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.
2011
Forfattere
Christer MagnussonSammendrag
Nematodes, commonly known as round worms, are the most common multicellular animals on planet Earth. After 1000 million years of evolution members of the phylum Nematoda have a high bionomic diversity. As habitants of the soil and rhizosphere nematodes are involved en energy fluxes, and affect carbon and nutrient cycles. As plant parasites, either alone or in synergism with other pathogens, nematodes are responsible for plant disease complexes and major crop losses. A growth depression in a field of potato (Solanum tuberosum) cv. Saturna [resistant to pathotype Ro1 of potato cyst nematode (PCN) Globodera rostochiensis], suggestive of potato cyst nematode damage, was detected in Grue, eastern Norway. Analyses of soil samples did not detect PCN, but demonstrated the occurrence of a large number of lesion nematodes Pratylenchus penetrans .Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium Streptomyces scabies. Potato yield was reduced by 50% in the affected area of the field. Transect-sampling showed plant growth to be negatively correlated with densities of P. penetrans and suggested a damage threshold of potato to the nematode of 100 specimens per250 g of soil. Common scab (Streptomyces scabies) occurred frequently in the affected area. P. penetrans was present in roots, underground stems, stolons and tubers. Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium. In tubers, nematodes were detected inside cross-lesions typical symptoms of common scab, and occurred also in the outermost 0.5 mm tissue associated with such lesions. In pots with sterile sand, micro-tubers of potato cv. Saturna, produced from meristems, were grown in a green-house infected with, P. penetrans, S. scabies, and a combination of P. penetrans and, S. scabies. P. penetrans alone induced tuber lesions similar to those of common scab. Also, the combined inoculation of the bacterium and the nematode seemed to enhance symptom expression. Similar scab symptoms, in connection with lesion nematode infections, have been observed on potato tubers cv. Oleva, which also is relatively tolerant to common scab. Symptomatic tubers cv. Saturna first stored at 4o C for 20 weeks were transferred to pots with sterile sand and grown for 3 months in the green-house. In these cultures P. penetrans was first detected in soil 8 weeks after planting. Examination at harvest of soil, roots, stolons, tubers demonstrated symptoms typical of P. penetrans. Interestingly, P. penetrans survives storage of potatoes, from which new infections may develop. Hence, potato tubers do appear to be an important means for the spread of P. penetrans to new areas. The fact that the symptoms induced by this nematode may be mistaken for symptoms of common scab suggests that the frequency of S. scabies might have been overestimated in regular surveys. Infections by P. penetrans have important implications for scab control. This pertains in particular to recommended maintenance of high soil moisture at and during 4-9 weeks after tuber set. If symptoms are related to nematode infection rather than to the scab bacterium, this recommendation would allow for a rapid build-up of lesion nematodes resulting in a decrease in both yield and marketability of the tubers. Further studies are needed to investigate the extent of this problem.
Forfattere
Ricardo HolgadoSammendrag
Cyst nematodes, Heterodera spp. are known world-wide as parasites of cereals and grasses. Norwegian surveys have revealed that nematodes belonging to the H. avenae complex occur throughout the country; our studies have combined morphology, protein variability (IEF), bio-tests and internal transcribed spacers (ITS3 and ITS5) for the identification of Heterodera populations. Our results showed some divergences between techniques in species identity of some of the studied populations H. avenae is the most common species followed by H. filipjevi (Holgado et al., 2009).. Several populations of H. filipjevi west did not reproduce in oat differentials. In this case both the morphology and protein patterns rather indicated these populations to belong to H. pratensis. In this study a population from Brekstad differed from all other populations in its morphology, and the protein pattern was close to H. mani. This population was collected from barley, and in the pathotype test it was virulent on several barley cultivars. Mathews, 1971reported that H. mani did not reproduce on cereals while (Cook, 1982) indicates that some barley cultivars can serve as hosts. Surprisingly the ITS studies indicated the Brekstad population to be close to H. avenae. This population is in many ways strikingly different from H. avenae, and this result may indicate a need to revise the present gene library of H. avenae. It also demonstrates the need for using several techniques in species identification. In our study the least degree of divergent results on nematode identity is between morphology and IEF.
