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.
2016
Forfattere
Riikka Linnakoski Robert Jankowiak Caterina Villari Thomas Kirisits Halvor Solheim Z. Wilhelm de Beer Michael J. WingfieldSammendrag
Two species of blue-stain fungi with similar morphologies, Ophiostoma brunneo-ciliatum and Ophiostoma clavatum, are associates of bark beetles infesting Pinus spp. in Europe. This has raised questions whether they represent distinct taxa. Absence of herbarium specimens and contaminated or mistakenly identified cultures of O. brunneo-ciliatum and O. clavatum have accentuated the uncertainty regarding their correct identification. The aim of this study was to reconsider the identity of European isolates reported as O. brunneo-ciliatum and O. clavatum by applying DNA-based identification methods, and to provide appropriate type specimens for them. Phylogenetic analyses of the ITS, βT, TEF-1α and CAL gene sequences revealed that the investigated isolates represent a complex of seven cryptic species. The study confirmed that ITS data is insufficient to delineate species in some Ophiostoma species clusters. Lectotypes and epitypes were designated for O. clavatum and O. brunneo-ciliatum, and three new species, Ophiostoma brunneolum, Ophiostoma macroclavatum and Ophiostoma pseudocatenulatum, are described in the newly defined O. clavatum-complex. The other two species included in the complex are Ophiostoma ainoae and Ophiostoma tapionis. The results suggest co-evolution of these fungi in association with specific bark beetles. The results also confirm the identity of the fungus associated with the pine bark beetle Ips acuminatus as O. clavatum, while O. brunneo-ciliatum appears to be mainly associated with another pine bark beetle, Ips sexdentatus.
Forfattere
Hugo de Boer Maria Gulbrandsen Asmyhr Hanne Hegre Grundt Kjersti Sjøtun Hans K. Stenøien Jan Ove Gjershaug Kjetil Hindar Lawrence R. Kirkendall Nina Elisabeth Nagy Anders Nielsen Eli Knispel Rueness Odd Terje Sandlund Gaute VelleSammendrag
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The necrotrophic fungus Drechslera teres causes net blotch disease in barley by secreting necrotrophic effectors (NEs) which, in the presence of corresponding host susceptibility factors (SF), act as virulence factors in order to enable host colonization. At present the resistance within most Norwegian cultivars is insufficient. This study aims at detecting QTL associated with resistance and susceptibility in the Nordic barley breeding material and at discovering new NE _ SF interactions. This knowledge together with an understanding of the genetic background of the Norwegian net blotch population will be utilized to speed up resistance breeding. Resistance of a segregating mapping population of a cross between the closely related Norwegian varieties Arve and Lavrans to three Norwegian D. teres isolates was assessed at seedling stage in the greenhouse and in adult plants in the field. QTL mapping revealed four major QTL on chromosomes 4H, 5H, 6H and 7H. The 5H and 6H QTL accounted for up to 47% and 14.1% of the genetic variance, respectively, and were found both in seedlings and adult plants with the latter QTL being an isolate-specific association. The high correlation of seedling and adult resistance (R2=0.49) suggests that components of adult plant resistance can be predicted already at the seedling stage. Selected isolates and their culture filtrates will be screened on selected barley lines to characterize novel NE - SF interactions and to map the corresponding sensitivity loci. Effector protein candidates will be purified and further analysed to verify their effect on disease development. Additionally, 365 Norwegian D. teres isolates and a selection of globally collected isolates are currently being ddRAD genotyped in order to obtain SNP markers to study the genetic diversity and population structure of the current Norwegian fungal population. This data will also allow us to perform Genome Wide Association Studies (GWAS) to identify potential novel NE genes.
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Foredrag – Control of fire blight in Norway 1986-2015
Arild Sletten, Venche Talgø, Trond Rafoss, ...
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Fire blight was detected for the first time in Norway in 1986. It was a limited outbreak on the West Coast, only on ornamentals, particularly on Cotoneaster. An organization for the eradication and containment of fire blight was quickly established, and given comprehensive statutory powers and government resources to do surveys and eradicate diseased plants and highly susceptible plants from contaminated areas. The work has managed to restrict fire blight to the West Coast. Eastern and Northern parts of the country are considered pest free areas. The disease has not moved into important fruit-growing areas. Spread of fire blight to new areas has mainly been due to uncontrolled movement of beehives. From 1969 to 2016 import of all host plants from countries with fire blight has been prohibited. Systematic yearly surveys by foot and car in all parts of the country, using digital maps, internet connected tablets with GPS, and software for registrations made in the field have proved to be an efficient tool to spot new outbreaks at an early stage and start eradication, thus limiting further spread.
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