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.
2010
Sammendrag
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Sammendrag
Plants use an array of responses to pathogenic infection. Understanding of the underlying defence mechanisms may lead to new strategies for reducing the damage. Our objective here was to study histological and cytological responses in Norway spruce of different ages (from seedlings to mature trees) to infection with several pathogenic organisms (Pythium dimorphum, Ceratocystis polonica and Heterobasidion annosum) and compared them to effects of mechanical wounding. To visualize the reaction on infection/wounding we used different histological staining techniques followed by laser confocal microscopy and TEM. Primary roots of Norway spruce seedlings were infected with P. dimorphum, while mature trees (about 30 years old) were infected with C. polonica, H. annosum and wounded. In seedling roots the hyphae of P. dimorphum penetrated the tissue rapidly and colonized the root within 24 hours. In the infected tissue the lignin concentration doubled within 6 days compared to non infected roots. General response to infection by C. polonica and H. annosum in mature trees was the production of lignosuberised wound periderm, accumulation of polyphenolic aggregates in living parenchyma cells in the phloem and development of traumatic resin ducts in the xylem. Upon wounding, we observed a similar, but less intense response. In conclusion, although we tested fungi belonging to different taxonomical and ecological groups, the responses were similar, differing in intensity and timing of the defence response mainly. The response seems to be similar but dependent on the degree of susceptibility in the individual trees and clones.
Sammendrag
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Forfattere
Roman Gebauer Josef Urban Isabella Børja Vladimir Gryc H Vavrcik Daniel Volarik Petra RychteckaSammendrag
The drought stress presents a significant threat for the forest ecosystems. The climate change brings some extreme climatic conditions including longer and more common periods of the drought into the still more forest stands. Current forest management and consecutively wood processing industry in the Czech Republic is nowadays dependent mostly on the Norway spruce. In the same hand, Norway spruce is probably the most threatened tree species by the climate change. Therefore there is a demand for the suitable methodology to monitor the direct effect of the drought on the trees. Presented publication puts together different methods of the evaluation of the water stress and tries to assess their value for the study of the water stress. Of course, there are dozen of the methods to study the water stress. In this handbook we skipped the difficult and expensive techniques and focused rather on the simple methods, suitable for the field use. Methodology begins with the description of the meteorological measurements with current widely available instrumental techniques (i.e. measurements of the intensity of global radiation, air temperature and humidity, wind speed and precipitation) and continues with the monitoring of the soil water content and soil water potential. Then there is a focus on the direct effect of the water stress on the plant. We began with the plant root system since we believed that the fine roots were the most susceptible part of the tree. The focus was on their morphology, anatomy and biological activity. In the aboveground part of the tree we focused on the development of the hydraulic architecture of the tree on the microscopic level. This theoretical analysis was validated by the in-situ measurements of the sap flow. Direct and immediate effect of the water stress on the plant water status is described in the means of the plant water potential. Similarly to the hydraulic architecture we dealt with both the xylogenesis (on the cellular level) and the stem increment measured (on the tree level) by the logging band dendrometers. Finally we discussed the effect of the plant water status on the mineral nutrition of the tree. To conclude, none of the methods alone can implicate the complexity of the water stress, however the combination of the different views gives rather good insight on the tree condition and enable to predict the further tree development.
Sammendrag
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Sammendrag
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Sammendrag
Results from 4 field trials, see full poster in attached file
Sammendrag
Artikkelen oppsummerer resultatene fra 8 norske sprøyteforsøk med konvensjonelle og alternative midler mot bringebærbladmidd (Phyllocoptes gracilis) siden 2005. Denne midden er et stort problem i "Glen Ample". To høstsprøytinger med rapsolje+grønnsåpe eller svovel har i forsøkene hatt opp mot 100 % effekt på overvintrende bladmidd rundt knoppene. Riktig sprøyteteknikk og god væskemengde er trolig avgjørende for så gode resultater. Når sprøytevæsken renner nedover stengelen og samler seg i restene av bladstilkene rundt neste års knopper, får bladmidden seg et dødelig bad. Ved å kombinere slik høstsprøyting og sprøyting med et vanlig middmiddel i tiden før blomstring bør det være mulig å få bladmidden under kontroll.
Sammendrag
Artikkelen oppsummerer resultatene fra 8 norske sprøyteforsøk med konvensjonelle og alternative midler mot bringebærbladmidd (Phyllocoptes gracilis) siden 2005. Denne midden er et stort problem i "Glen Ample". To høstsprøytinger med rapsolje+grønnsåpe eller svovel har i forsøkene hatt opp mot 100 % effekt på overvintrende bladmidd rundt knoppene. Riktig sprøyteteknikk og god væskemengde er trolig avgjørende for så gode resultater. Når sprøytevæsken renner nedover stengelen og samler seg i restene av bladstilkene rundt neste års knopper, får bladmidden seg et dødelig bad. Ved å kombinere slik høstsprøyting og sprøyting med et vanlig middmiddel i tiden før blomstring bør det være mulig å få bladmidden under kontroll.
Forfattere
Nina TrandemSammendrag
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