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.
2010
Sammendrag
The leaf blotch complex is one of the most important yield limiting disease on wheat in Norway. It is caused by three pathogens, Septoria tritici ( Mycosphaerella graminicola), Stagonospora nodorum ( Phaeosphaeria nodorum), and Drechslera tritici-repentis (Pyrenophora tritici-repentis). The symptoms of each of the pathogens are similar and easily confused with leaf senescence, making it difficult to assess the true disease severity and thus hampering breeding for leaf blotch resistance. To reduce unnecessary pesticide use and the risk of pesticide resistance developing in the fungal populations, timing of disease control measures are based on forecasting models. The degree of a leaf blotch epidemic is determined by initial inoculums, precipitation, temperature, time, availability of susceptible hosts and the degree of susceptibility. During the last 20 years, the start of the growing season as marked by a soil temperature of 5C, has advanced by 1-1.5 days per year (Rafoss, 2009), indicating an increase in the length of growing seasons. The trend for warmer and wetter growing seasons is predicted to continue in the future. It is of high relevance to the wheat industry to understand the impact of these changes on leaf blotch diseases in the field to optimize disease forecasting and management. We have collected data on leaf blotch severity in the field and weather conditions at different wheat growing areas in Norway over the last 10 years. Based on this data, we do not see a general increase in disease severity over the last decade. However, the data shows that there are local shifts in maximum disease severity; areas that support high disease severity and areas that support very little. Given the amount of initial inoculum and availability of susceptible hosts are comparable between the different wheat growing areas, the local climate per site becomes the determining factor for the epidemic. We studied the effect of relatively small, local differences in precipitation, temperature, and start of growing season on leaf blotch development in the field. The analysis of local shifts in climatic conditions and their relation to disease development allows us to estimate the effect of the changing climate on leaf blotch disease in the future.
Forfattere
Kristin Kaspersen Therese With Berge Steve Goldberg Jan Netland Øyvind Overskeid Trygve StølanSammendrag
Det er ikke registrert sammendrag
Forfattere
Therese With Berge Steve Goldberg Daniel Løvås Jan Netland Øyvind OverskeidSammendrag
Det er ikke registrert sammendrag
Forfattere
Anette SundbyeSammendrag
Det er mange plantevernmidler som er godkjent mot skadedyr, men ikke alle er tillatt brukt i grøntanlegg. Dessuten kan dette endres fra år til år. Kjemiske og mikrobiologiske preparater blir godkjent for en periode på maksimalt 5 år, mens biologiske preparater med makroorganismer (nytteorganismer) blir godkjent for 10 års perioder, før de må revurderes. Dette kunnskapsbladet fra FAGUS gir en oversikt over hvilke plantevernmidler som er tillatt brukt i norske grøntanlegg per august 2010.
Sammendrag
Rapporten gir en fremstilling av biologiske og vannkjemiske data innsamlet i 2009 i vassdragene Leira og Nitelva på Romerike. Dataene utgjør andre året av en treårig overvåkning, igangsatt i henhold til avtale med Interkommunal Innkjøpsordning Nedre Romerike (IINR). Dataene er vurdert i forhold til tilstandskriterier gitt i EUs Rammedirektiv for vann (Vanndirektivet). Data for flere andre mindre vassdrag i regionen er også presentert. 30 stasjoner er gitt en foreløpig klassifisering av økologisk tilstand etter både biologiske og kjemiske støtteparametre, ytterligere 26 er gitt en foreløpig klassifisering etter kjemiske støtteparametre, og 3 stasjoner er gitt en foreløpig klassifisering kun etter biologiske parametere. Årets data indikerer at bare de øverste stasjonene i Leira og Nitelva befinner seg over grensen mellom god/moderat økologisk tilstand. De nedre delene av vassdragene er utsatt for eutrofiering. Metodiske vanskeligheter med klassifisering av leirvassdrag drøftes.
Forfattere
Jens Rohloff Per Winge Jahn Davik May Bente Brurberg K Mockaitis V Shulaev SK Randall Atle Bones Muath AlsheikhSammendrag
In order to support functional genomics research in octoploid (Fragaria x ananassa Duch.) and diploid (F. vesca) strawberry, a customized Fragaria microarray chip was developed as a joint collaboration between Graminor Breeding Ltd. and NTNU. F. vesca cDNA sequences were provided by The Center for Genomics and Bioinformatics, Indiana University (an assembly of >3 million reads from GS-FLX Titanium - Roche/454 Life Sciences sequencing), and about 59,000 publicly available Fragaria EST sequences were uploaded from NCBI. In addition, ~190 Mb of preliminary draft genome sequences from F. vesca were provided by the Strawberry Genome Sequencing Consortium (courtesy to V. Shulaev). cDNAs used as templates for probe design were validated by BlastN against the F. vesca draft genome excluding cDNAs of microbial origin. Genes not represented in the cDNA collection were identified by screening F. vesca draft genome against protein sequences from Arabidopsis thaliana, Vitis vinifera, Ricinus communis and Populus trichocarpa. Exon sequences from genes not found in the cDNAs were included. In total, 43723 unique 60-mer probes were designed and the Agilent eARRAY tool was used to produce a 4x44k format microarray chip. Fragaria chip applicability and feasibility for transcriptional profiling was investigated using either abiotic (low temperature) or biotic (pathogenic fungi) stress treatment. Microarray data will be subsequently integrated with other omics data to address gene-regulatory networks and biological functions. Cold acclimation experiments were focused on short- and long-term effects in meristematic tissue, and revealed the up-regulation of ~100 cold-responsive genes (transcription factors, dehydrins, enzymes), and transcripts involved in starch breakdown and raffinose biosynthesis. Beside central metabolism, secondary metabolism was also strongly modulated as seen by changes in the expression of flavonoid biosynthesis-related genes. Time-course studies of transcriptional responses in F. vesca accessions showing contrasting resistance toward the pathogen Phytophthora cactorum are in progress, and will be presented in-depth.
