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.
2010
Forfattere
Maria Herrero Brita ToppeSammendrag
Den varmekjære pseudosoppen P. aphanidermatum forårsaker i Norge bare problemer i veksthus. Selv om patogenet ikke representerer noe problem på friland, vet vi at det kan overleve og formere seg i norsk klima. Under visse omstendigheter kan P.aphanidermatum angripe bjørk, og sannsynligvis andre planter i norsk vegetasjon.
Forfattere
Brita Toppe Maria HerreroSammendrag
I perioden 2006-2009 er det i norske gartnerier gjenomfort registrering av soppsjukdommar i begonia (Begonia x hiemális og Begonia x cheimántha). Både kjente og nye patogen er påvist. Spesielt store utfall er registrert ved åtak av to nye arter: Fusarium foetans og Phytophthora taxon niederhauserii
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Phytophthora cactorum, den sopp-lignende skadegjøreren som forårsaker kronråte i jordbær, kan overleve i mange år i jorda og det er ingen god måte å bli kvitt skadegjøreren på når den har kommet inn i et felt eller en planteskole. Smittede planter trenger ikke umiddelbart å vise symptomer, noe som gjør skadegjøreren enda mer vanskelig å hanskes med. Selv om det er variasjon i mottakelighet, er så godt som alle jordbærsorter i kommersiell bruk, mottakelige. Vi vet imidlertid at resistente varianter finnes innenfor jordbæras nære slektninger, foreldreartene Fragaria virginiana og Fragaria chiloensis. Det er mye uklarhet omkring hva som ligger bak forskjeller i kronråteresistens, og siden en slik forståelse er viktig for håndteringen i en foredlingssammenheng, ønsker vi å undersøke dette. Jordbæra (Fragaria x ananassa) og dens nevnte foreldrearter er imidlertid oktoploide - de har 8 sett kromosomer - noe som gjør dem vanskelig å bruke i genetiske studier. Vi, og mange andre forskergrupper, har derfor valgt å fokusere på en enklere modellplante for å finne basiskunnskap som vi i ettertid håper å kunne overføre til de dyrkede jordbæra.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Gunn Mari Strømeng Andrew Dobson Abdelhameed Elameen Sonja S. Klemsdal Jorunn Børve Arne Stensvand Thomas SundelinSammendrag
Artikkelen forteller om Colletotrichum acutatum i norsk jordbærproduksjon, om vertplanter for soppen, om genetiske analyser av soppisolater fra ulike vertplanter og smitteforsøk i jordbær og kirsebær.
Forfattere
Arne Hermansen Grete Lund Elisa Gauslå Abdelhameed Elameen Ragnhild Nærstad Sonja KlemsdalSammendrag
Det er ikke registrert sammendrag
Sammendrag
We have recently found that Norway spruce (Picea abies (L.) Karst.) can rapidly adjust its adaptive performance, probably through an epigenetic mechanism. This appears to employ a kind of long-term memory of temperature sum and (probably) photoperiod from the time of its embryo development. In our research we made identical controlled crosses and produced seed lots under controlled temperature and day-length conditions and later observed phenology, growth and hardiness traits in the progenies. It was repeatedly found that temperature conditions during seed set, in particular, influence the phenotypes of the offspring; seedlings from seeds produced under warm conditions have later terminal bud set and reduced autumn frost hardiness than those from seed produced under colder conditions, and thus perform like a more southern provenance. When embryonic clones were derived from mature zygotic embryos and were cultured at different temperatures, the plants cultured under warm in vitro temperature were the last to set bud and grew taller than those cultured at lower temperatures. Progenies produced in Norway by Central European mother trees had a bud set curve skewed towards that of the local Norwegian performance. A comparison of the performance of seedlings from seeds collected in the same provenance regions in 1970 and 2006 shows that the more recent seed lots consistently produce taller seedlings with a later bud set, probably due to higher temperatures during seed production in 2006. The effect of reproductive environment has been shown to persist for years. It mimics the variation between provenances from different latitudes and altitudes and may explain much of the observed variability in bud set and early height growth between natural populations of Norway spruce. The observed phenomenon suggests an epigenetic mechanism in the developing embryo, either zygotic or somatic, that senses environmental signals such as temperature and influences adaptive traits. Research is underway to understand the molecular basis of this mechanism. We will discuss the implications of this epigenetic phenomenon for the interpretation of provenance differences, for tree breeding and for its possible role in adaptation to climate change.
Sammendrag
We monitored the effects of the drought stress on 20-year old clones of Norway spruce (Picea abies) by using a range of instrumental methods. On two experimental plots (Hoxmark, Norway, 59°40\"14`N, 10°47\"36`E) the drought was induced in a period between May and October 2009 by removing the throughfall using the rain shelters and trenching. We collected data on soil moisture, stem and branch sap flow, xylem diameter, anatomical and calorimetric analysis of the needles, fine root biomass and dynamics and resistance to pathogens. Standard meteorological data were collected locally throughout the whole period. Here we present the preliminary analysis of sap flow and xylem diameter in a period 1-17 august 2009. The sap flow was measured on stems in the breast height by using the method of stem tissue heat balance (THB, EMS Brno). The values were measured once in 2 minutes and saved as the average of 10 minutes. The fluctuations in xylem diameter was monitored by using the automatic dendrometers DR26 (EMS Brno). We evaluated both diurnal and seasonal dynamics. Preliminary results show a significant difference in shape of diurnal curves of transpiration as well as different time lag among the sap flow and the potential evapo-transpiration. Also the differences in diurnal dynamics of the stem circumference suggested different xylem water potential in stressed and control trees. In the drought-stressed trees the diurnal fluctuation in stem diameter was about 4 times higher and the total stem increment one third lower, com-pared to the control trees.