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
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
Fusarium head blight (FHB) is a widespread and destructive disease of cereals caused by a number of Fusarium species. Under field conditions a mixture of Fusarium species exists. While FHB in wheat has been well studied, Fusarium infection of oats has not yet been characterized. Little is known about how the presence of a mixture of different Fusarium species in the same sample affects the mycotoxin production. During flowering plants of wheat and oats grown under greenhouse conditions were spray inoculated with single and multiple Fusarium species (F. graminearum, F. culmorum, F. avenaceum, F. poae and F. langsethiae). Chemical toxin analysis of harvested grain showed that the content of mycotoxins in oat were generally lower than in corresponding wheat samples. Neither T-2 nor HT-2 was detected in wheat or oat. Neither was it possible to detect F. langsethiae in the kernels when analysed by real-time TaqMan PCR. All wheat samples inoculated with F. graminearum contained relative high levels of deoxynivalenol. Samples infected with F. culmorum contained nivalenol in addition to deoxynivalenol. Moniliformin was detected at levels below the quantification limit in one third of the samples. The inoculation experiment was repeated with an adjusted inoculation procedure for F. langsethiae and F. poae, resulting in good establishment of all Fusarium species. The amounts of the different Fusarium species and the level of the corresponding mycotoxins were determined. The interactions between the Fusarium species regarding establishment on the fungus on the developing kernels and the production of the mycotoxins, was discussed.
Sammendrag
Fusarium head blight (FHB) is a widespread and destructive disease of cereals caused by a number of Fusarium species. Under field conditions a mixture of Fusarium species exists. While FHB in wheat has been well studied, Fusarium infection of oats has not yet been characterized. Little is known about how the presence of a mixture of different Fusarium species in the same sample affects the mycotoxin production. During flowering plants of wheat and oats grown under greenhouse conditions were spray inoculated with single and multiple Fusarium species (F. graminearum, F. culmorum, F. avenaceum, F. poae and F. langsethiae). Chemical toxin analysis of harvested grain showed that the content of mycotoxins in oat were generally lower than in corresponding wheat samples. Neither T-2 nor HT-2 was detected in wheat or oat. Neither was it possible to detect F. langsethiae in the kernels when analysed by real-time TaqMan PCR. All wheat samples inoculated with F. graminearum contained relative high levels of deoxynivalenol. Samples infected with F. culmorum contained nivalenol in addition to deoxynivalenol. Moniliformin was detected at levels below the quantification limit in one third of the samples. The inoculation experiment was repeated with an adjusted inoculation procedure for F. langsethiae and F. poae, resulting in good establishment of all Fusarium species. The amounts of the different Fusarium species and the level of the corresponding mycotoxins were determined. The interactions between the Fusarium species regarding establishment on the fungus on the developing kernels and the production of the mycotoxins, will be discussed.
Forfattere
Guro BrodalSammendrag
Det er ikke registrert sammendrag
Forfattere
Guro BrodalSammendrag
Det er ikke registrert sammendrag
Sammendrag
In April 2007, orange-red pustules were found in needle scars on defoliated, dead shoots on a nordmann fir (Abies nordmanniana) Christmas tree in Rogaland County in south western Norway. A microscope slide made from the pustules revealed Fusarium-macrospores. On average they were 40.2 µm long and 2.9 µm wide (n=50). No microspores were found. A red coloured culture was obtained by transferring spore mass from a sporodochium to PDA (potato dextrose agar) with a sterile needle. The culture was transferred to SNA (spezieller nährstoffarmer agar) where macrospores developed. The majority of the spores had three septa, most of them were slightly curved, apically bent, basal cells were foot shaped, and spores were long and slender. Six singlespore cultures appeared identical on SNA. Two were chosen for an inoculation test. This test took place on 4 June 2007 in a polyethylene tunnel where the plants were kept during the whole experimental period. Nearly fully grown current year shoots on container grown nordmann fir transplants were inoculated by placing PDA agar plugs with fungal growth at the base of some unwounded needles on each shoot. Twelve transplants were used for each of the two isolates. The plants were covered with polyethylene bags for five days. After the bags were removed, the foliage was kept wet throughout the growing season by 1-3 minutes (depending on temperature) overhead irrigation every third hour. Brown shoots developed during the summer regardless of which singlespore isolate that had been used for inoculation. Samples from brown shoots were collected 20 October. No sporodochia, like we found under field conditions in April, had developed on the inoculated shoots. Neither did they develop after incubation in the laboratory. Only a whitish, fluffy mycelium was seen. CZID (Czapek dox iprodione dichloran agar) was used for reisolation from the dead shoots. From each group of 12 inoculated plants, two and three Fusarium-cultures were obtained, respectively. No symptoms were observed and no Fusarium sp. was isolated from the control plants (exposed to same treatment, but agar plugs with no fungal growth had been used). The Fusarium strain could not be accurately identified to species when the FUSARIUM-ID database v. 1.0 (http://fusarium.cbio.psu.edu) was searched with partial sequence of TEF (translation elongation factor 1-"). The original culture plus the two single spore cultures used for inoculation had identical TEF sequences which were most similar to F. acuminatum (97% identity). One out of six single spore cultures from each of the five reisolates, was sequenced. One of them matched the original culture, but the other four were most similar to F. avenaceum (98% identity). Different from the original culture, the F. av.-like isolates had both macro- and microconidia (0-3 septa, oval spore shape). On PDA, the F. ac.-like culture grew 25 mm in 72 hours (dark and 25°C) and the four F. av.-like cultures grew between 32 to 40 mm. They could not be distinguished by colour. Hyphal coils were found on both species, but were most prominent on the F. ac.-like culture. The fact that sequencing revealed involvement of two Fusarium-species, makes is difficult to draw conclusions about pathogenicity, but since the control plants showed no symptoms, there may be indications that the F. ac.-like fungus killed the inoculated shoots and that the F. av.-like fungus came in as a secondary invader from the environment inside or outside the tunnel. F. acuminatum is reported as a pathogen on conifer seeds and seedlings, but to our knowledge this is the first report of a F. ac.-like fungus causing dieback on a Christmas tree.
Forfattere
Venche TalgøSammendrag
In April 2007, orange-red pustules were found in needle scars on defoliated, dead shoots on a nordmann fir (Abies nordmanniana) Christmas tree in Rogaland County in south western Norway. A microscope slide made from the pustules revealed Fusarium-macrospores.
Sammendrag
Målet med dette prosjektet er å utvikle metoder som kan bidra til å redusere risikoen for Fusarium-toksiner i norsk korn. I samarbeid med næringa pågår aktiviteter på to hovedområder: 1 Kartlegging av klimatiske og agronomiske forhold som påvirker angrep av Fusarium og utvikling av mykotoksiner (grunnlag for varsling), samt fokus på dyrkingsteknikk, inkludert sprøyting, som kan redusere risikoen for Fusarium-angrep/toksin-utvikling. 2 Komme fram til analysemetodikk som raskt og rimelig kan måle innhold av mykotoksiner i kornprøver (hurtigmetode) for å identifisere kornpartier med uakseptabelt høyt toksinnivå og dermed avverge at slike partier brukes til mat og fôr.
Forfattere
Ingerd Skow HofgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Brita ToppeSammendrag
Foredraget gir en oppsummering av de funn som er gjort av karantene-skadegjøreren Fusarium foetens i norsk produksjon av Begonia spp.