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
Oskar PuschmannSammendrag
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Forfattere
Bjørn Egil FløSammendrag
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Forfattere
Håvard SteinshamnSammendrag
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Sammendrag
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Sammendrag
Microsatellite markers are one of the most valuable genetic marker because of high polymorphism, codominant, high reproducibility and relatively high abundance in the genome. Classical techniques to identify and to develop microsatellite markers are time-consuming and require cloning and library construction followed by Sanger sequencing. In the recent years Next Generation Sequencing (NGS) have been widely used to identify molecular markers for non-model organisms. To test the efficiency of NGS techniques in developing molecular markers, we have used double digest Restriction site Associated DNA Sequencing (ddRADseq) to identify microsatellites in Heracleum. Genomic DNA from three individuals digested with SbfI and NdeI followed by size selection and library construction and then DNA fragments were sequenced with Ion Torrent PGM. After trimming adaptors and evaluating the quality of reads, QDD software was used to screen reads with microsatellite motives containing two, three, four, five and six nucleotide repeats. Almost 2% of all sequences were consisted microsatellites repeats. Fifty four singleton and consensus sequences were bioanformatically confirmed and were checked for contamination and similarity with NCBI nucleotide database. Seventy percent of the sequences were represented by (AT)n, (AT)n, (GA)n and (AC)n motives. Twenty five primer pairs were selected to test for amplification and the results showed that most of the loci produced the expected size on Agarose gel. Our results show the high efficiency of ddRADseq in developing sufficient number of markers in a short time where the budget is also limited. Keywords: Microsatellites, Next Generation Sequencing, ddRADseq, Heracleum
Sammendrag
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Sammendrag
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Sammendrag
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Sammendrag
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.
Forfattere
Hans Estrup Andersen Gitte Blicher-Mathiesen Hans Thodsen Peter Mejlhede Andersen Søren E. Larsen Per Stålnacke Christoph Humborg Carl-Magnus Mörth Erik SmedbergSammendrag
Agricultural management practices are among the major drivers of agricultural nitrogen (N) loss. Legislation and management incentives for measures to mitigate N loss should eventually be carried out at the individual farm level. Consequently, an appropriate scale to simulate N loss from a scientific perspective should be at the farm scale. A data set of more than 4000 agricultural fields with combinations of climate, soils and agricultural management which overall describes the variations found in the Baltic Sea drainage basin was constructed. The soil–vegetation–atmosphere model Daisy (Hansen et al. 2012) was used to simulate N loss from the root zone of all agricultural fields in the data set. From the data set of Daisy simulations, we identified the most important drivers for N loss by multiple regression statistics and developed a statistical N loss model. By applying this model to a basin-wide data set on climate, soils and agricultural management at a 10 × 10 km scale, we were able to calculate root-zone N losses from the entire Baltic Sea drainage basin and identify N loss hot spots in a consistent way and at a level of detail not hitherto seen for this area. Further, the root-zone N loss model was coupled to estimates of nitrogen retention in catchments separated into retention in groundwater and retention in surface waters allowing calculation of the coastal N loading.