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.
2008
Forfattere
Harald Kvaalen Øystein JohnsenSammendrag
It has been shown previously that height growth and bud phenology are influenced by the temperature during zygotic embryogenesis in Picea abies.To test whether this phenomenon operates within individual plants, clones produced through somatic embryogenesis were used. Seeds were from a full-sib family produced in both a cold (outdoor) and a warm (inside a glasshouse) environment. Embryogenic clones derived from mature zygotic embryos from both crossing environments were cultured at 18, 23 and 28 during the proliferation and embryo maturation steps.After the second growing season in a glasshouse, plants from the warm seed production environment were taller and had significantly later bud set. For the first time, it is also shown that plants are influenced by the in vitro temperature during somatic embryo development. The warmer the temperature, the later the plants formed terminal buds. The differences were similar to those produced by a provenance separation of 4-6 degrees of latitude.The results indicate that there exists a mechanism in P. abies that operates during embryo development and adjusts the timing of bud set in accordance with the temperature conditions in which the mother tree lives. This in turn counteracts negative effects of gene flow among populations located along altitudinal and latitudinal gradients.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Jan-Ole Skage Åge ØstgårdSammendrag
Norsk institutt for skog og landskap i Bergen plantet våren 1999 ut åtte forsøk med omkring 50.000 barrotsplanter fra 76 provenienser av fjelledelgran (Abies lasiocarpa) og korkedelgran (Abies lasiocarpa var.arizonica). To av forsøkene er imidlertid blitt nedlagt pga gjentatte angrep av rustsopp, vårfrost og for dårlig jordsmonn. I de gjenværende seks forsøkene har plantene etablert seg meget godt og overlevd godt. Etter seks overvintringer og sju vekstsesonger (2005) hadde forsøkene i gjennomsnitt 80 % overlevelse og en middelhøyde på 91 cm. Provenienser fra Oregon hadde i gjennomsnitt høyest overlevelse, mens provenienser fra Arizona hadde lavest overlevelse. Provenienser fra British Columbia hadde størst høydevekst, mens provenienser fra Colorado hadde minst vekst. Provenienser fra British Columbia er vurdert til å gi det høyeste juletreutbyttet, mens provenienser fra Colorado er vurdert til det laveste utbyttet. De beste proveniensene med høyest juletreutbytte er Spring Mt., Cunningham Creek, Grizzly Lake og Inzana Lake, alle fra British Columbia i Canada. Proveniensen Spring Mt., hadde faktisk høyest utbytte i fire av seks forsøk. Etter noen flere vekstsesonger kan imidlertid andre provenienser bli rangerte som bedre provenienser. Resultatene for juletreutbytte må derfor se på som foreløpige etter sju vekstsesonger.
Forfattere
Nadeem Yaqoob Carl Gunnar Fossdal Bao Dzung Diep Halvor SolheimSammendrag
Due to the great economic losses caused by the root and butt-rot pathogen Heterobasidion annosum, developments of efficient control measures are warranted. H. annosum a necrotroph colonize the Norway spruce from inside and is responsible of 10-13 millions Euros losses in Norway alone. Considerable clonal variation has been recorded for Norway spruce in resistance towards H. annosum, but the defence mechanisms contributing to host resistance remain poorly understood. The recent genome sequencing of Populus has made the genus a model to facilitate tree genetics. Genome-wide transcript profiling of Populus tremula upon pathogen attack will now be used, and homologues of Norway spruce genes to defence genes up-regulated in Populus will be identified. Populus-Phellinus tremula pathosystem is selected as P. tremula behaves like H. annosum.
