Inger Martinussen

Effects of Temperature and Photoperiod on Yield and Chemical Composition of Northern and Southern Clones of Bilberry (Vaccinium myrtillus L.)

After pollination outdoors, individual bilberry plants from two Northern and two Southern clones were studied for climatic effects on berry yield and quality in a controlled phytotrone experiment at 12 and 18 °C. At each temperature, the following light treatments were tested: (1) 12 h natural light, (2) 24 h natural light, and (3) 24 h natural light plus red light. The first experimental year there was no difference in yield between temperatures; however, the second experimental year the berry yields was significantly higher at 18 °C. Berry ripening was faster in the Northern than in the Southern clones at 12 °C. Northern clones also showed significantly higher contents of total anthocyanins, all measured anthocyanin derivatives, total phenolics, malic acid and sucrose. Metabolic profiling revealed higher levels of flavanols, hydroxycinnamic acids, quinic acid and carbohydrates at 12 °C.

Phytochrome Overexpression and Cold Hardiness in Transgenic Populus

Photoperiodic effects on woody plants were reported already by Gardner and Allard in 1923 and comprehensive studies during the ’50s confirmed the role of photoperiod as an important environmental regulator of growth and growth cessation in many northern tree species (Nitsch, 1957; Wareing, 1956). In woody plants cessation of apical growth is a prerequisite for cold acclimation (Weiser, 1970) and photoperiod, as a factor controlling growth cessation, is therefore an important environmental signal for initiation of cold acclimation. In many cases a proper timing of acclimation and deacclimation, in respect to annual variation of temperature conditions, is more critical for winter survival than the maximum level of frost hardiness. Also in such coniferous species where cessation of apical growth is not controlled by photoperiod, short photoperiod is necessary for good cold acclimation, low temperature causes no or only a limited level of hardiness if combined with long day conditions (Schwarz, 1970; Aronsson, 1975; Christersson, 1978; Jonsson et al., 1981). Thus, photoperiod may have both an indirect, through induction of growth cessation, and a more direct influence on cold acclimation in woody plants.

Effect of fertilization, tiller cutting and environment on plant growth and yield of European Blueberry (Vaccinium myrtillus L.) in Norwegian forest fields.

BACKGROUND: European blueberry (E. blueberry; Vaccinium myrtillus L.) is a natural resource demanded by the processing industry with potential of domestication. Therefore an investigation of the possibilities of partial cultivation of native stands was started. OBJECTIVE: To increase knowledge of how E. blueberry react to soil types, climate, mineral nutrition, organic amendments and cutting of tillers. METHODE: Five forest fields with E.blueberry stands in Norway were examined. Besides natural development influenced by soil parameters and climate, effect of fertilization and plant pruning were examined in the municipalities of Bardu in Troms county (68◦N) and of Snasa and Lierne in Nord-Trondelag county (64◦N). Experiments were executed in randomized block designs in forest fields of native E. blueberry stands. RESULTS: The fields that performed best had O-layers close to 7 cm or thicker. The C/N ratios indicate that N was not easily available in any field, and addition of mineral fertilizer containing nitrogen and phosphor show that especially N increased elongation of long shoots and more nodes were developed. However, the effect on number of short shoots per long shoot initiated a growth gain only the last of two years. The positive growth effect of fertilizer was not followed by higher yields throughout the years, and strongest fertilization level (N60P40) reduced yield in average of four years. Adding composted wood chips or wood chips alone increased tiller growth in the birch-field in Bardu both years, but only the first year in the pine-field; this was not reflected in higher yield. Cutting of shoots to the ground reduced yield and full yield potential was not recovered before the third year after cutting. CONCLUSION: The results suggest that by improving growth conditions, especially by securing a thick natural O-layer and adjusting soil macro nutrient composition, growth conditions could be improved; and that fruit yield were down the two first years after pruning.

Assessing the Influence of Genotype and Temperature on Polyphenol Composition in Cloudberry (Rubus chamaemorus L.) Using a Novel Mass Spectrometric Method

A high-throughput abbreviated liquid chromatography mass spectrometric (ACMS) method was used to assess the relative influence of genotype and temperature on polyphenol composition in cloudberries. