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.
2012
Authors
Jørn Henrik Sønstebø Mari Mette TollefsrudAbstract
Background: The conifer tree Abies lasiocarpa, is native to North America with a distribution range from Alaska in the north to Arizona and New Mexico in the south. The southern populations partly belong to the variety A. lasiocarpa var. arizonica, which has a distinct morphology. A. lasiocarpa is an important species for Christmas tree production in Norway and there is an increasing demand for seeds from proveniences known to produce high quality Christmas trees. Currently, seeds are imported from natural stands in the US and Canada or collected from plantations in Norway with unknown origin, but which are known to produce high quality trees. To increase the harvest potential of seeds in A. lasiocarpa both in natural stands and in seed production stands in Norway, it is important to know the population genetic structure in North America and identify the origin of the current seed producing trees in Norway. Population genetic structures will be used to identify new potential seed collection areas in North America.Main objectives: Investigate population genetic structure across the distribution range of A. lasiocarpa. Characterize genetic diversity in north American provenances and seed bearing stands in Norway. Assign Norwegian provenances to north American provenances in order to identify their origin and new potential seed collection zones.
Abstract
The ascomycete fungus Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea) is responsible for ash dieback currently expanding over large parts of Europe. Our objective was to investigate the genetic structure of H. pseudoalbidus and to examine its relationship to the species H. albidus, known as a saprotroph. The study comprised 181 isolates of H. pseudoalbidus collected within the diseased area, 17 H. albidus isolates from six apothecia, collected outside the diseased area in Norway, and nine apothecia of H. pseudoalbidus collected in Sweden. By analysis of microsatellite markers developed for this study, combined with AP-PCR using the M13 primer, we demonstrated sexual heterothally in H. pseudoalbidus, detected high gene flow and low geographic structure of the H. pseudoalbidus population and found indications of a founder effect. Also, substantial genetic differences were detected between the two species of fungi; only four of seven microsatellite markers developed for H. pseudoalbidus were amplified for H. albidus, and no alleles were shared among the species. Furthermore, AP-PCR banding patterns were distinctly different for the two species. We conclude that even though the two fungi have a similar habitat and are morphologically virtually identical, they do not share a recent common ancestor.
Authors
Liv Guri Velle Vigdis VandvikAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Ricardo HolgadoAbstract
No abstract has been registered
Authors
Arne Hermansen D. Lu Greg ForbesAbstract
No abstract has been registered
Authors
Arne HermansenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Erik J. JonerAbstract
No abstract has been registered