Berit Nordskog

Forsker

Divisjon for bioteknologi og plantehelse

Soppsjukdommer

(+47) 920 39 087
berit.nordskog@nibio.no

Sted
Ås - Bygg H7

Besøksadresse
Høgskoleveien 7, 1433 Ås

Til dokument

Sammendrag

Sclerotinia species are important fungal pathogens of a wide range of crops and wild host plants. While the biology and population structure of Sclerotinia sclerotiorum has been well-studied, little information is available for the related species S. subarctica. In this study, Sclerotinia isolates were collected from different crop plants and the wild host Ranuculus ficaria (meadow buttercup) in England, Scotland, and Norway to determine the incidence of Sclerotinia subarctica and examine the population structure of this pathogen for the first time. Incidence was very low in England, comprising only 4.3% of isolates while moderate and high incidence of S. subarctica was identified in Scotland and Norway, comprising 18.3 and 48.0% of isolates respectively. Characterization with eight microsatellite markers identified 75 haplotypes within a total of 157 isolates over the three countries with a few haplotypes in Scotland and Norway sampled at a higher frequency than the rest across multiple locations and host plants. In total, eight microsatellite haplotypes were shared between Scotland and Norway while none were shared with England. Bayesian and principal component analyses revealed common ancestry and clustering of Scottish and Norwegian S. subarctica isolates while English isolates were assigned to a separate population cluster and exhibited low diversity indicative of isolation. Population structure was also examined for S. sclerotiorum isolates from England, Scotland, Norway, and Australia using microsatellite data, including some from a previous study in England. In total, 484 haplotypes were identified within 800 S. sclerotiorum isolates with just 15 shared between England and Scotland and none shared between any other countries. Bayesian and principal component analyses revealed a common ancestry and clustering of the English and Scottish isolates while Norwegian and Australian isolates were assigned to separate clusters. Furthermore, sequencing part of the intergenic spacer (IGS) region of the rRNA gene resulted in 26 IGS haplotypes within 870 S. sclerotiorum isolates, nine of which had not been previously identified and two of which were also widely distributed across different countries. S. subarctica therefore has a multiclonal population structure similar to S. sclerotiorum, but has a different ancestry and distribution across England, Scotland, and Norway.

Sammendrag

High concentrations of the mycotoxin deoxynivalenol (DON), produced by Fusarium graminearum have occurred frequently in Norwegian oats recently. Early prediction of DON levels is important for farmers, authorities and the Cereal Industry. In this study, the main weather factors influencing mycotoxin accumulation were identified and two models to predict the risk of DON in oat grains in Norway were developed: (1) as a warning system for farmers to decide if and when to treat with fungicide, and (2) for authorities and industry to use at harvest to identify potential food safety problems. Oat grain samples from farmers’ fields were collected together with weather data (2004–2013). A mathematical model was developed and used to estimate phenology windows of growth stages in oats (tillering, flowering etc.). Weather summarisations were then calculated within these windows, and the Spearman rank correlation factor calculated between DON-contamination in oats at harvest and the weather summarisations for each phenological window. DON contamination was most clearly associated with the weather conditions around flowering and close to harvest. Warm, rainy and humid weather during and around flowering increased the risk of DON accumulation in oats, as did dry periods during germination/seedling growth and tillering. Prior to harvest, warm and humid weather conditions followed by cool and dry conditions were associated with a decreased risk of DON accumulation. A prediction model, including only pre-flowering weather conditions, adequately forecasted risk of DON contamination in oat, and can aid in decisions about fungicide treatments.

Sammendrag

En rekordvarm september markerte avslutningen på en vekstsesong som har vært litt varmere enn normalen i det meste av landet. Nedbør har imidlertid vært ujevnt fordelt gjennom sesongen, med store geogra ske forskjeller. Spesielt på Vestlandet var det vått store deler av sommeren.

Sammendrag

Sommeren 2015 vil bli husket som kald og våt, med store nedbørmengder i enkelte perioder. Regnet på Østlandet fra midten av august vil bli husket spesielt godt. Til tross for dette ser kornavlingene ut til å bli like høye i 2015 som i 2014.

Sammendrag

Gårdsvarsling gjør det mulig å beregne lokalt tilpassede plantevernvarsler ved bruk av værvarsel og radarmåling av nedbør. Vanligvis beregnes plantevernvarsler på grunnlag av data fra værstasjoner, men mange gårdsbruk ligger langt unna nærmeste målepunkt. For disse brukene vil varsler basert på værvarsler og radarmålt nedbør være et godt alternativ. Gårdsvarsler tilpasset det enkelte gårdsbruk vil derfor øke nytteverdien av varslingstjenesten innen planteskadegjørere (VIPS) for mange dyrkere.

Sammendrag

Dette er en kort gjennomgang av været i vekstsesongen 2011 basert på data registrert ved Bioforsks værstasjoner og noen detaljer hentet fra klimatologiske oversikter utgitt av Meteorologisk institutt. Temperatur- og nedbørdata viser at det i perioden mai til september var varmere og våtere enn normalt de fleste steder. Enkelte stasjoner på sentrale deler av Østlandet hadde litt lavere varmesum enn normalt, mens det ved våre stasjoner nord for Bodø var betydelig tørrere enn normalt.