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.
2021
Forfattere
Tommi Nyman Elena Papadopoulou Eeva Ylinen Saskia Wutke Craig T. Michell Ludmila Sromek Tuula Sinisalo Elena Andrievskaya Vyacheslav Alexeev Mervi KunnasrantaSammendrag
Three subspecies of the ringed seal (Pusa hispida) are found in northeastern Europe: P. h. botnica in the Baltic Sea, P. h saimensis in Lake Saimaa in Finland, and P. h. ladogensis in Lake Ladoga in Russia. We investigated the poorly-known cestode helminth communities of these closely related but ecologically divergent subspecies using COI barcode data. Our results show that, while cestodes from the Baltic Sea represent Schistocephalus solidus, all worms from the two lakes are identified as Ligula intestinalis, a species that has previously not been reported from seals. The observed shift in cestode communities appears to be driven by differential availability of intermediate fish host species in marine vs. freshwater environments. Both observed cestode species normally infect fish-eating birds, so further work is required to elucidate the health and conservation implications of cestode infections in European ringed seals, whether L. intestinalis occurs also in marine ringed seals, and whether the species is able to reproduce in seal hosts. In addition, a deep barcode divergence found within S. solidus suggests the presence of cryptic diversity under this species name.
Sammendrag
Plants with roots and soil clumps transported over long distances in plant trading can harbor plant pathogenic oomycetes, facilitating disease outbreaks that threaten ecosystems, biodiversity, and food security. Tools to detect the presence of such oomycetes with a sufficiently high throughput and broad scope are currently not part of international phytosanitary testing regimes. In this work, DNA metabarcoding targeting the internal transcribed spacer (ITS) region was employed to broadly detect and identify oomycetes present in soil from internationally shipped plants. This method was compared to traditional isolation-based detection and identification after an enrichment step. DNA metabarcoding showed widespread presence of potentially plant pathogenic Phytophthora and Pythium species in internationally transported rhizospheric soil with Pythium being the overall most abundant genus observed. Baiting, a commonly employed enrichment method for Phytophthora species, led to an increase of golden-brown algae in the soil samples, but did not increase the relative or absolute abundance of potentially plant pathogenic oomycetes. Metabarcoding of rhizospheric soil yielded DNA sequences corresponding to oomycete isolates obtained after enrichment and identified them correctly but did not always detect the isolated oomycetes in the same samples. This work provides a proof of concept and outlines necessary improvements for the use of environmental DNA (eDNA) and metabarcoding as a standalone phytosanitary assessment tool for broad detection and identification of plant pathogenic oomycetes.
Forfattere
Ida Marie Luna Fløystad Paul Eric Aspholm Katja Häkli Per John Aslaksen Anti Per Anders Eira Ann Maret Eira Johan Henrik Gaup Nikolai Pedersen Ingrid Helle Søvik Snorre Hagen Hans Geir EikenSammendrag
DNA-overvåking av brunbjørn i et totalt 650 km2 stort område i Karasjok kommune i Troms og Finnmark ble utført med hårfeller med luktstoff i 2 måneder fra juni til august i 2020. Overvåkingen ble utført i tre deler; et hårfelleprosjekt sentralt i Karasjok, et hårfelleprosjekt i Anàrjohka og et hårfelleprosjekt utført av et elgjaktlag i jaktfelt 28. Vi brukte et 5 x 5 km rutesystem med totalt 26 ruter med én hårfelle i hver rute, og der hårfellen ble flyttet etter en måned til en annen lokalitet i samme rute. I tillegg var to hårfeller plassert på geografiske punkt av elgjaktlag i 2 uker. Det ble samlet inn til sammen 58 hårprøver fra hårfellene (i tillegg til 9 ekskrementprøver). For de 16 hårfellene sentralt plassert i Karasjok var 24 av de 48 innsamlede prøvene (50 %) positive for brunbjørn i DNA-analysen ved laboratoriet på NIBIO Svanhovd. Fra disse prøvene ga 22 prøver en fullstendig identifiserende DNA-profil som viste 8 ulike bjørner (3 hannbjørn og 5 hunnbjørn). Bjørnetettheten ble estimert til 0,20 bjørn/10km2 som er i samsvar med forrige år. Totalt ble det funnet 11 ulike bjørneindivider (5 hannbjørn og 6 hunnbjørn) for de 3 hårfelleprosjektene. Av disse 11 var 9 bjørner tidligere påvist, mens 2 av bjørnene (2 hannbjørner) var nye. Hårfelleprosjektetene bidrar med unik geografisk og tidsmessig informasjon om bjørneaktivitenen i området, og 4 av de 11 påviste bjørnene var i 2020 kun påvist igjennom hårfelleprosjektene.
