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
In 1996, a survey on cavity spot started in Norway. Among the Pythium species isolated from the lesions a pathogenic Pythium was found that could not be identified neither by morphological nor by molecular methods (ITS sequencing). This Pythium sp. was repeatedly detected using specific primers developed for this propose and in many cases isolated from cavity spots lesions. The isolates from the new species do not produce zoospores. Oogonia are smooth walled and mostly intercalary with an average size about 20µm. Oospores are aplerotic with an average diameter approximately 17 µm and wall less then 2 µm thick. Antheridia are mostly monoclinous with a sort stalk or sessil, but diclinous antheridia are also common. The modal number of antheridia per oogonium is one or two. Some differences are observed between the isolates studied. Some isolates have a daily growth rate of ca 23 mm on PCA at 25 °C while others have a growth rate around 28 mm. The isolates that grow slower have a tendency to produce one antheridium per oogonium while the isolates with higher growth rates normally produce two. These two groups could also be differentiated based on their ITS sequences which showed 97.8% identity in the 955 base pair rDNA fragment. By using the developed PCR primers it is possible to detect isolates that do not produce the sexual stage in single cultures. These isolates have the same ITS sequence and a similar growth rate and pattern than the fast growing fertile ones.
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.
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
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.
Forfattere
Tove Maria Østensvik Kaj Bo Veiersted Emmanuel Cuchet Petter Nilsen Jan Johansson Hanse Caisa Carlzon Jørgen WinkelSammendrag
The present cross-sectional study was performed to analyze potential risk factors for upper extremity disorders in two groups of forest machine operators driving harvesting vehicles and performing equal tasks in France (n=18) and Norway (n=19). This comparative design implied similar work tasks, but potentially different external work demands. Previous studies have suggested higher levels of neck and shoulder complaints among Norwegian operators compared to those of the French. This may be related to different external work demands and/or individual motor performance. Surface electromyography (EMG) of the right upper trapezius (RUT) and extensor digitorum (RED) muscles were measured continuously during 1 working day (7.5–8 h per operator) and video of body postures was recorded inside the cabin (1 h per operator). A questionnaire on external work demand factors and psychosocial stressors was used together with the collection of symptom data. A physical examination was performed on all workers. Borg's CR-10 scale of intensity of discomfort/pain was rated four times throughout the test day. The French operators reported less complaint (p<0.01) in the right neck compared to their Norwegian colleagues. Furthermore, the French had on average two to three times longer lunch breaks during 5 work days, less continuous hand intensive use of the control lever with more frequent short breaks during the test day compared to the Norwegian operators. However, the average static load level on the RUT muscle for the whole working day was significantly higher among the French (0.7% EMGmax) in comparison with the Norwegian operators (0.3% EMGmax). No difference was found in number of periods with sustained low-level muscle activity neither in the RUT nor the RED muscle. In conclusion, our results support that the higher prevalence of discomfort/pain among the Norwegian forest machine operators may be related to organizational factors.
Sammendrag
The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of modified wood is taken in this study. A specific and quantitative real-time PCR (QRT-PCR) assay was now established for identifying and quantifying early stages of fungal colonisation in modified wood and for profiling growth dynamics of the white-rot fungus Trametes versicolor through different stages of decay. QRT-PCR of colonisation of three different wood modification systems (acetylation, furfurylation, thermal modification), two reference treatments (Cu-HDO, CCA) and Scots pine sapwood as control was performed. Incubation time was 2, 4, 6, 8 and 10 weeks...
Sammendrag
Teger er viktige skadedyr i både integrert og økologisk fruktdyrking. I ei undersøking i 2006 vart parasitteringsgrav av teger undersøkt i 18 fruktfelt i Noreg. Resultata viste at i snitt 30 % av dei vanlegaste artane var parasittert.
Forfattere
Åsmund AsdalSammendrag
Potet er verdens tredje viktigste matplante. Bare hvete og ris dyrkes i større mengder enn potet, men ingen matplante dyrkes i flere land enn poteten. Poteten har et stort uutnyttet potensiale og gir muligheter til å skaffe verdens økende befolkning nok mat og sunn mat i årene som kommer. FN og FAO (Verdensorganisasjonen for mat og landbruk) har proklamert 2008 som Det internasjonale potetåret. The International Year of the Potato (IYP) vil bli markert verden over, og formålet er å fokusere på potetens betydning for ernæring og verdens matvareforsyning.
Forfattere
Johannes DeelstraSammendrag
Foredraget handlet om hvilke problemr vi står overfor når det gjelder det å produsere nok mat. Hvordan skjer vanning, hvilke forskjellige metoder som finnes, hva er vannbehovet, hvilke forbedringer innenfor vanningssystemer, hvilke problemer når knappe vannressurser, vannforurensning, hvordan å fordele vannet innefor landesgrenser men også mellom land