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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2018

Abstract

Free-living plant-parasitic nematodes (PPN), including migratory endoparasites such as Pratylenchus spp., cause yield reduction in agriculture and horticulture world-wide. In Norway, nematicides are banned due to their adverse effect on human health and the environment. Thus, management of plant-parasitic nematodes rely on cultural practices, such as crop rotation. Free-living PPN tend to have broad host-ranges, which complicates the design of effective crop rotations. Information on the reproductive rate and damage potential of nematode species on different crops is of crucial importance when designing a successful crop rotation. Results from several experiments indicate that in order to reduce the numbers of free-living PPN, the sequence of crops is more important than the length of the rotation. The crop rotation should aim at protecting the most economically valuable crop. An oat (Avena sativa) field in Norway was heavily infested with Tylenchorhynchus dubius (1200 ind/250 ml soil) and a low population of Pratylenchus crenatus (10 ind/250 ml soil). The primary goal was to reduce T. dubius by growing turnip rape (Brassica rapa ssp. oleifera), with carrot as the following crop. T. dubius was reduced with 77-85% after turnip rape. In contrast, the population of P. crenatus increased by more than tenfold. The increased numbers of P. crenatus could be damaging to the carrot crop. This illustrates that crop rotation should be a long-term strategy, with carefully designed rotations to protect the most economically valuable crop (e.g. carrot). This also illustrates the challenges of designing a crop rotation that effectively reduces multiple nematode populations. In a started project, we will use photography with Unmanned Aerial Vehicles and transects to monitor nematode populations and damage in several fields throughout the growing season, and over several seasons. These fields will serve as naturally occurring experiments. We want to develop decision-making tools for nematode management in Norway.

To document

Abstract

Accelerating international trade and climate change make pathogen spread an increasing concern. Hymenoscyphus fraxineus, the causal agent of ash dieback, is a fungal pathogen that has been moving across continents and hosts from Asian to European ash. Most European common ash trees (Fraxinus excelsior) are highly susceptible to H.fraxineus, although a minority (~5%) have partial resistance to dieback. Here, we assemble and annotate a H.fraxineus draft genome, which approaches chromosome scale. Pathogen genetic diversity across Europe and in Japan, reveals a strong bottleneck in Europe, though a signal of adaptive diversity remains in key host interaction genes. We find that the European population was founded by two divergent haploid individuals. Divergence between these haplotypes represents the ancestral polymorphism within a large source population. Subsequent introduction from this source would greatly increase adaptive potential of the pathogen. Thus, further introgression of H.fraxineus into Europe represents a potential threat and Europe-wide biological security measures are needed to manage this disease.

Abstract

Total forfattarliste: Franić, I., Prospero, S., Adamson, K., Allan, A., Auger-Rozenberg, A-M, Augustin, S., Avtzis, D., Barta, M., Boroń, P., Bragança, H., Brestovanská, T., Brurberg, M. B., Burgess, B., Burokienė, D., Černý, K., Cleary, M., Corley, J., Coyle, D. R., Csóka, G., Davydenko, K., Elsafy, M. A. O., Eötvös, C., de Groot, M., Diez, J. J., Lehtijärvi, H. T. D., Drenkhan, R., Fan, J., Grabowski, M., Grad, B., Havrdova, L., Hrabetova, M., Iede, E. T., Kacprzyk, M., Kenis, M., Kirichenko25,45, N., Lacković26,N., Lazarević, J., Leskiv, M., Li, H., Madsen, C.L., Matošević, D., Matsiakh, I., Meffert, J., Migliorini, D., Mikó, Á., Nikolov, C., O'Hanlon, R., Oskay, F., Paap, T., Parpan, T., Petrakis, P.V., Piškur, B., Ravn, H.P., Ronse, A., Roques, A., Schühli, G.S., Sivickis, K., Talgø, V., Tomoshevich, M., Uimari, A., Ulyshen, M., Vettraino, A.M., Villari, C., Wang, Y., Witzell, J., Zlatković, M., Eschen, R.

Abstract

Total forfattarliste: Franić, I., Prospero, S., Adamson, K., Allan, A., Auger-Rozenberg, A-M, Augustin, S., Avtzis, D., Barta, M., Boroń, P., Bragança, H., Brestovanská, T., Brurberg, M. B., Burgess, B., Burokienė, D., Černý, K., Cleary, M., Corley, J., Coyle, D. R., Csóka, G., Davydenko, K., Elsafy, M. A. O., Eötvös, C., de Groot, M., Diez, J. J., Lehtijärvi, H. T. D., Drenkhan, R., Fan, J., Grabowski, M., Grad, B., Havrdova, L., Hrabetova, M., Iede, E. T., Kacprzyk, M., Kenis, M., Kirichenko25,45, N., Lacković26,N., Lazarević, J., Leskiv, M., Li, H., Madsen, C.L., Matošević, D., Matsiakh, I., Meffert, J., Migliorini, D., Mikó, Á., Nikolov, C., O'Hanlon, R., Oskay, F., Paap, T., Parpan, T., Petrakis, P.V., Piškur, B., Ravn, H.P., Ronse, A., Roques, A., Schühli, G.S., Sivickis, K., Talgø, V., Tomoshevich, M., Uimari, A., Ulyshen, M., Vettraino, A.M., Villari, C., Wang, Y., Witzell, J., Zlatković, M., Eschen, R.

To document

Abstract

Acetophenones are phenolic metabolites of plant species. A metabolic route for the biosynthesis and release of 2 defence‐related hydroxyacetophenones in white spruce (Picea glauca) was recently proposed to involve 3 phases: (a) biosynthesis of the acetophenone aglycons catalysed by a currently unknown set of enzymes, (b) formation and accumulation of the corresponding glycosides catalysed by a glucosyltransferase, and (c) release of the aglycons catalysed by a glucosylhydrolase (PgβGLU‐1). We tested if this biosynthetic model is conserved across Pinaceae and land plant species. We assayed and surveyed the literature and sequence databases for possible patterns of the presence of the acetophenone aglycons piceol and pungenol and their glucosides, as well as sequences and expression of Pgβglu‐1 orthologues. In the Pinaceae, the 3 phases of the biosynthetic model are present and differences in expression of Pgβglu‐1 gene orthologues explain some of the interspecific variation in hydroxyacetophenones. The phylogenetic signal in the metabolite phenotypes was low across species of 6 plant divisions. Putative orthologues of PgβGLU‐1 do not form a monophyletic group in species producing hydroxyacetophenones. The biosynthetic model for acetophenones appears to be conserved across Pinaceae, whereas convergent evolution has led to the production of acetophenone glucosides across land plants.