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.
2016
Sammendrag
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Forfattere
Håvard Steinshamn Steffen Adler Randi Berland Frøseth Tor Lunnan Torfinn Torp Anne Kjersti BakkenSammendrag
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Forfattere
Ingunn Burud Christophe Moni Andreas Svarstad Flø Cecilia Marie Futsæther Markus Steffens Daniel RasseSammendrag
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Forfattere
Inger Maren Rivrud Richard Bischof Erling Meisingset Barbara Zimmermann Leif Egil Loe Atle MysterudSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Helga Amdahl Trygve S. Aamlid Åshild Ergon Mallikarjuna Rao Kovi Petter Marum Muath K Alsheikh Odd Arne RognliSammendrag
While tetraploid plants of red clover are taller, have thicker stems, and have broader leaves that altogether result in a higher forage yield compared to diploids, they generally have substantially lower seed yields than diploid plants. Tetraploid red clover can be induced chemically by colchicine or nitrous oxide (N2O) and sexually by union of unreduced gametes. The average seed yield of tetraploid red clover in Norway is 60% of the diploid yield, while in Sweden it is 75%. One objective of this paper was to examine whether there is a difference in seed yield among chromosome doubled tetraploids and crossed tetraploids. A second objective was to investigate differences in seed yield and seed yield components in Norwegian and Swedish tetraploid populations. The third objective was to study which yield component most correlates with the seed yield per hectare. Seed production experiments were established at Landvik and Bjørke in Norway and Svalöv and Lännäs in Sweden. Populations made by crossings of tetraploids gave significantly greater yield (p < 0.001) compared to populations that were made by chromosome doubling. On average, Norwegian and Swedish varieties had equal yields in both experimental years. Norwegian and Swedish varieties differed mostly in earliness traits. Swedish populations began flowering on average 4 d earlier than Norwegian populations. Genotypic correlations showed that seed yield per flower head was the component with the highest correlation (r = 0.956 and r = 0.977) with yield per hectare in both experimental fields. Results from the second experimental year indicate a trend towards improved seed yield after several cycles of recurrent selection for higher seed yield per flower head.
Forfattere
Tomasz Leszek Woznicki Kjersti Aaby Anita Sønsteby Ola M. Heide Anne-Berit Wold Siv Fagertun RembergSammendrag
The effects of postflowering temperature and daylength on the concentration of individual phenolic compounds were studied in black currant (Ribes nigrum L.) berries under controlled phytotron conditions. The four cultivars studied varied greatly in their concentrations of individual phenolic compounds and temperature stability for accumulation. The concentrations of a wide range of identified phenolic compounds were strongly influenced by temperature over the 12–24 °C range, often with opposite temperature gradient patterns for compounds within the same subclass. Accumulation of anthocyanins and flavonols increased under natural long day conditions, which provided an increased daily light integral, while under identical light energy conditions, photoperiod had little or no effect on the concentration of phenolic compounds. Furthermore, with the exception of members of the hydroxycinnamic acid subclass, the concentration of most phenolic compounds was higher in berries ripened outdoors than in the phytotron, apparently due to screening of UV-B radiation by the glass cover.
Forfattere
Sigridur Dalmannsdottir Marcin Rapacz Marit Jørgensen Liv Østrem Arild Larsen Rolf Rødven Odd Arne RognliSammendrag
The expected temperature rise in late summer/early autumn can change the conditions for acclimation and affect the winter survival of perennial crops. This study examined the effect of the temperature just before the onset of cold acclimation (pre-acclimation) on freezing tolerance of timothy (Phleum pratense L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.) populations (both cultivars and breeding populations) adapted to either northern or southern parts of Norway. Using phytotron experiments, we studied whether increasing pre-acclimation temperature delays growth cessation, affects photoacclimation and reduces freezing tolerance. Furthermore, we assessed whether these effects were related to the latitudinal adaptation of the plant material. The results showed that a rise in pre-acclimation temperature decreased both cold acclimation capacity and photoacclimation in these species. This affected the freezing tolerance, which was reduced significantly more in northern-adapted population of timothy and perennial ryegrass compared with southern-adapted populations. Red clover was less affected by temperature changes than the grasses.
Forfattere
Miren del Rio Hans Pretzsch Iciar Alberdi Kamil Bielak Felipe Bravo Andreas Brunner Sonia Condes Mark J Ducey Teresa Fonseca Nikolas Von Lüpke Maciej Pach Sanja Peric Thomas Perot Zahera Souidi Peter Spathelf Hubert Sterba Martina Tijardovic Margarida Tome Patrick Vallet Andres Bravo-OviedoSammendrag
The growth and yield of mixed-species stands has become an important topic of research since there are certain advantages of this type of forest as regards functions and services. However, the concepts and methods used to characterize mixed stands need to be understood, as well as harmonized and standardized. In this review we have compiled a set of measures, indices, and methods at stand level to characterize the structure, dynamics, and productivity of mixed stands, and we discuss the pros and cons of their application in growth and yield studies. Parameters for the characterization of mixed stand structure such as stand density, species composition, horizontal (intermingling) and vertical tree distribution pattern, tree size distribution, and age composition are described, detailing the potential as well as the constraints of these parameters for understanding resource capture, use, and efficiency in mixed stands. Furthermore, a set of stand-level parameters was evaluated to characterize the dynamics of mixed stands, e.g. height growth and space partitioning, self- and alien-thinning, and growth partitioning among trees. The deviations and changes in the behaviour of the analysed parameters in comparison with pure stand conditions due to inter-specific interactions are of particular interest. As regards stand productivity, we reviewed site productivity indices, the growth–density relationship in mixed stands as well as methods to compare productivity in mixed versus monospecific stands. Finally, we discuss the main problems associated with the methodology such as up-scaling from tree to stand level as well as the relevance of standardized measures and methods for improving forest growth and yield research in mixed stands. The main challenges are also outlined, especially the need for qualitatively sound data.