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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.

2019

Sammendrag

Glansbiller er de viktigste skadedyrene i oljevekster, og større angrep kan forårsake store økonomisk tap på grunn av redusert skulpedannelse. De siste årene har billene utviklet resistens mot kjemiske midler mange steder, og det skaper utfordringer for bekjempelsen

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Sammendrag

The present study described a droplet-vitrification cryopreservation for shoot tips of shallot (Allium cepa var. aggregatum), a small bulb onion. Shoot tips taken from in vitro stock shoots were precultured with 0.3 M and 0.5 M of sucrose, with 1 day for each concentration. Precultured shoot tips were treated with a loading solution containing 2 M glycerol and 0.6 M sucrose for 20 min and then exposed to plant vitrification solution 3 (PVS3) at 24 °C for 3 h of dehydration. Following exposure to PVS3, shoot tips were moved onto 5.0 μl PVS3 droplets on aluminum foil strips, followed by direct immersion into liquid nitrogen for 1 h. Frozen shoot tips were thawed by incubation in liquid MS medium containing 1.2 m sucrose for 20 min at room temperature, and then post-thaw cultured for shoot regrowth. Exposure of the shoot tips to PVS3 produced shoot regrowth (58%). Differential scanning calorimetry (DSC) detected 1.8% of freezable water in the shoot tips that had been dehydrated by PVS2, and no freezable water in those by PVS3 treatment. Exposure to PVS3 provided a broader safe temperature range (− 196 °C to − 88 °C), compared to that (− 196 °C to − 116 °C) of PVS2, for cryopreserved samples. Histological observations found that PVS3 dehydration allowed many cells in the apical dome and in the leaf primordia to survive following freezing in LN, while PVS2 dehydration resulted in much fewer surviving cells in the apical dome. The droplet-vitrification cryopreservation produced 56%, 72% and 32% shoot regrowth in cryopreserved shoot tips taken from in vitro shoots, adventitious buds regenerated from stem discs and field-grown bulbs, respectively. Advantages and disadvantages of the use of different source explants for cryopreservation were discussed. The droplet-vitrification cryopreservation produced 45% and 70% shoot regrowth in the additional two shallot genotypes ‘Kverve’ and ‘Lunteviga’. The results obtained in this study provide technical supports for setting-up cryo-bankings of genetic resources of shallots and other Allium species.

Sammendrag

Potato (Solanum tuberosum L.) is one of the most important crops grown in Norway, and virus-free plants are required for commercial potato production and for preservation of potato germplasm. The present study evaluates three in vitro therapies – meristem culture, cryotherapy, and chemotherapy combined with thermotherapy – to eliminate viruses from eight historically valuable potato cultivars belonging to the Norwegian potato germplasm. Potato virus Y, potato virus M, potato virus X and potato virus S were present in eight selected old potato cultivars due to long-term conservation in open field. Double-antibody sandwich enzyme-linked immunological assay (DAS-ELISA) and biological indicators were the standard tests used to confirm virus infection in our study. Six virus-free plants from four potato cultivars were obtained after meristem culture, and no virus-free potato cultivars were obtained after cryotherapy. Virus-free frequency for eight different potato cultivars after combining chemotherapy with thermotherapy varied from 36.4% to 100%, with single virus elimination rates of between 74.2% and 92.9%. Chemotherapy compared with thermotherapy was the most effective of the three in vitro therapies used in this study. Highly sensitive small RNA high-throughput sequencing (HTS) was used to evaluate the virus status of potato virus-free materials after virus eradication, and no virus was found, which was consistent with the results of DAS-ELISA and biological indicators. Small RNA HTS has been reported for the first time to evaluate the virus status after virus elimination and to control virus-free potato nuclear stocks.

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Sammendrag

Field and laboratory studies show increased leaching of pesticides through macropores in frozen soil. Fast macropore flow has been shown to reduce the influence of pesticide properties on leaching, but data on these processes are scarce. The objective of this study was to investigate the effect of soil freezing and thawing on transport of pesticides with a range of soil sorption coefficients (Kf). To do this we conducted a soil column study to quantify the transport of bromide and five pesticides (2-methyl-4-chlorophenoxyacetic acid, clomazone, boscalid, propiconazole, and diflufenican). Intact topsoil and subsoil columns from two agricultural soils (silt and loam) in southeastern Norway were used in this experiment, and pesticides were applied to the soil surface in all columns. Half the columns were then frozen (−3°C), and the other half were left unfrozen (4°C). Columns were subjected to repeated irrigation events where 25 mm of rainwater was applied during 5 h at each event. Irrigations were followed by 14-d periods of freezing or refrigeration. Percolate was collected and analyzed for pesticides and bromide. Pesticide leaching was up to five orders of magnitude larger from frozen than unfrozen columns. Early breakthrough (<<1 pore volume) of high concentrations was observed for pesticides in frozen columns, indicating that leaching was dominated by preferential flow. The rank order in pesticide leaching observed in this study corresponded to the rank order of mean Kf values for the pesticides, and the results suggest that sorption plays a role in determining leaching losses even in frozen soil.