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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.

2024

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Sammendrag

By optimizing size of shoot tips, preculture medium and exposure duration to PVS2, we established an efficient and wide-spectrum droplet-vitrification cryopreservation for shoot tips of raspberry (Rubus idaeus L.). This protocol yielded 80–100% and 67–100% of survival and shoot regrowth levels in cryopreserved shoot tips across 23 raspberry genotypes. Genetic integrity was assessed in cryo-derived regenerants after 3 months of post-cryopreservation using inter simple sequence repeat (ISSR), single nucleotide polymorphism (SNPs), and insertions and deletions (InDels). ISSR did not detect any polymorphic bands in the cryo-derived regenerants. Although the number of SNPs and InDels decreased in the cryo-derived regenerants, variation trends were similar between the cryo-derived regenerants and the control. Plant vegetative growth and root growth were assessed in the cryo-derived plants after 9 weeks of growth in greenhouse. There were no significant differences in plant vegetative growth measured by plant height, number of fully-opened leaved, leaf area, and fresh and dry weight between the cryo-derived plants and the control, although significant differences were observed in root growth measured by root total length, root average diameter and root volume between the two types of plants. The results obtained in the present study indicate that the droplet-vitrification method has great potential for cryopreservation of raspberry germplasm.

Sammendrag

Successful introduction of the new cultivars requires proper pomological, phenological and as well as technological evaluation. It is particularly important at the harsh Norwegian climate conditions. Investigations were conducted with apple cultivar ‘Eden‘ / ‘Wursixo‘ (WUR 6), with the aim to establish an optimal balance between yield, fruit quality and bearing regularity. Four different crop load levels were tested in 3 consecutive years in the orchard planted 3.5 x 1 m and trained as slender spindle. Lower crop load levels guaranteed good return bloom, a very high share of fruits harvested during the first picking, and larger fruits. Increasing crop load led to less intensive return bloom, smaller fruit sizes and higher share of fruits harvested during the second picking. It was found that ‘Eden‘ is strictly alternating cultivar and precise crop load levels according to the tree age and tree vigour were defined. In order to keep ‘Eden‘ trees in regular bearing mode crop load levels should be maintained at 4.5-5 fruits cm-2 of trunk cross-sectional area (TCSA) in the 3rd and 6-7 fruits in the 4th growing season

Sammendrag

Timothy ( Phleum pratense L.) is the predominant forage grass species in the northern parts of the Nordic region. Because of the long andharsh winters and a short growing season, most of it with continuous light, the need for locally adapted timothy seed has been recognizedfor more than a century. However, the seed production of timothy in these marginal environments is unpredictable with acceptable seedyield and quality on average only every third year. Thus, a multiplication scheme for the northern cultivars was established with only pre-basic seed produced in the north, and basic and certified seed produced further south to secure enough seed of good quality. In recentdecades this scheme has been more or less abandoned with continous generations produced in the south. Farmers are complaining andare questioning whether the cultivars has changed and lost winter hardiness. We studied freezing and ice-encasement tolerance of generations of the the northern timothy cultivars ‘Engmo’ (old landrace) and ‘Noreng’(synthetic) multiplied for one, two or three generations in Central, Southern and Northern Norway. The trials introduce very largedifferences in mean temperature, growing degree days and photoperiod between place of parental origin and sites of multiplication so theeffects on fitness observed could arise from both selection and and induced epigenetic changes. Large changes (loss) in freezing and ice-encasement tolerance were observed, especially at the southern location in the first generation.The cultivars behaved differently and there were significant interactions. The extreme phenotypic changes observed might be explained bygenetic selection or epigenetic memory of the environmental conditions experienced during seed production, or a combination of the two.We are currently analysing GBS data of all generations and this will be used to test whether genetic shifts has occured during themultiplication in the different environments.