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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

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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

Occasionally, high mycotoxin levels are observed in Norwegian oat grain lots. The development of moderate resistant oat cultivars is therefore highly valued in order to increase the share of high quality grain into the food and feed industry. The Norwegian SafeOats project (2016-2020) aims to develop resistance screening methods to facilitate the phase-out of Fusarium-susceptible oat germplasm. Furthermore, SafeOats will give new insight into the biology of F. langsethiae and HT2+T2 accumulation in oats. The relative ranking of oat varieties according to F. graminearum/DON versus F. langsethiae/HT2+T2 content has been explored in naturally infested as well as in inoculated field trials. Routine testing of the resistance to F. graminearum in oat cultivars and breeding lines has been conducted in Norway since 2007. We are currently working on ways to scale up the inoculum production and fine tune the methodology of F. langsethiae inoculation of field trials to be routinely applied in breeding programs. Through greenhouse studies, we have analysed the content of Fusarium DNA and mycotoxins in grains of selected oat varieties inoculated at different development stages. Furthermore, we are studying the transcriptome during F. langsethiae and F. graminearum infestation of oats. The project also focus on the occurrence of F. langsethiae in oat seeds and possible influence of the fungus on seedling development in a selection of oat varieties. On average, the fungus was observed on 5% of the kernels in 168 seed lots tested during 2016-2018. No indication of transmission of F. langsethiae from germinating seed to seedlings was found in a study with germination of naturally infected seeds. So far, the studies have shown that the ranking of oat varieties according to HT2+T2 content in non-inoculated field trials resembles the ranking observed in inoculated field trials. The ranking of oat varieties according to DON content is similar in non-inoculated and F. graminearum inoculated field trials. However, the ranking of oat varieties according to DON content does not resemble the ranking for HT2+T2. The results from SafeOats will benefit consumers nationally and internationally by providing tools to increase the share of high quality grain into the food and feed industry. The project is financed by The Foundation for Research Levy on Agricultural Products/Agricultural Agreement Research Fund/Research Council of Norway with support from the industry partners Graminor, Lantmännen, Felleskjøpet Agri, Felleskjøpet Rogaland & Agder, Fiskå Mølle Moss, Norgesmøllene, Strand Unikorn/Norgesfôr and Kimen Seed Laboratory.