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
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.
Sammendrag
Karnal bunt er en karanteneskadegjører som forårsaker sotsykdom i hveteaks. Sykdommen er ikke etablert i Norge eller andre europeiske land, men finnes i land som vi importerer hvete ifra. Resultater fra et internasjonalt prosjekt viser at soppens sporer kan overleve i minst tre år i jord, inkludert under norske forhold, og at vanlige hvetesorter er mottagelige for sjukdommen.
Forfattere
Berit Nordskog David M. Gadoury May Bente Brurberg Tor Håkon Sivertsen Roy Kennedy Arne HermansenSammendrag
Downy mildews represent some of the most important plant diseases in the production of several field vegetable crops in Norway. Disease outbreaks are difficult to predict since severity of the diseases and the first appearance of the pathogens can differ substantially between seasons. As part of an ongoing project, the initial sources of inoculum for downy mildews of onion (Peronospora destructor), lettuce (Bremia lactucae) and cucumber (Pseudoperonospora cubensis) is investigated to ensure the use of appropriate control measures for these diseases in Norway. Necrotic leaf tissue from infected plants has been examined for the presence of oospores. Oospores have so far been found profusely in lettuce and sparsely in onion, but not in cucumber. Other aspects that are surveyed are the distribution of spores in air. Spore traps are used to identify both the initial appearance of inoculum, and the presence and amount of spores over a field. To determine spore quantities, real-time PCR has been applied to analyze daily spore catch. These results were compared to data from parallel spore traps where hourly numbers of spores are enumerated by use of microscope. An attempt to backtrack an early infection of P. cubensis was made by producing trajectories to show where possible sources of infection may be located in the case of long distance distribution of spores by air. This work will be continued in 2008 and 2009, and the results will be used for better forecasting of downy mildew pathogens in Norway.
Forfattere
Berit Nordskog David M. Gadoury May Bente Brurberg Tor Håkon Sivertsen Roy Kennedy Arne HermansenSammendrag
Bladskimmel utgjør noen av de viktigste plantesjukdommene i norske frilandsgrønnsaker. Sjukdomsutbrudd er vanskelige å forutse siden angrepsgrad og tidspunkt for første funn av patogenene kan variere fra sesong til sesong. Som del av et pågående prosjekt har smittekilder for bladskimmel i løk (Peronospora destructor), salat (Bremia lactucae) og agurk (Pseudoperonospora cubensis) blitt undersøkt for å sikre at riktige tiltak for kontroll gjennomføres. Forekomst av oosporer i blad og fordeling av sporer i luft har vært undersøkt. Dette arbeidet fortsettes i 2008 og 2009, og resultatene skal brukes til utvikling av bedre varsling av bladskimmelpatogener i Norge.
Forfattere
Berit Nordskog David M. Gadoury May Bente Brurberg Tor Håkon Sivertsen Roy Kennedy Arne HermansenSammendrag
Downy mildews represent some of the most important plant diseases in the production of several field vegetable crops in Norway. Disease outbreaks are difficult to predict since severity of the diseases and the first appearance of the pathogens can differ substantially between seasons. As part of an ongoing project, the initial sources of inoculum for downy mildews of onion (Peronospora destructor), lettuce (Bremia lactucae) and cucumber (Pseudoperonospora cubensis) is investigated to ensure the use of appropriate control measures for these diseases in Norway. Necrotic leaf tissue from infected plants has been examined for the presence of oospores. Oospores have so far been found profusely in lettuce and sparsely in onion, but not in cucumber. Other aspects that are surveyed are the distribution of spores in air. Spore traps are used to identify both the initial appearance of inoculum, and the presence and amount of spores over a field. To determine spore quantities, real-time PCR has been applied to analyze daily spore catch. These results were compared to data from parallel spore traps where hourly numbers of spores are enumerated by use of microscope. An attempt to backtrack an early infection of P. cubensis was made by producing trajectories to show where possible sources of infection may be located in the case of long distance distribution of spores by air. This work will be continued in 2008 and 2009, and the results will be used for better forecasting of downy mildew pathogens in Norway.
