Hopp til hovedinnholdet

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.

2023

Til dokument

Sammendrag

Since the mid-2010s, Phytophthora infestans clones that have been dominant in Western Europe from the beginning of the 21st century, for example, EU_13_A2, EU_6_A1 and EU_1_A1, are being replaced by several other emerging clones, including EU_37_A2. The objective of this study was to determine whether the main drivers for the success of EU_37_A2 in Western Europe are associated with decreased fungicide sensitivity, increased virulence and/or aggressiveness. Axenic P. infestans cultures were sampled in the 2016 and 2017 growing seasons from potato crops in France and the United Kingdom. Amongst these, four genotypes were identified: EU_37_A2, EU_13_A2, EU_1_A1 and EU_6_A1. Although a wide range of fluazinam sensitivity was found amongst individual isolates, clonal lines EU_13_A2 and EU_37_A2 showed decreased sensitivity to fluazinam. EU_37_A2 overcame the R5 differential cultivar more often than isolates of EU_1_A1 or EU_6_A1. However, this does not explain the competitive advantage of EU_37_A2 over the virulent EU_13_A2. The fittest genotype, as measured by aggressiveness under controlled conditions, was EU_6_A1, followed by EU_37_A2, EU_13_A2 and then EU_1_A1. EU_37_A2 isolates also showed a shorter latent period than either EU_6_A1 or EU_13_A2, which could favour its long-term persistence. Overall, the data suggest that the emergence of EU_37_A2 in Western Europe was driven by its resistance to a then-major fungicide and shorter generation time. This conclusion is further supported by the fact that EU_37_A2 emergence was slowed by the progressive reduction in the use of fluazinam as a single active ingredient in the years following its initial detection.

Til dokument

Sammendrag

Lingonberry is an evergreen dwarf shrub abundant in the area of Nordic countries and a food traditionally regarded as a staple of Nordic diets. There is however limited commercial harvest of these readily available berries. The objective of this doctoral thesis is to investigate how the composition Norwegian lingonberries vary and is affected by abiotic and biotic growth conditions. The thesis consists of four papers of which three studies were conducted in controlled conditions investigating the effects of ripening, light conditions, and temperature during ripening on the composition of the targeted compounds in lingonberries. The fourth paper of the thesis investigates the variation in composition of wild Norwegian lingonberries and how different environmental factors influence this composition. In lingonberries, in total 29 phenolic compounds, sucrose, glucose and fructose as well as 4 organic acids and 77 volatile organic compounds were detected.. In the controlled studies time of harvest significantly influenced the quality of the lingonberries. Spectral light composition with supplemental blue wavelengths increased the content of anthocyanins, and slightly influenced the ratio of sugars to organic acids. There was only a limited effect of light intensity on the content of anthocyanins in lingonberries. Berries grown at lower temperatures had a higher content of anthocyanins and organic acids, whereas the other phenolic compounds were not significantly influenced. Latitude and temperature had the most significant effect on the content of anthocyanins in lingonberries. While light conditions only slightly influence berry quality, factors such as amount of precipitation during ripening, the density of deciduous trees, and altitude also significantly influenced berry quality. Precipitation influenced the content of organic acids in the field study. The result from this study further strengthens the evidence that lingonberries are a rich source for dietary polyphenols, and that berry quality increases with later harvest times. High quality lingonberries can be found across the country with large variation within local areas. The combination of field experiments and controlled experiments showed that weather conditions during ripening, latitude and density of deciduous trees all influence berry quality.

Til dokument

Sammendrag

Macroalgae, or seaweeds, have potential for use as feed ingredients and are currently unexploited despite their content of vitamins, minerals, and protein. Brown species can accumulate iodine from seawater and there are strict limits set by the European Food Safety Authority and the FDA regarding iodine content in animal feeds. Iodine can cause health problems for consumers if over or under-consumed and its presence in end food products is strictly regulated. The aim of the present experiment was to gain knowledge on intake, distribution, and excretion of iodine in sheep supplemented with Laminaria hyperborea by-product known to contain iodine. Twelve Norwegian White Sheep male lambs, four months of age, were blocked according to initial live weight (average 37.8 kg) and randomly allocated to two diet groups. Animals were fed gras silage and concentrate, without (CTR) and including the alga by-product at a 6% inclusion rate (HYP). The iodine concentrations were 4.1 and 476 mg/kg dry matter in the CTR and HYP concentrate, respectively. After 26 days of adaptation in a barn, animals were placed in metabolism crates for three consecutive days (Period 1) with collection of rumen fluid (via esophagus), grass silage, feces, urine, and blood for iodine content. After 5 weeks in the barn, animals returned to the metabolism crates for a subsequent three consecutive day sampling and iodine analyzes (Period 2). Data were analyzed via ANOVA using a repeated measure mixed model procedure. Dry matter intake (P = 0.001) and live weight (P = 0.001) increased from Period 1 to Period 2. Lambs fed CTR had higher daily growth rate than those fed HYP (P = 0.001). Iodine intake and excretion in feces and urine increased from Period 1 to Period 2 (P < 0.001, P = 0.010, P = 0.007, respectively). Iodine excreted in feces was 37% and 67% for lambs in fed the CTR and HYP diets, respectively. None of the animals showed signs of iodine poisoning during ten the experiment. We found that most of the iodine excreted from lambs fed the HYP diet was in feces.