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
Cyst nematodes, Heterodera spp. are known world-wide as parasites of cereals and grasses. Norwegian surveys have revealed that nematodes belonging to the H. avenae complex occur throughout the country; our studies have combined morphology, protein variability (IEF), bio-tests and internal transcribed spacers (ITS3 and ITS5) for the identification of Heterodera populations. Our results showed some divergences between techniques in species identity of some of the studied populations H. avenae is the most common species followed by H. filipjevi (Holgado et al., 2009).. Several populations of H. filipjevi west did not reproduce in oat differentials. In this case both the morphology and protein patterns rather indicated these populations to belong to H. pratensis. In this study a population from Brekstad differed from all other populations in its morphology, and the protein pattern was close to H. mani. This population was collected from barley, and in the pathotype test it was virulent on several barley cultivars. Mathews, 1971reported that H. mani did not reproduce on cereals while (Cook, 1982) indicates that some barley cultivars can serve as hosts. Surprisingly the ITS studies indicated the Brekstad population to be close to H. avenae. This population is in many ways strikingly different from H. avenae, and this result may indicate a need to revise the present gene library of H. avenae. It also demonstrates the need for using several techniques in species identification. In our study the least degree of divergent results on nematode identity is between morphology and IEF.
Forfattere
Ricardo HolgadoSammendrag
In 1955 the potato cyst nematode was recorded for the first time in Agder. This detection produced the initial legislation of PCN control, and was implemented based on the statutory regulation of 1916. Since 1956 PCN was given quarantine status in infested agricultural land and home gardens. Official controls of certified seed potatoes started in 1939. Each year about 3000 soil samples are analyzed for PCN to clear areas for certified seed potato production. These areas are so far free of PCN. The total acreage with seed potatoes in 2009 was 813.7 Ha. Extensive surveys started in 1955; and were carried uninterrupted until the end of the 1990ties. These surveys included producing potato agricultural land and home gardens. In 2009 a new national survey program for the principal potato districts has started, the surveys is aimed to update the PCN occurrence. The surveys will continue during the subsequently years until all major potato areas will be cover. Statutory regulations for PCN from 1956-2010 to Support to Norwegian Food Safety Authority The regulations have without doubt contributed in preventing PCN infestations in the seed potato areas, and probably also prevented further spreading of wPCN and virulent yPCN as each the find has been placed under quarantine. Permanent grass as a statutory regulation in home garden plots may have contributed to reduce the spread of wPCN to commercial fields. The regulations have most probably made possible the early reduction in use of chemical fumigants, organophosphates or carbamate nematicides. These chemicals have not been used since the early 1970s. The domestic production of seed potato has been kept free of PCN by frequent inspections and analyses for more than 50 years. The fact that farmers are not allowed to import seed potatoes adds to the level of security. New project Studies on the biology of potato cyst nematodes (Globodera spp.) under Nordic conditions for improving management and regulation in Norway. To increase the scientific basis for amending the management system for PCN, Globodera spp under Nordic conditions.
Forfattere
Ricardo HolgadoSammendrag
In 1955 the potato cyst nematode was recorded for the first time in Agder. This detection produced the initial legislation of PCN control, and was implemented based on the statutory regulation of 1916. Since 1956 PCN was given quarantine status in infested agricultural land and home gardens. Official controls of certified seed potatoes started in 1939. Each year about 3000 soil samples are analyzed for PCN to clear areas for certified seed potato production. These areas are so far free of PCN. The total acreage with seed potatoes in 2009 was 813.7 Ha. Extensive surveys started in 1955; and were carried uninterrupted until the end of the 1990ties. These surveys included producing potato agricultural land and home gardens. In 2009 a new national survey program for the principal potato districts has started, the surveys is aimed to update the PCN occurrence. The surveys will continue during the subsequently years until all major potato areas will be cover. Statutory regulations for PCN from 1956-2010 to Support to Norwegian Food Safety Authority The regulations have without doubt contributed in preventing PCN infestations in the seed potato areas, and probably also prevented further spreading of wPCN and virulent yPCN as each the find has been placed under quarantine. Permanent grass as a statutory regulation in home garden plots may have contributed to reduce the spread of wPCN to commercial fields. The regulations have most probably made possible the early reduction in use of chemical fumigants, organophosphates or carbamate nematicides. These chemicals have not been used since the early 1970s. The domestic production of seed potato has been kept free of PCN by frequent inspections and analyses for more than 50 years. The fact that farmers are not allowed to import seed potatoes adds to the level of security. New project Studies on the biology of potato cyst nematodes (Globodera spp.) under Nordic conditions for improving management and regulation in Norway. Major goal is to increase the scientific basis for amending the management system for PCN, Globodera spp under Nordic conditions.
