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
Mathias Pasquali Erik Lysøe Publikasjonsforfatter Keong Seong Jon Menke J. Xu H. Corby KistlerSammendrag
To understand mycotoxin accumulation and the infection cycle of the wheat head blight pathogen Fusarium graminearum sensu stricto,fungal gene expression profiles were monitored during plant infection. Strains containing mutations in genes for three transcription factors were found to control deoxynivalenol (DON) accumulation in planta and pathogenicity. Expression profiles were compared between wildtype and these mutants during infection of wheat. Mutants deleted for the StuA gene were greatly decreased in sporulation and produced no perithecia in culture. Unlike "stuA mutants in F. oxysporum, F. graminearum "stuA mutants were greatly reduced in pathogenicity. Reduced pathogenicity may be due to decreased DON levels in planta, which in the mutant were
Forfattere
Morten GuntherSammendrag
http://www.forskning.no/artikler/2008/april/179160
Forfattere
Marit Larsen Sekse Sonja KlemsdalSammendrag
The apple fruit moth (Argyresthia conjugella) is a serious pest in apples. It is a specialist seed predator of rowan, but the females will lay eggs on apples when rowan berries are scarce. Olfaction is important for many insect species in locating host plants. The odorant detection results from the association of odorous ligands with specific olfactory receptors, which are located in the membrane of the olfactory neurons. The aim of this work is to identify and characterize the odorant receptor genes and the genes involved in the regulation of the circadian olfactory response rhythm in the female apple fruit moth. In order to identify ORs, and other genes involved in olfaction, in the apple fruit moth a library of mRNA up-regulated in the antenna compared to the legs was made using subtractive hybridization. So far 37 of the clones containing sequences that were found to be up-regulated in the antenna, out of in total 1045 clones, have been sequenced. BLAST searches were performed (BLASTx and BLASTn) to try to identify the transcripts. Those sequences that did not give a useful hit in the blast searches were translated to protein sequences in all six reading frames and the possible protein sequences were investigated for the presence of trans-membrane domains. The blast searches yielded useful hits for most of the sequences. 20 sequences were assigned to be probable odorant binding proteins and these seem to represent 12 different genes. Seven sequences were assigned to be glutathione S-transferases and 1 sequence were assigned to be cytochrome P450. Seven sequences gave no useful hits in the blast searches. These sequences seemed to represent 4 different genes and 2 of these have were predicted to contain transmembrane domains. These are possible odorant receptors.
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag
Forfattere
Fykse Haldor Haldor FykseSammendrag
In stockless organic cereal systems undersowing a legume shortly after sowing of cereals is a commonly used practice. Nitrogen supply as well as retarded growth of annual weeds is mentioned as benefits of such use of legumes in cropping systems. There is, however, limited knowledge on the influence of undersown cover crops on the growth of perennial weeds. This issue was addressed in a field experiment (#1) at Ås in South-eastern Norway. Furthermore, a second series of field experiments (#2) aimed at investigating the influence of (i) time of ploughing and (ii) that of black fallow. To obtain a field (#1) with uniform distribution of the perennial weed species, root fragments of Cirsium arvense (L.) Scop. and Sonchus arvensis L. and rhizomes of Elymus repens (L.) Mould., were transplanted by hand in the spring of 2002. The experiment, designed as a split-plot with 3 replicates, was initiated in 2003 and continued until the autumn of 2006. Oat undersown with red clover versus oat alone composed each year the two main plot treatments, except in 2006, in which the whole field was seeded to oat without red clover. Each mean plot was divided into four sub-plots with mechanical treatments in autumn: 1) untreated control; 2) mowing; 3) rotary tilling and 4) shallow ploughing plus harrowing. The autumn treatments were only carried out in 2004 and 2005. The number of weeds was counted at different dates throughout the growing season, and the weed biomass was assessed just before harvest. Preliminary results showed that red clover undersown in oat, compared to oat alone, had limited and in most cases insignificant effects on biomass and number of shoots of all investigated species. No significant interaction between red clover and mechanical treatments in autumn was found. Shallow ploughing suppressed E. repens most, followed by rotary tilling, mowing and untreated, in that order. On S. arvensis, mowing showed the best control, and rotary tilling the poorest. On C. arvense, significant differences between treatments were detected only in 2005, when rotary tilling and shallow ploughing reduced the weed biomass significantly compared to the untreated control.In the second experiment series (#2) C. arvense, S. arvensis and E. repens are subjected to the following treatments: 1) black fallow (soil cultivation) + ploughing in autumn 2) ploughing in autumn 3) spring ploughing, and 4) black fallow + ploughing in spring. Preliminary results from the first experimental year have shown very clear interactions between treatment and weed species: Time of ploughing did not influence the growth of E. repens significantly. On the other hand fallow in autumn suppressed this species more efficiently than fallow in spring. In general, C. arvense and S. arvensis showed the opposite behaviour regarding both time of ploughing and effect of fallow. Spring ploughing, as well as spring fallow, suppressed these species more than treatments in autumn. However, not all comparisons were significantly different. Although the results need more attention as well as new experiments before detailed recommendations can be given, the studies indicate clearly that the effect of different treatments including time of ploughing and soil cultivation periods depends on weed species.
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag
Konferansebidrag og faglig presentasjon – Fag- og markdag: Flerårig ugras i eng
Lars Olav Brandsæter
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag
Konferansebidrag og faglig presentasjon – Fag- og markdag: Flerårig ugras i eng
Lars Olav Brandsæter
Forfattere
Lars Olav BrandsæterSammendrag
Det er ikke registrert sammendrag