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
Maria Herrero Arthur de Cock Sonja Klemsdal Brita ToppeSammendrag
In 2006, a survey of root diseases in greenhouse pot plants started in Norway. During this survey an unknown Phytophthora sp. was isolated several times. The ITSrDNA region of these isolates were sequenced and compared to the GenBank database. The determined ITS sequences of the isolates matched the sequence of Phythophthora taxon niederhauserii.The diseased plants originated from 5 different greenhouse sites. Isolates were obtained from ivy (Hedera helix), begonia-hybrids (Begonia × hiemalis and Begonais × cheimantha), gloxinia (Sinninga speciosa) and kalanchoë (Kalanchoë blossfeldiana). Symptoms on begonia, gloxinia and ivy included necrotic roots and stems with the necrosis advancing to the leaves via the petioles. In the case of ivy and gloxinia, wilting of the whole plant was observed. In kalanchoë only discoloration of roots and reduced plant growth was seen. Koch postulates have been completed for ivy and gloxinia. The pathogen caused aggressive root-rot in 22 different ivy-cultivars.
Sammendrag
Pythium angriper rotter og rothals i agruk. I en kartlegging gjennomført i "pythium-prosjektet" ble Pythium pahanidermatum funnet i ulike dyrkingsmedier som perilte og torv. det synes også å være gurnn til å betrakte gjenstander(støttepinner, dryppvanningspinner etc) som over tid har vært i direkte kontakt med infiserte media, som infiserte. patogenet er i noen tifeller også funnet i returvann og i jordgulv. i et forsøk hvor smittet materiale ble plassert ute, er det demonstrert at patogenet kan overleve norske vinterforhold. Damping er forsøk som desinfeksjon og det fungerte tilfredstillende.
Sammendrag
Pythium aphanidermatum er en pseudosopp som angriper røtter og rothals hos agurk. I en kartlegging gjennomført i forbindelse med "Pythium-prosjektet" ble P.aphanidermatum funnet i ulike dyrkingsmedier som perlite og torv. Det synes også å være grunn til å betrakte gjenstander (støttepinner, dryppvanningspinner etc) som over tid har vært i direkte kontakt med infiserte media som infiserte. Patogenet er i noen tilfeller også funnet i returvann og i jordgulv. Det er ikke enkelt å påvise P.aphanidermatum utendørs. I et forsøk hvor smittet materiale ble plassert ute, er det demonstrert at patogenet kan overleve norske vinterforhold. Damping er forsøkt for desinfeksjon, og fungerte tilfredsstillende.
Forfattere
Arne Hermansen May Bente Brurberg Vinh Hong Le Abdelhameed Elameen Ragnhild Nærstad Björn Andersson Asko Hannukkala Ari Lehtinen Bent Nielsen Jens G. Hansen Jonathan YuenSammendrag
Variability of the Nordic Phytophthora infestans population
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.
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.
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.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Arne Stensvand Heidi Udnes Aamot Gunn Mari Strømeng Venche Talgø Abdelhameed Elameen Jorunn Børve Sonja KlemsdalSammendrag
The ascigerous stage (formation of perithecia with viable ascospores) of Colletotrichum acutatum was recently reported to occur on fruits of highbush blueberry (Vaccinium corymbosum) in Norway. When 113 isolates of C. acutatum from various plant species were cultured on strawberry leaf agar, nine developed perithecia with viable ascospores. Four isolates originated from apple (Malus domestica) and one each from sweet cherry (Prunus avium), raspberry (Rubus idaeus), highbush blueberry (Vaccinium corymbosum), hollyberry cotoneaster (Cotoneaster bullatus), and northern dock (Rumex longifolius). Except from blueberry, we never detected the ascigerous stage on decaying fruits or any other parts of the above mentioned plant species. On potato dextrose agar, colour of the underside of the cultures forming perithecia varied from light grey-green to dark grey-green or dark brown-green. Colour of the upperside varied greatly, being dark grey-green, grey-brown, grey, and beige-pink, and only two of the isolates were beige-pink (the raspberry and blueberry isolates). Amplified fragment length polymorphism (AFLP) analysis of the isolates using six primer combinations resulted in 103 clear polymorphic bands. A dendrogram was constructed, and based on cluster analysis using genetic similarity, the isolates could be divided into several clusters. Eight of nine perithecia-forming isolates grouped together in the dendrogram, indicating genetical difference from other isolates. This was also supported by Principal Coordinate (PCO) analysis.