifolin and trans-resveratrol than wounded trees. Both inoculated and wounded trees had higher average concentrations of these compounds than control trees.The effect of the phenolic extract of Norway spruce bark on the growth of the root rot fungus Heterobasidion annosum and the blue-stain fungi C. polonica and Ophiostoma penicillatum were investigated in vitro. Heterobasidion annosum was not negatively affected, and the extracts had fungistatic effects on the blue-stain fungi. The growth of O. penicillatum was more inhibited than the growth of the more aggressive C. polonica.