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.
2000
Forfattere
D. Gaudet A Laroche Åshild Ergon J. MullinSammendrag
Exposure of winter wheat to pre-hardening (20°C) and hardening (2°C) growth temperatures for different intervals under controlled environment conditions affected the nature and quantity of simple and complex carbohydrates in six cultivars differing in resistance to snow mould. The highest levels of total simple sugars were observed following exposure of plants to hardening temperatures for one week followed by a stabilisation or decline following 3 or 6 weeks exposure to 2°C. Fructan levels increased rapidly following 3 and 6 weeks exposure to 2°C. In younger plants grown for 2 weeks at 20°C and hardened for 6 weeks, 10-37% (ave. 20%) of crown dry weights existed as fructans compared with 24-47% (ave. 39%) in crowns of older plants grown for 6 weeks at 20°C and similarly hardened. Fructans comprised 75-82% of all soluble carbohydrates regardless of plant age prior to hardening. The average degree of polymerization increased from DP3-4 following one week hardening to DP9-11 following 6 weeks hardening and was significantly higher in hardened older plants than in hardened young plants. These results are discussed in relation to the form of snow mould resistance that increases with plant age in winter cereals.
Forfattere
D. Gaudet A. Laroche M. Frick J. Davoren B. Puchalski Åshild ErgonSammendrag
The pattern of expression of the pathogenesis-related (PR) proteins PR-1, chitinase, b-1,3-glucanase, and peroxidase, and phenylalanine ammonia lyase (PAL) transcripts was studied in five winter wheat cultivars differing in resistance to snow mould, under controlled conditions following growth at 20°C, during hardening at 2°C and dehardening at 20°C. The expression of these transcripts was also studied in two cultivars of winter wheat under natural conditions during autumn, winter, and early spring of 1997-98 at a field site in Lethbridge. The relative abundance of transcripts was similar in both the field and controlled environment studies: chitinase was the most abundant transcript followed by PAL, b-1,3-glucanase, PR-1 and peroxidase. Under field conditions, all PR-protein transcripts exhibited the same basic pattern of expression during the autumn, winter and spring sampling dates; transcripts were expressed during the late autumn, reached high levels by mid-winter, then dcreased before reaching maximum leves during the spring. Conversely, PAL expression was low or absent in autumn, reached the highest levels by mid-winter, and then gradually decreased during the spring. Under controlled environment conditions, transcripts encoding for PAL and the PR-proteins, except chitinase, were constitutively expressed to varying extents in the unhardened treatments. The general pattern of expression fell into two groups: (1) transcripts of chitinase, b-1,3-glucanase, and PAL, were weakly expressed in the unhardened treatments, strongly up-regulated following exposure to hardening conditions, and disappeared or remained stable following dehardening; and, (2) PR-1 and peroxidase transcripts were down-regulated upon initial exposure to hardening, increased slightly following prolonged exposure to hardening conditions, and remained stable during dehardening. Under controlled conditions, the pattern of expression of any of the PR-proteins did not appear to be associated with known genotypic levels of snow mould resistance among cultivars but, under field conditions, expression levels were generally higher for all PR-proteins in the snow mould resistant cultivar, CI14106 than in the moderately susceptible cultivar, Norstar. These results demonstrate that different PR-protein and PAL transcripts in winter wheat are expressed in the field throughout the winter and are differentially induced in response to exposure of plants to low, hardening temperatures under both field and controlled environment conditions.
Forfattere
H.M. Wang Arild SlettenSammendrag
Det er ikke registrert sammendrag
Forfattere
Brita Toppe K. ThinggardSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Olav Brandsæter T. Smeby Anne-Marte Tronsmo Jan NetlandSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Kjersti Bakken Astrid JohansenSammendrag
An organic crop rotation system simulating a dairy farm with 1.0 cow per ha has been run for six years with undersown barley, three year leys, swede and oats. The fodder supply at the farm has been evaluated with the presumptions that 70 % of the energy requirement of the cows should be covered by roughages and that the yearly milk production was 5000 kg per cow. The requirement for roughages was covered by the farm itself in five out of six years, whereas the yields of barley and oats were all years too low to cover the proportion of energy to be supplied from other sources. Due to a low nitrogen content, the protein deficit of the fodder produced in the system was higher than the energy deficit, and considerable amounts of fodder rich in proteins would have to be imported unless the stocking rate and/or the milk production per cow is lowered.
Forfattere
D.M.F. van Aalten B. Synstad May Bente Brurberg E. Hough B. Riise V.G.H. Eijsink R.K. WierengaSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Kjersti BakkenSammendrag
Ein rapporterer resultat frå feltforsøk med ulike typar steinmjøl og avgang frå bergverksindustrien som kaliumkjelder for engvekstar
Forfattere
P. Dennis G.L.A. Fry Arild AndersenSammendrag
Faunaen av kortvinger og løpebiller ble undersøkt i kornåkre og tilgrensende områder. Migrasjon av den enkelte art mellom åker og åkerkant ble kartlagt ved bruk av avlange fallfeller (såkalte "guttertraps") og jordprøver.
Forfattere
Arild Andersen Ragnar EltunSammendrag
Løpebille- og kortvingefaunaen ble registrert i langvarige forsøk (6-8 år) ved omlegging til økologisk dyrking på Apelsvoll og Ås. Det var en positiv effekt på mange løpebiller, bl.a. Harpalus rufipes og mange arter i slektene Amara, Bembidion og Pterostichus, dessuten på kortvingearten Aleochara bipustulata. Økt mengde ugras kan forklare deler av økningen. Det var en negativ effekt på mange kortvingearter, bl.a. Philonthus cognatus og Tachyporus-arter, dessuten på løpebillearten Trechus quadristriatus.