Forfattere
Jan Stenlid Åke Olson Kerstin Dalman Magnus Karlsson Mikael Brandström Karl Lundén Carl Gunnar Fossdal Matteo Garbelotto Frederick AsiegbuSammendrag
Heterobasidion annosum s.l. causes a devastating root rot in conifer plantations and natural forests throughout the northern hemisphere. The genome sequencing of H. annosum will provide the first comprehensive genetic information on a plant pathogenic homobasidiomycete allowing for new insights into plant-microbe interactions with trees, in particular conifers. It is important to broaden the taxonomic base for understanding the mechanisms of plant-microbe interactions, studying genes and proteins involved, and identifying pathogenicity determinants. Comparative genomics of plant pathogens with a gradient of taxonomic relatedness to H. annosum will help to understand the evolution of such factors. The project involves resequencing of several species in the H. annosum species complex including pathogenic and non-pathogenic species. Comparisons can also be made with fungi with different nutritional relations to plants; necrotrophic, biotrophic and mycorrhizal mutualist. The project integrates genetic approaches e.g QTL mapping with comparative genomics. Data bases generated on genes under positive selection in the sequenced genomes will be compared with candidate genes derived from published QTL mapping and EST-projects but also known pathogenicity factors in other pathosystems.
Forfattere
Lone Ross Gobakken Mats WestinSammendrag
Modified wood has potential for above ground use, but surface treatment might be a request in such applications. Three coating systems were applied on furfurylated Scots pine, acetylated Scots pine, heat treated Scots pine, oil heat treated Scots pine, heat treated Norway spruce, and eight reference wood substrates and exposed outdoors to evaluate their ability to resist surface mould. Samples of the surface were taken for fungal identification to examine any relationship between treatment and fungal species. Both water-borne and solvent-borne coatings with various fungicides were included and the test was carried out according to EN 927-3. The degree of mould growth mainly varied with time and type of paint. Of the modified wood substrates furfurylated Scots pine had the lowest degree of mould growth and acetylated pine had the highest after 3.5 years. A brown semi-transparent acrylic paint had the lowest degree of mould growth after year 1, year 2.5 and year 3.5. Larch heartwood, copper-organic preserved pine and pine heartwood performed best as wood substrates. No differential patterns in susceptibility to various fungal species were detected on the surface of the coated wood substrates Aureobasidium pullulans was the dominating species on all the wood substrates.
Forfattere
Nina Hovden Sæther Øystein Havrevoll Odd VangenSammendrag
Possible differences in gross and net feed balance and feed efficiency between two cattle breeds were studied. The “old” Black Sided Trønderfe and Nordlandsfe (STN) breed has hardly been selected for production traits the last decades due to a small population (800) while and the modern Norwegian Red (NR) breed (230 000) has been bred according to a modern breeding programme with genetic improvements in milk, growth, health and fertility. The study was done on lactating cows in three indoor feeding periods; ten cows in each breed group, fed roughage ad-lib and an adjusted level of concentrates. Feed intake, milk yield and -quality were recorded every week, and live weight was recorded every month. The gross energy balance was defined as energy intake subtracted by energy in produced milk, while the gross energy efficiency was computed by dividing energy in produced milk by energy intake. At the net energy level it was adjusted for energy loss or release from body tissue gain or loss. The results show that in spite of the large difference in production level, there were no breed differences in energy balance, neither at the gross nor at the net level. However, the NR was significantly more efficient when comparing gross feed efficiency, but there were no breed differences in net feed efficiency.
Sammendrag
The European pine sawfly Neodiprion sertifer is a widely distributed defoliator of pines that can cause substantial growth losses over extensive areas. It attacks most species of twoneedle pines in its distribution area, and have occasional short-lived outbreaks that may cover up to 200.000 ha. In Norway we have had outbreak populations in the eastern part of the country since 2004, and in an ongoing research project we are evaluating aerial application of the Neodiprion sertifer nuclear polyhedrosis virus (NsNPV) to control Neodiprion sertifer....
Forfattere
Paal KrokeneSammendrag
Combined bark beetle-fungus attacks are a key factor in conifer ecosystems in the Northern Hemisphere, where they regularly cause massive tree mortality. Central to the success of the bark beetle-fungus complex is the fact that bark beetles are among the few insects that are capable of breaching the potent anatomical and chemical defenses of healthy tree stems.....
Sammendrag
Seed production in Norway spruce (Picea abies) seed orchards may be severely reduced by insects attacking cones and seeds. Insects in several orders and genera are responsible for the damage, and at present there are no effective and environmentally acceptable control options. Studies in Sweden have shown promising results with spraying Bt (Bacillus thuringiensis var. kurstaki x aizawai) against species of Lepidoptera, but for other pests other control methods must be developed....