Forfattere
Ricardo HolgadoSammendrag
mest avanserte og fremgangsrike planteparasitter. PCN ble påvist i Europa av Kühn i 1881, og i 1923 erklærer Wollenweber den som egen art. Stone i 1973 skiller PCN i to arter. Gul PCN (Globodera rostochiensis) og hvit PCN (G. pallida). I Norge ble PCN først påvist 1955 i Agderfylkene. PCN har spredt seg raskt og i1993 ble de første funn gjort i Nord-Trøndelag. På verdensbasis er PCN funnet utbredt i 23 land og har en begrenset forekomst i 42 land, og i tillegg er det 130 land det ikke er blitt påvist enda. Både gul og hvit PCN er klassifisert som karanteneskadegjørere i 106 respektive 55 land. I de siste årene har PCN blitt påvist i Australia, Canada og USA, som på nytt satt fokus på hvor lett PCN kan spres og hvilke nasjonale konsekvenser PCN har. De plantesanitære og økonomiske konsekvensene av PCN er betydende. I EU vil PCN bli regulert i det nye EU direktivet 2007/33/EC som implementeres nå. Formålet med direktivet er å bergrense og kontrollere spredningen til PCN. I direktivet gjøres det ingen forskjell mellom gul og hvit PCN, det nevnes at arealer for settepotet og planter til videre dyrking må ha en offisiell dokumentasjon om PCN status, det skal årlig gjennomføres offisiell prøvetaking av 0,5 % av arealet av felt for produksjon av annen potet enn settepotet. Smittede felt får ikke brukes til produksjon av settepotet eller planter til videre dyrking. Bekjempelsestiltak iverksettes på smittede felt som skal brukes til produksjon av annen potet enn settepotet. Ved resistensbryting skal PCN populasjonen rasetestes. Det skal sendes en årsrapport til EU om tiltak som iverksettes i hvert land. I dag benyttes nematicider for å kontrollere PCN, og samtidig disponeres mye resurser for å foredle sorter med resistens.
Forfattere
Ricardo HolgadoSammendrag
Potetcystenematodene (PCN) Globodera spp. er opprinnelig fra fjelltrakter i Peru og Bolivia. PCN er en av de mest avanserte og fremgangsrike planteparasitter. PCN ble påvist i Europa av Kühn i 1881, og i 1923 erklærer Wollenweber den som egen art. Stone i 1973 skiller PCN i to arter. Gul PCN (Globodera rostochiensis) og hvit PCN (G. pallida). I Norge ble PCN først påvist 1955 i Agderfylkene. PCN har spredt seg raskt og i1993 ble de første funn gjort i Nord-Trøndelag. På verdensbasis er PCN funnet utbredt i 23 land og har en begrenset forekomst i 42 land, og i tillegg er det 130 land det ikke er blitt påvist enda. Både gul og hvit PCN er klassifisert som karanteneskadegjørere i 106 respektive 55 land. I de siste årene har PCN blitt påvist i Australia, Canada og USA, som på nytt satt fokus på hvor lett PCN kan spres og hvilke nasjonale konsekvenser PCN har. De plantesanitære og økonomiske konsekvensene av PCN er betydende. I EU vil PCN bli regulert i det nye EU direktivet 2007/33/EC som implementeres nå. Formålet med direktivet er å begrense og kontrollere spredningen til PCN. I direktivet gjøres det ingen forskjell mellom gul og hvit PCN, det nevnes at arealer for settepotet og planter til videre dyrking må ha en offisiell dokumentasjon om PCN status, det skal årlig gjennomføres offisiell prøvetaking av 0,5 % av arealet av felt for produksjon av annen potet enn settepotet. Smittede felt får ikke brukes til produksjon av settepotet eller planter til videre dyrking. Bekjempelsestiltak iverksettes på smittede felt som skal brukes til produksjon av annen potet enn settepotet. Ved resistensbryting skal PCN populasjonen rase testes. Det skal sendes en årsrapport til EU om tiltak som iverksettes i hvert land. I dag benyttes nematicider for å kontrollere PCN, og samtidig disponeres mye resurser for å foredle sorter med resistens. Potetprodusenter i England bruker ca. Nok. 584 mill. pr år for å sikre sin potetproduksjon. Etter siste oppdagelse av PCN i Australia har mye ressurser blitt benyttet for å utrydde PCN, da det er blitt estimert at det vi koste ca. Nok 216 milliarder i en periode av 20 år hvis PCN blir utbredt i landet. I tillegg til Australia har land som Israel, USA og Canada investert store ressurser for å utrydde PCN, da de mener at på lang sikt er dette billigere enn å leve med PCN. For å gjøre dette mulig har disse land satt i verk strenge restriksjoner. Disse restriksjonene