Forfattere
Volkmar TimmermannSammendrag
Det er ikke registrert sammendrag
Sammendrag
Across North America, forests dominated by Quercus rubra L. (northern red oak), a moderately shade-tolerant tree species, are undergoing successional replacement by shade-tolerant competitors. Under closed canopies, Q. rubra seedlings are unable to compete with these shade-tolerant species and do not recruit to upper forest strata. In Europe, natural regeneration of introduced Q. rubra is often successful despite the absence of fire, which promotes regeneration in the native range. Considering that understorey light availability is a major factor affecting recruitment of seedlings, we hypothesized that Q. rubra seedlings are more shade tolerant in the introduced range than in the native range. Morphological traits and biomass allocation patterns of seedlings indicative of shade tolerance were compared for Q. rubra and three co-occurring native species in two closed-canopy forests in the native range (Ontario, Canada) and introduced range (Baden-Württemburg, Germany). In the native range, Q. rubra allocated a greater proportion of biomass to roots, while in the introduced range, growth and allocation patterns favored the development of leaves. Q. rubra seedlings had greater annual increases in height, diameter and biomass in the introduced range. Q. rubra seedlings in the introduced range were also younger; however, they had a mean area per leaf and a total leaf area per seedling that were five times greater than seedlings in the native range. Such differences in morphological traits and allocation patterns support the hypothesis that Q. rubra expresses greater shade tolerance in the introduced range, and that natural regeneration of Q. rubra is not as limited by shade as in the native range. The ability of Q. rubra seedlings to grow faster under closed canopies in Europe may explain the discrepancy in regeneration success of this species in native and introduced ranges. Future research should confirm findings of this study over a greater geographical range in native and introduced ecosystems, and examine the genetic and environmental bases of observed differences in plant traits.
Forfattere
Mélanie Spedener Anders Nielsen Marie Vestergaard Henriksen Gunnar Austrheim Karen Marie Mathisen Barbara ZimmermannSammendrag
Det er ikke registrert sammendrag
Sammendrag
To hundre mjølkebruk i Midt-Norge blei delt i tre nesten like store grupper; 'Låg' (68 gardar), 'Medium' (67 gardar) og 'Høg' (68 garder), etter årleg tildeling av kraftfôr til mjølkekyrne for å teste effekten av kraftfôrnivå på indikatorar for miljøpåverknad og økonomisk lønsemd. Gjennomsnittleg årleg kraftfôrnivå per ku var 15,4, 18,8 og 21,7 GJ nettoenergi laktasjon (NEL) og årleg avdrått i energikorrigert mjølk (EKM) per ku var 7868, 8421 og 8906 kg i høvesvis 'Låg', ‘Medium’og ‘Høg’. Standard livsløpsanalyse og dekningsbidrag blei brukt til å bestemme indikatorar for miljøpåverknad og økonomiske resultat av mjølk- og kjøttproduksjon. Den funksjonelle eininga var mengde 2,78 MJ spiseleg energi, tilsvarande 1,0 kg EKM eller 0,42 kg kjøtt eller en kombinasjon av mjølk og kjøtt som utgjer 2,78 MJ, altså EKM ekvivalent i mjølk og kjøtt levert EKM-eq. Det globale oppvarmingspotensialet, energiintensiteten og nitrogenintensiteten var i gjennomsnitt 1,46 kg CO2- eq./kg EKM-eq., 5,61 MJ energibruk/kg EKM-eq., og 6,83 N input/N-produkt, og var ikkje forskjellig mellom gruppene. Gardar med ‘Låg’ kraftfôrtildeling brukte mindre areal av total arealbruk til dyrking av innkjøpt fôr utanfor garden enn de i ‘Høg’ (0,39 vs. 0,46 daa/daa), men det totale arealet som blei brukt per kg EKM-eq. var større ('Låg' 3,24 vs. 'Høg' 2,84 m2/kg EKM-eq.). Dekningsbidraget per kg EKM-eq. levert var i gjennomsnitt høgare på 'Låg' gardar (6,57 NOK/kg EKM-eq.) enn 'Medium' (6,04 NOK/ kg EKM-eq.) og 'Høg' (5,73 NOK/kg ECM-eq.). Vår analyse viser at høgare kraftfôrnivå ikkje alltid gir mindre global oppvarmingspotensiale og mengd fossil energi per kg mjølk og kjøtt produsert samanlikna med lågare kraftfôrnivå.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Plant virus eradication is a prerequisite for the use of virus-free propagules for sustainable crop production. In contrast, virus preservation is required for all types of applied and basic research of viruses. Shoot tip cryopreservation can act as a double-edged strategy, facilitating either virus eradication or virus preservation in cryoderived plants. Here, we tested the efficacies of shoot tip cryopreservation for virus eradication and preservation in shallot (Allium cepa var. aggregatum). In vitro stock shallot shoots infected with onion yellow dwarf virus (OYDV) and shallot latent virus were thermotreated for 0, 2, and 4 weeks at a constant temperature of 36℃ before shoot tip cryopreservation. Results showed that viruses were preserved in recovered shoots when thermotherapy was not applied. Although thermotherapy lowered the regrowth levels of cryotreated shoot tips, the efficiency of virus eradication increased from 5% to 54%. Immunolocalization of OYDV and histological observation of cryotreated shoot tips showed the high frequency of virus preservation was due to the viral invasion of cells close to the apical meristem and the high proportion of cells surviving. Four weeks of thermotherapy drastically decreased the distribution of OYDV, as well as the percentage of surviving cells within the shoot tips, thereby promoting virus eradication. Virus-free plants obtained from combining thermotherapy with cryotherapy showed significantly improved vegetative growth and bulb production. The present study reports how thermotherapy can act as a trigger to facilitate either the safe preservation of Allium viruses or the production of virus-free shallot plants.
Sammendrag
Det er ikke registrert sammendrag