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
Sammendrag
The last few years, increasing levels of DON (deoxynivalenol) have been recorded in Norwegian cereals, particularly in oats. In the same period, increased occurrence of F. graminearum has been reported in Norway as well as in the Western part of Europe. There may be several reasons for this change: Climate change, altered distribution of cereal cultivars, pathogen adaptation to cooler regions etc. We aim to clarify whether the increasing occurrence of F. graminearum in Norwegian cereals is connected to a change in the distribution of genotypes of this species. Fifty `old" F. graminearum isolates collected from Norwegian grown cereals during the 1990s will be compared to a similar number of `new" isolates collected in recent years (2005-2007). Isolates from Germany, Russia, Finland and the US will be used for comparisons. The genetic diversity of these about 110 isolates (50 `new", 50 `old" and 10 non-Norwegian isolates) will be investigated by AFLP (amplified fragment length polymorphism). These isolates will also be identified phylogenetically and characterised to chemotype. In addition, some selected isolates will be assessed for aggressiveness on wheat and specific characters potentially important for fungal distribution such as in vitro growth rate, spore production and perithecia formation.
Forfattere
Kerry O\"Donnell Todd J. Ward Dereje Aberra T. Aoki H. Corby Kistler Åsmund Bjørnstad Sonja Sletner KlemsdalSammendrag
Tyve isolater som lignet isolater i Fusarium graminearum (Fg) artskomplekset ble isolert fra hvete fra to forskjellige geografiske områder i Etiopia. Multilokus DNA sekvensdata (13 gener: 16.3 kb/ isolat) viste at de etiopiske isolatene tilhørte en ny monophyletisk søstergruppe til F.acaciae-mearnsii innen Fg komplekset. Analyse med MLGT prober viser at det i disse isolatene har skjedd en rekombinasjon mellom isolater med en 15ADON og NIV kjemotype, og dette ble bekreftet med DNA sekvensering. Dette er første gang en slik rekombinasjon innen TRI klusteret er vist. Patogenitetstester viser at denne nye arten kan gi Fusarium Head Blight i hvete og danne 15ADON in planta.
Forfattere
Kerry O\"Donnell Todd J. Ward Dereje Aberra T. Aoki H. Corby Kistler Åsmund Bjørnstad Sonja KlemsdalSammendrag
Tyve isolater som lignet isolater i Fusarium graminearum (Fg) artskomplekset ble isolert fra hvete fra to forskjellige geografiske områder i Etiopia. Multilokus DNA sekvensdata (13 gener: 16.3 kb/ isolat) viste at de etiopiske isolatene tilhørte en ny monophyletisk søstergruppe til F.acaciae-mearnsii innen Fg komplekset. Analyse med MLGT prober viser at det i disse isolatene har skjedd en rekombinasjon mellom isolater med en 15ADON og NIV kjemotype og dette ble bekreftet med DNA sekvensering. Dette er første gang en slik rekombinasjon innen TRI klusteret er vist. Patogenitetstester viser at denne nye arten kan gi Fusarium Head Blight i hvete og danne 15ADON in planta.
Sammendrag
Healthy seed is important for a successful plant production and organic cereal production must rely on management of seed-borne diseases without synthetic seed treatment chemicals. Inoculum thresholds, i.e. the level of seed borne inoculum that can be accepted, are needed for organic cereal production. In general, significantly lower infection frequencies of seed borne diseases are recorded on seedlings than on seed. The aim of the work presented was to compare transmission of Drechslera teres from barley seeds to seedlings in soils with different content of organic materials. Experiments with two seed lots (93 % and 94 % D. teres, respectively) have been carried out in greenhouse with 8 different soils collected in different cereal growing regions. 100 seeds with 3 replicates from each seed lot were planted in each soil type and placed for emergence at 12 oC. Percent emergence and percentage seedlings with symptoms of net blotch were recorded at BBCH 10-12. The net blotch frequency as average for the two seed lots ranged from 11 to 21 % in the different soils. Higher content of organic materials resulted in less infection frequencies. A correlation was found between the amount of organic materials in the soil and % net blotch (r = -0.83, P = 0.009). Experiments will be repeated with less infected seed lots.