omfatter forbud mot å dyrke potet og andre vertsplanter, benytte store menger nematicider, og prøvetaking. I USA har det 2006-2009 blitt analysert 257 700 prøver, etter påvising av hvit PCN i 9 felt i Idaho. USA har som målsetting å utrydde PCN på 7 år. Som resultat av EU:s direktiv (EC) No 1107/2009 om begrensning av giftige kjemikaler som forårsaker som forårsaker helse- og miljøproblem forventes bruket av de fleste nematicidene å være forbudt i 2015. For å imøtekomme disse utfordringene har forskere i Storbritannia startet sekvensering av hvit PCN. Det er ledet av University of Leeds, i samarbeid med Rothamsted Research, SCRI, og Sangers Institute, og har et budsjett av Nok 15 mill. Det forventes at dette kan gi nye bærekraftige alternativer til bekjempelse av PCN. I tillegg bruker andre Europeiske land ressurser på å finne alternativer for bekjempelse med fangevekster og biofumiganter. I det fleste land omfatter bekjempelse i dag bruk av nematicider, bruk av sertifisert settepotet, og kontrollert bruk av resistente sorter for å unngå oppformering av resistensnedbrytende raser. I tillegg har de et karanteneregelverk. Dette bidrar til en lønnsom potetproduksjon.
Sammendrag
The Norwegian Public Road Adminstration (Statens vegvesen) is planning a new major road (E6) from Ringebu south to Otta in Gudbrandsdalen. A vegetation project for knowledge development concerning restoration and reestablishment of the vegetation were established in 2009, and accomplished by Bioforsk in cooperation with Vegetation adviser Tanaquil Enzensberger. Gudbrandsdalen with the river “Lågen” is a valley in the middle of southern Norway. The area belongs to the slightly continental section of south-boreal vegetation zone (Sb-C1), a phyto-geographical region which is rare in Norway and contains unique biological diversity. As an example we have the fern Diplazium sibiricum that grows in fertile hardwood forest and is classified as vulnerable (VU) on the National red list, the ligneous plant Salix triandra (VU) that grows on the river banks and the vascular plant Stellaria palustris (EN), prefering swamps on the fluvial-areas. In addition there are many threatened vascular plants connected to the cultural landscape, huge rocks with rare lichens and ravines with unique species communities in the forests. Climate, geology and vegetation of the area are described and different methods for conservation proposed. A method for decisions about which plant or plant communities to conserve by moving or propagation is suggested. Erosion, soil management, availability of phosphorus and nitrogen in the topsoil, alien and invasive species as well as restoration of wetlands are discussed. Five different methods for establishing vegetation are proposed. 1: Conventional sowing on cultivated and other disturbed sites. The seed mixture should be of local origin, but for the time being not accessable. 2: Natural revegetation from topsoil in forest areas, with the exception of forest soils high in plant nutrition, which requires special adjustments as mixing the soil with nutrient-poor forest soil or sowing. 3: Spontaneous revegetation without topsoil on one location with calcareous and coarse mineral soil and drought-tolerant vegetation, where the risk for contamination of weeds is low. 4: Donor-receptor method (“hay method”) for conservation of threatened seminatural meadows and creation of refuges for threatened plant species. 5: Vegetation-mat method (“turf roof method”) on one location with natural pasture containing vegetation of special interest. These five methods in combination with conservation of unique plants and plant communities will minimize the environmental impact of the road construction.
Sammendrag
Artikkelen omhandlar sjølvrekrutterande kjøtproduksjon på storfe på Vestlandet og i Agder. Den diskuterer kva verknader vekst i denne næringa kan få for biomasseuttak og attgroing av kulturlandskap og beite i regionen.
Forfattere
Reidun PommerescheSammendrag
Undervisningsaktiviteter for 6. klasser med vekt på å se på og artsbestemme meitemark, samt snakke om bioenergi. Ca 1,5 timer x 2 klasser pr dag. Samarbeid med Kjetil Valde, Ingvar Kvande, Alana Lennon, Hanne Dalen, Gunnhild Gjørsvik.