Sammendrag
Kålbladskimmel, forårsaket av Hyaloperonospora parasitica (Pers.) Constant., er utbredt i alle deler av verden hvor det dyrkes kålplanter. De første symptomene på kålbladskimmel viser seg vanligvis først på blader og blomsterstander, men alle overjordiske deler av planten kan bli infisert. Frøplanter vil lettere dø som resultat av en infeksjon enn eldre planter. Effekten av patogenet på senere vekststadier er generelt ikke så alvorlig, men kan medføre svekket kvalitet eller redusert avling. Kålbladskimmel er vanlig forekommende på en lang rekke kultur-, ugress- og prydplanter innen korsblomstfamilien (Brassicaceae), men det er noe uklart hvor stor vertsspesialiering patogenet har innen de ulike slekter og arter. Bladskimmelinfeksjoner er polysykliske og danner mange generasjoner med ukjønna konidiesporer i løpet av en sesong. I tillegg kan kålbladskimmel danne hvilesporer (oosporer) som bidrar til at patogenet kan overleve lenge i jord. Hvert trinn i livssyklusen, for eksempel sporespiring, infeksjon, latenstid og sporulering påvirkes av klimatiske forhold. En generell tommelfingerregel for kålbladskimmel er at sjukdommen er mest problematisk i felt ved temperaturer mellom 10 og 15 °C og høy luftfuktighet. Sporulering skjer hovedsakelig om natta og sporene slippes om morgenen når tørkende konidioforer vrir seg kraftig og slynger konidier ut i lufta. De første symptomene på kålbladskimmel kan være synlige allerede 3 til 4 døgn etter infeksjon av konidiene. Konidier av H. parasitica spres med vind og vannsprut lokalt i åkeren og mellom felt som ligger i samme dyrkingsområde. Det er også mulig at konidiene kan fraktes over lengre avstander med luftstrømmer i atmosfæren, men det er uklart hvor langt konidier av H. parasitica kan transporteres og fremdeles være spiredyktige. Dersom oosporer dannes kan disse overleve i planterester og i jord og opptre som primær smittekilde. Kålbladskimmel kan overvintre i vinterettårige, toårige eller flerårige korsblomstra vertplanter. Det er imidlertid noe uklart hvor stor betydning slike vertplanter har som smittekilde for grønnsakvekster. Forebyggende bekjempelse av kålbladskimmel innebærer fjerning av planterester, vekstskifte med ikke korsblomstra vekster og ugresskontroll for å begrense smittekilder lokalt. Systemer som varsler om klimaforhold som fremmer sporulering og infeksjon kan være et godt hjelpemiddel til å vurdere faren for utvikling av bladskimmel og finne riktig sprøytetidspunkt.
Sammendrag
Aerial dispersal of inoculum is critical to the spread of many plant diseases; including potato late blight (Phytophthora infestans (Pi)), lettuce downy mildew (Bremia lactucae (Bl)) and cucurbit downy mildew (Pseudoperonospora cubensis (Pc)). In addition to relative humidity and temperature, spore survival during aerial dispersal is affected by solar irradiation (SI), in particular during long-distance transport at higher altitudes. We evaluated the potential survival of spores in air by placing detached spores of Pi, Bl and Pc on filter paper in either direct sun or shade at time intervals from 0.5 to 3 h (Pi and Bl), or up to 42 hours (Pc). Thereafter, the filter papers were placed in moist chambers for 15 min prior to incubation on pea agar (Pi) or water agar (Bl and Pc) for 24 h, before the viable spores were enumerated. Spores were considered viable if they exhibited a germ tube or released zoospores. Preliminary results show that no spores of Pi, Bl and Pc germinated after 1, 3 and 30 h exposure to direct sun, with critical SI doses near 700, 2000 and 8500 Wm-2, respectively. In shade, no Pi spores germinated after 3 h, while spores of Bl and Pc were still viable after 3 and 42 h, respectively. In Norway, the potential for long distance distribution of Pi is restricted, but more likely for Bl and Pc. Further experiments will be conducted to find the maximum survival time for spores of these pathogens under Norwegian climatic conditions.
Sammendrag
Aerial dispersal of inoculum is critical to the spread of many plant diseases; including potato late blight (Phytophthora infestans (Pi)), lettuce downy mildew (Bremia lactucae (Bl)) and cucurbit downy mildew (Pseudoperonospora cubensis (Pc)). In addition to relative humidity and temperature, spore survival during aerial dispersal is affected by solar irradiation (SI), in particular during long-distance transport at higher altitudes. We evaluated the potential survival of spores in air by placing detached spores of Pi, Bl and Pc on filter paper in either direct sun or shade at time intervals from 0.5 to 3 h (Pi and Bl), or up to 42 hours (Pc). Thereafter, the filter papers were placed in moist chambers for 15 min prior to incubation on pea agar (Pi) or water agar (Bl and Pc) for 24 h, before the viable spores were enumerated. Spores were considered viable if they exhibited a germ tube or released zoospores. Preliminary results show that no spores of Pi, Bl and Pc germinated after 1, 3 and 30 h exposure to direct sun, with critical SI doses near 700, 2000 and 8500 Wm-2, respectively. In shade, no Pi spores germinated after 3 h, while spores of Bl and Pc were still viable after 3 and 42 h, respectively. In Norway, the potential for long distance distribution of Pi is restricted, but more likely for Bl and Pc. Further experiments will be conducted to find the maximum survival time for spores of these pathogens under Norwegian climatic conditions.
Populærvitenskapelig – En svamp - to sygdomme
Arne Stensvand, Håvard Eikemo, Bodil Damgaard Petersen
Sammendrag
Artikkelen omhandlar rotstokkrote og lerrote i jordbær som begge er årsaka av Phytophthora cactorum.