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.
2009
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No abstract has been registered
Authors
Carl Gunnar Fossdal Nadeem Yaqoob Halvor SolheimAbstract
The root-rot causing fungus Heterobasidion annosum senso lato is the most devastating pathogen of conifers in Europe. This pathogen enter Norway spruce trees trough the roots and colonizes the tree from within, growing as a saprophyte when established within the dead heartwood and acting as a necrotroph when in contact with living host tissue. The genome of this devastating pathogen has now been sequenced in collaboration with JGI and gene annotation is ongoing and genomic work is currently in progress (Stenlid et al. work in progress). We have worked with the host Norway spruce from a molecular perspective for more than ten years. Twenty percent of the trees in Norwegian spruce stands tend to be infected and this pathogen that can colonize ten meters up inside the trunk. The tree have defences against this pathogen and the attack can be fought off by the bark and living wood but not by the hearthwood. The tree has a unique defense against this internal attack by forming a reaction zone; in this case the host defense is directed inwardly by the still living sapwood toward the central colonized wood. We have in the last years studied the host responses to infection in Norway spruce clones at the transcriptional level and found that the speed of recognition and spatial defense signalling appears to be the hallmarks of trees with high degree of resistance. We strive to study both partners in this pathosystem from a molecular perspective, and are using suppressive subtractive hybridization (SSH) followed by Real-Time RT PCR verification to look at differentially expressed genes(Yakovlev et al. 2008). In addition the colonization profiles are followed on extracted gDNA using quantitative Real-Time PCR (Hietala et al. 2009).
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No abstract has been registered
Abstract
The summary of the main findings from the ongoing EU-project STRIVER (2006-2009) will be presented based on experiences from the four case basins: Glomma (Norway), Tagus (Spania and Portugal), Tungabhadra (India) and Sesan (Vietnam and Cambodia) focusing on integrated water resources management.
Abstract
Neozygites floridana is a fungus in the order Entomophthorales that is a natural enemy of several spider mite species including the two-spotted spider mite, Tetranychus urticae. When conditions are right, this fungus may cause epizootics in spider mite populations and kill high numbers of mites. The fungus is therefore promising for biological control of T. urticae in strawberry and can be used in combination with other pest management strategies. Our previous studies have shown that N. floridana is compatible with other biocontrol methods such as predatory mites. Phytoseiulus longipes fed on fungus-infected T. urticae laid equal number of eggs to those fed on healthy prey. This indicates that the fungus does not affect this predatory mite negatively. In a choice experiment (hosts with and without N. floridana), P. longipes fed indiscriminately irrespective of the presence of the fungus. The compatibility of biological control methods with pesticides is of great importance for an integrated pest management system to work well. Some acaricides and fungicides have the potential to affect both beneficial fungi and predatory mites and careful selection of pesticides that are not harmful to these beneficial organisms can promote their biocontrol potential. Our studies have shown that the fungicides captan, mancozeb, tolylfluanid, fenhexamid, cyprodinil + fludioxonil affect N. floridana in a way that may be detrimental to the biocontrol potential of this beneficial fungus in the field. Use of resistant varieties is also important in integrated pest management because pests are known to be more vulnerable to pathogens if they feed on poor or resistant plants and our studies on effects of host plants of spider mites confirms this.
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No abstract has been registered
Authors
Peder Gjerdrum Mauro BernabeiAbstract
No abstract has been registered
Academic – Threshold facilitations of interacting species
Bjørn Økland, Olav Skarpaas, Kyrre Kausrud
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No abstract has been registered