Forfattere
Liv Ostrem Arild LarsenSammendrag
Neutral detergent fiber, NDF, and the indigestible part, iNDF, were observed from market cultivars of Festulolium (Hykor, Felopa), Norwegian Festulolium candivars, the parent species perennial ryegrass (Lolium perenne) (cv. Napoleon, 4x), meadow fescue (Festuca pratensis) (cv. Fure) and timothy (Phleum pratense) (cv. Grindstad). Additionally leaf:stem ratio, developmental stage (msc) and total dry matter yield were observed. Field trials for dry matter yield assessment were established in 2006 at Vågønes (67°17"N, 14°27"E), Fureneset (61°34"N, 5°21"E), and Bjørke (60°48"N, 11°12"E) and for forage quality assessment at the two first mentioned locations. Genetic variation was identified for NDF and iNDF at early heading and heading stages between the investigated material. Highest content was found in cv. Hykor whereas in candivars only minor content was observed in leaves, however with higher content in stems. Promising candivars (FuRs0463, FuRs0357) from the Norwegian Festulolium breeding programme revealed better or equal to cultivars of their parental species as to content of NDF and iNDF. Winter survival which is a prerequisite for approved cultivars in Norway, was at an acceptable level in the candivars, and further breeding should preferably continue at the amphitetraploid level of the combination between perennial ryegrass and meadow fescue.
Forfattere
May Bente BrurbergSammendrag
Phytophthora cactorum causes crown rot in strawberry (Fragaria x ananassa Dutch.), which is characterized by wilting and eventually collapse of the plant. An efficient control measure is the use of resistant cultivars, however most commercial cultivars are susceptible to the disease. The aim of our work is to generate basic knowledge about P. cactorum resistance as well as to develop genetic markers that can be used as tools for development of resistant cultivars. The genetic complexity of the octoploid cultivated strawberry, has led to development of the diploid wild strawberry (F. vesca) as a model system for Fragaria. We have identified suitable parents after screening accessions of diploid Fragaria sp. for resistance [1], and generated a mapping population which we are currently characterizing. In order to study the plant-pathogen interaction in detail we have identified and characterized resistance genes from diploid strawberry and effector genes from P. cactorum using different transcriptional analysis techniques; nucleotide-binding site (NBS)-profiling for resistance genes, and suppression subtractive hybridization (SSH) as well as a designed effector-specific differential display (ESDD) for genes involved in pathogenicity. This work is supported by The Research Council of Norway. [1] Eikemo H, Brurberg MB, Davik J (2010). Resistance to Phytophthora cactorum in diploid Fragaria species. HortScience. 45:193-197.
Forfattere
May Bente Brurberg Xiaoren Chen May Bente Brurberg Sonja KlemsdalSammendrag
The oomycete Phytophthora cactorum causes crown rot in strawberry, resulting in big economic losses. To unravel the molecular mechanisms that are involved in the pathogenicity of P. cactorum on strawberry, two strategies were followed, SSH cDNA library and effector specific differential display (ESDD). Two cDNA libraries were made, enriched for P.cactorum genes upregulated during infection of strawberry or in in vitro germinating cysts (a developmental stage essential for infection). Recent characterization of oomycete AVR/effector genes revealed that they encode proteins with conserved RxLR-dEER motifs required for translocating these effectors into host cells. The presence of such a conserved "tag" has provided a tool for discovering the otherwise structurally diverse effector genes. To select RxLR effector genes from P. cactorum, ESDD was performed on seven cDNA populations including four developmental stages (mycelium, sporangia, zoospores,germinating cysts) as well as three time points during infection (3, 5, 7 days postinoculation),using RxLR and EER primers. Using these strategies more than 230 gene fragments were isolated. Nearly 30 % of the genes could not be assigned a coding function, using sequence similarity-based function prediction, because either no similar sequences were detected or similarities were found only to putative proteins with unknown function (mostly oomycete). However, several genes potentially relevant for pathogenicity, including several putative RxLR effector and elicitor genes were discovered. The expression of 27 of these genes was studied in detail using real-time RT- PCR, and their upregulated expression during infection relative to dispersal propagules (sporangia) were confirmed for all but one.
Sammendrag
Sturite et al. (2007) investigated growth and death of the major parts of white clover (Trifolium repens L. cv. "Snowy") plants in pure stand and in mixture with meadow fescue (Festuca pratensis L. cv. "Fure") in a combined plot and root window experiment in Norway (60°42"N, 10º51"E). Leaves, stolons and roots were tagged and their lifespan was monitored in harvested and non-harvested stands during two experimental years. The longevity of leaves and petioles ranged from 21 to 86 d (mean = 59 d). About 60% of the leaves produced during the growing season turned over before the autumn. Of the remaining leaves, 70-80 % were dead or had disappeared by the subsequent spring. The lifespan of sections of the main stolons ranged from 111 to over 677 d (mean = 411 d). In particular, stolon sections close to the parent fragment of undisturbed plants were long lived, while sections towards the terminal bud overwintered more poorly and had a much shorter lifespan. The longevity of roots was from 27 to 621 d (mean = 290 d) and was higher for roots appearing in spring and autumn than in summer. Harvesting significantly reduced the longevity of stolons and caused an increased fragmentation of the white clover plant but did not decrease leaf/petiole or root lifespan.