Forfattere
Guro BrodalSammendrag
Det er ikke registrert sammendrag
Sammendrag
Increasing levels of Fusarium toxins, particularly deoxynivalenol (DON), T-2 /HT-2 and moniliformin, have been recorded in Norwegian cereals during the last few years. Previously F. avenaceum, F. culmorum, F. poae and F. tricinctum were the most common Fusarium species found on cereals in Norway. However, more recently F. graminearum has occurred more frequently, and the T-2/HT-2 toxin producing species F. langsethiae has also been detected, especially in oats. Investigations were made to clarify if there has been a change in the composition of Fusarium species. We are aiming to establish a three-step screening system in order to identify grain lots with high levels of Fusarium toxins: 1- Identify `high-risk" fields/lots, based on information on cultivation practice and climatic conditions, through the use of a FHB-prediction model. 2- Analyze the `high-risk" lots using a rapid test selected for its capacity to detect Fusarium toxins in a large number of grain samples at low cost. 3- Forward selected samples (based on analyses in step 2) for chemical mycotoxin analyses. Since 2004, we have run chemical mycotoxin analyses on grain samples from oat and spring wheat grown in Norway under different climatic conditions. Prediction models will be developed to estimate the risk of Fusarium infection and mycotoxin development in cereal fields, based on data for weather and cultivation practices. Preliminary results from using the prediction models will be presented.
Forfattere
Sonja Klemsdal Heidi Udnes Aamot Erik Lysøe Jafar Razzaghian Oleif Elen Ingerd Skow Hofgaard Marika Jestoi Guro BrodalSammendrag
I to veksthusforsøk ble hvete og havre sprayinokulert under blomstring med en enkelt eller en blanding av flere Fusarium arter. De artene som ble studert var F. graminearum, F. culmorum, F. avenaceum, F. poae og F. langsethiae. Vi studerte i hvilken grad samspillet mellom artene påvirket etableringen og veksten av Fusarium, og også hvilken effekt dette hadde på mykotoksinproduksjonen.
Sammendrag
We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in spore development, pathogenicity and secondary metabolism. The FgStuA protein is a member of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and stuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity on wheat and colonization of apple slices. The mutant produces no detectable trichothecenes on the wheat cultivar Bobwhite, and
Sammendrag
We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in spore development, pathogenicity and secondary metabolism. The FgStuA protein is a member of the APSES family which regulate morphogenesis and virulence in ascomycetes. FgStuA is closely related to FoStuA in F. oxysporum and stuA in Aspergillus, but unlike FoStuA mutants, the FgStuA mutants were greatly reduced in pathogenicity on wheat and colonization of apple slices. The mutant produces no detectable trichothecenes on the wheat cultivar Bobwhite, and
Sammendrag
Increasing levels of Fusarium toxins, particularly deoxynivalenol (DON), T-2 /HT-2 and moniliformin, have been recorded in Norwegian cereals during the last few years. Previously F. avenaceum, F. culmorum, F. poae and F. tricinctum were the most common Fusarium species found on cereals in Norway. However, more recently F. graminearum has occurred more frequently, and the T-2/HT-2 toxin producing species F. langsethiae has also been detected, especially in oats. Investigations were made to clarify if there has been a change in the composition of Fusarium species. We are aiming to establish a three-step screening system in order to identify grain lots with high levels of Fusarium toxins: 1- Identify `high-risk" fields/lots, based on information on cultivation practice and climatic conditions, through the use of a FHB-prediction model. 2- Analyze the `high-risk" lots using a rapid test selected for its capacity to detect Fusarium toxins in a large number of grain samples at low cost. 3- Forward selected samples (based on analyses in step 2) for chemical mycotoxin analyses. Since 2004, we have run chemical mycotoxin analyses on grain samples from oat and spring wheat grown in Norway under different climatic conditions. Prediction models will be developed to estimate the risk of Fusarium infection and mycotoxin development in cereal fields, based on data for weather and cultivation practices. Preliminary results from using the prediction models will be presented.