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.
2020
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Recent discoveries have highlighted multiple mitotically and meiotically inherited alterations in gene expression that could not be explained solely by changes in the DNA sequence but were acknowledged as epigenetic. The modern view on epigenetics considers it as an integral part of genetics. Epigenetic mechanisms are encoded by genes in the genome and contribute to an essential part of genomic diversity, significantly extending its regulatory abilities. Epigenetic mechanisms involve molecular chromatin alterations through DNA methylation and histone modifications, as well as, complex non-coding RNAs and related enzyme machinery leading to changes in gene expression and resulting in changing phenotypes. In plants, epigenetic mechanisms may occur over their lifetime and across multiple generations, and can contribute substantially to phenotypic plasticity, stress responses, disease resistance, acclimation and adaptation to habitat conditions. In this review, we summarize recent advances with regards to Norway spruce epigenomics. We first consider the large size of the spruce genome that is linked to epigenetic mechanisms and why epigenomics is vitally important for spruce. Then, we discuss the molecular machinery supporting epigenetic mechanisms in Norway spruce and putative gene models involved. We presume substantial extension of gene families of epigenetic regulators and non-coding RNAs, especially in reproductive tissues. Norway spruce was the first species among forest trees in which epigenetic memory and epigenetic mechanisms were studied. The induction of an epigenetic memory during sexual reproduction and somatic embryogenesis has been described in Norway spruce. We discuss the latest results of epigenomic variation and epigenetic memory studies in Norway spruce and define the future perspectives for epigenetic studies. However, there is still a long way to decipher how the epigenetic mechanisms are involved in maintaining the stability of the spruce epigenome, how the epigenome is set to produce the epigenetic memory phenomenon and how these may result in an increased rate of adaptation to a changing environment.
Authors
Iben M. Thomsen Håvard Kauserud Paal Krokene Mogens Nicolaisen Per Hans Micael Wendell Beatrix Alsanius Christer Magnusson Johan A. Stenberg Sandra A .I. Wright Trond RafossAbstract
Key words: VKM, risk assessment, Norwegian Scientific Committee for Food and Environment, Norwegian Environment Agency, mycorrhiza. Mycorrhiza is a beneficial association between plant roots and fungi. This mutualistic symbiosis is essential for plant growth in most natural terrestrial ecosystems and in agriculture. Commercial mycorrhizal products containing fungi and bacteria may promote plant growth, especially on sites without a natural microbial community. Due to the risk of unintended negative effects, introduction of new species or genetically different isolates of native species should always be considered carefully. This report assesses the risk of establishment and spread of six fungal species and six bacterial species included in different commercial mycorrhizal products, as well as the species’ potential impact on Norwegian biodiversity. Most of the evaluated fungi and bacteria are probably present in Norway, even though presence at present data only exist for two of the six fungal species. Establishment of the assessed fungi on the plants and sites where they are applied is considered moderately likely, with medium uncertainty, while establishment of the bacterial species is considered to range from very unlikely to very likely depending on the bacterial group, with low uncertainty. The probability of spread to the wider environment ranges from unlikely (four fungal species), to moderately likely (two fungal species), to very likely (five of the six bacterial species). However, for all species it is considered unlikely that establishment and spread would have negative effects on other native species, habitats and ecosystems in Norway.
Authors
Sjur Sandgrind Lihua Han Sarah Usher Kirsty Hassal Olga Sayanova Louise Michealson Richard Haslam Johnathan NapierAbstract
No abstract has been registered
Authors
Rosemary Collier Dominique Mazzi Annette Folkedal Schjøll Quentin Schorpp Gunda Thöming Tor J. Johansen Richard Meadow Nicolai Vitt Meyling Anne-Marie Cortesero Ute Vogler Michael T. Gaffney Martin HommesAbstract
Several important vegetable crops grown outdoors in temperate climates in Europe can be damaged by the root-feeding larvae of Diptera (Delia radicum, Delia floralis, Chamaepsila rosae, Delia platura, Delia florilega, Delia antiqua). Knowledge of pest insect phenology is a key component of any Integrated Pest Management (IPM) strategy, and this review considers the methods used to monitor and forecast the occurrence of root-feeding flies as a basis for decision-making by growers and the ways that such information can be applied. It has highlighted some current management approaches where such information is very useful for decision support, for example, the management of C. rosae with insecticidal sprays and the management of all of these pests using crop covers. There are other approaches, particularly those that need to be applied at sowing or transplanting, where knowledge of pest phenology and abundance is less necessary. Going forward, it is likely that the number of insecticidal control options available to European vegetable growers will diminish and they will need to move from a strategy which often involves using a single ‘silver bullet’ to a combination of approaches/tools with partial effects (applied within an IPM framework). For the less-effective, combined methods, accurate information about pest phenology and abundance and reliable decision support are likely to be extremely important.
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Jukka Salonen Lars Olav Brandsæter Bärbel Gerowitt Jesper Rasmussen M-H. Robin Kirsten Tørresen Muriel Valantin-MorisonAbstract
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Authors
Han Zhang Sabine Andert Lars Olav Brandsæter Jesper Rasmussen M-H. Robin Jukka Salonen Kirsten Tørresen Muriel Valantin-Morison Bärbel GerowittAbstract
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There is a need both in organic farming and on farms using integrated pest management for non-chemical measures that control the perennial weed flora. The effect of mechanical weeding and fertilisation on perennial weeds, fungal diseases and soil structure were evaluated in two different experiments in spring cereals. Experiment I included six strategies. The first strategy was (1) without specific measures against perennial weeds. The other strategies encompassed one or two seasonal control measures; (2) rhizome/root cutting with minimal soil disturbance in autumn, (3) hoeing with 24 cm row spacing, (4) combined hoeing and disc harrowing in autumn, (5) ‘KvikUp’ harrowing in spring, and (6) ‘KvikUp’ harrowing in spring and autumn. Experiment II included factor (i) inter-row hoeing and (ii) fertilisation level. This experiment included the comparison between normal row spacing (12 cm) with weed harrowing versus double row spacing (=24 cm) in combination with inter-row hoeing and 4 fertilisation levels (50–200 kg N ha−1). In experiment I the strategies consisting of no or one direct weed control measure (1, 2, 3 and 5) clearly did not control the perennial weeds. The two seasonal control measures (4 and 6) gave a satisfactory weed control and highest crop yield. The combination of best weed control and no measured harmful effects on soil structure or increase of fungal diseases may explain the highest yields for these strategies. In Experiment II, hoeing and 24 cm spacing gave less perennial biomass compared to 12 cm spacing. Grain yields increased linearly with increasing nitrogen input. The study shows that both inter-row hoeing and weed harrows, are important elements in integrated pest management practice and organic farming. In addition, our results indicate that efficient mechanical weeding is possible without harmful effects in crop rotation consisting of various spring cereals as regards soil structure and plant health.