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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.

2023

Abstract

The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in Norway. Nursery trials were performed with the families from these crosses and families from seeds collected from open pollination. Traits measured and analysed are seed weight, germination rate, germination percentage, terminal bud set, and seedling heights the first and second years. The seedlings from the population at origin 500 m had lower seed weight, lower heights and earlier bud set than those from the two populations from lower altitude. A considerable variation was present among families within each diallel, and the GCA variance components had the highest values and were significant for most traits. Variance components for SCA and maternal effects were also significant for some traits, but with inconsistent values in the three diallels. A strong relationship was present between the weight of the seed lots from the maternal parent and mean family height after one and two growing seasons. The highest estimate of heritability was observed for bud set, with similar values in all three diallels.

Abstract

The complete diallel cross is the only mating design that provides estimates of variance components of general combining (GCA), specific combining ability (SCA), maternal and reciprocal effects, in addition to heritabilities and genetic correlations. To obtain such estimates, complete diallels were made among 10 trees in each of three natural Norway spruce populations from altitude 300 and 500 m in southern Norway. Seedlings from families from the diallels and open pollinations were tested in short-term tests on agricultural soil at one site at altitude 85 m until age 10 years from seed. Tree height at ages 7 and 10 years and diameter at age 10 had strongly significant GCA variance components within each population. The components for SCA and maternal effects were small and not significant, indicating low levels of non-additive genetic variation. For the days of initiation and cessation of the shoot elongation period the GCA components were dominating and had the highest heritability estimates in two of the diallels. Estimates of genetic correlations between traits measured in earlier nursery trials and height and diameter in the short-term trials had low and not consistent values in the three diallels. The duration of the shoot growth period and rate of growth showed positive relationships with height and diameter. Strong relationships were present between half-sib family means from the diallels and open-pollinated families for height, diameter and phenology traits. Progeny trials testing open-pollinated half-sib families from natural populations can be used for selection of candidates for the initial breeding populations.

To document

Abstract

Increasing levels of dissolved organic matter (DOM) in watercourses in the northern hemisphere are mainly due to reduced acid rain, climate change, and changes in agricultural practices. However, their impacts vary in time and space. To predict how DOM responds to changes in environmental pressures, we need to differentiate between allochthonous and autochthonous sources as well as identify anthropogenic DOM. In this study we distinguish between allochthonous, autochthonous, and anthropogenic sources of DOM in a diverse watercourse network by assessing effects of land cover on water quality and using DOM characterization tools. The main sources of DOM at the studied site are forests discharging allochthonous humic DOM, autochthonous fulvic DOM, and runoff from urban sites and fish farms with high levels of anthropogenic DOM rich in protein‐like material. Specific UV absorbency (sUVa) distinguishes allochthonous DOM from autochthonous and anthropogenic DOM. Anthropogenic DOM differs from autochthonous fulvic DOM by containing elevated levels of protein‐like material. DOM from fishponds is distinguished from autochthonous and sewage DOM by having high sUVa. DOM characteristics are thus valuable tools for deconvoluting the various sources of DOM, enabling water resource managers to identify anthropogenic sources of DOM and predict future trends in DOM

To document

Abstract

The seed predator Argyresthia conjugella Zeller has rowan as its preferred host plant. In years of poor fruiting in rowan, it oviposits on apples. To improve the knowledge of this apple pest, rowanberries were collected from localities all over Norway from 1971 to 1985, and seed predators and their parasitoids were allowed to emerge for up to five years. Two species of seed predators, A. conjugella and Megastimus brevicaudis Ratzeburg, and seven species of parasitic Hymenoptera were common. The distribution of these species is shown on EIS (European Invertebrate Survey) maps of Norway. The biology of the parasitoids is summarized based on the published literature and their behavior during emergence. The tendency for delayed emergence, which is an indication of prolonged diapause, was more pronounced in M. brevicaudis than in A. conjugella, the former appearing in all five years. Five of the parasitoids also delayed their emergence, and three of them to a high degree, up to five years. Prolonged diapause must be taken into account in studies of rowanberry insect guilds.

To document

Abstract

The present research was undertaken to investigate polyphenolic profiles of peel, pulp and juices made from two standard commercial and five traditional apple cultivars from Bosnia and Herzegovina. The main goal of the study was to monitor the distribution and changes of polyphenolic profiles through different phases of apples’ processing into cloudy and clear juices, with regard to L-ascorbic acid pretreatment. Quantitative determination of phenolic compounds was carried out by using high-performance liquid chromatography with diode-array detection. The obtained results showed that traditional cultivars, namely ‘Paradija’ and ‘Prijedorska zelenika’, displayed significantly higher content of these compounds compared to commercial ones. Flavan 3-ols and flavonol glycosides were mostly found in peels of all cultivars (21.2–44.1 and 5.40–33.3%, respectively), while phenolic acids along with flavan 3-ols were predominant in the pulp (8.20–30.8 and 5.10–13.9%, respectively). Apples’ processing into juices caused decrease (more than 90%) in the content of all polyphenols and the distribution of these compounds from fruits to final products had a negative trend, particularly evident in clear juices. The most drastic loss occurred in the flavonol glycosides and dihydrochalcones content, while chlorogenic acid displayed quite stable distribution from apples to final products due to its good solubility. Apple mash pretreatment with L-ascorbic acid had a positive impact on the preservation and retention of polyphenols.

To document

Abstract

Biomass pyrolysis is the anoxic thermal conversion of biomass into a carbon rich, porous solid, often called biochar. This could be a better waste management alternative for contaminated organic wastes than incineration, due to the useful properties of biochar and potential for carbon sequestration. There are, however, concerns about the potential formation/destruction of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). Six organic wastes, including digested sewage sludges, wood wastes, and food waste reject, were pyrolyzed (500–800°C) in a full-scale relevant unit (1–5 kg biochar hr−1). Removal efficiencies for PCBs and PCDD/Fs were > 99% in the produced biochars. Biochar PAH-content (2.7–118 mgkg−1) was not significantly correlated to feedstock or temperature. PAHs (2563–8285 mgkg−1), PCBs (22–113 µgkg−1), and PCDD/Fs (1.8–50 ngTEQ kg−1) accumulated in the pyrolysis condensate, making this a hazardous waste best handled as a fuel for high temperature combustion. Emission concentrations for PAHs (0.22–421 µgNm−3) and PCDD/Fs (≤2.7 pgTEQ Nm−3) were mainly associated with particles and were below the European Union’s waste incineration thresholds. Emission factors ranged from 0.0002 to 78 mg tonne−1 biochar for PAHs and 0.002–0.45 µgTEQ tonne−1 biochar for PCDD/Fs. PCDD/F-formation was negligible during high temperature (≥500 °C) biomass pyrolysis (69–90% net loss)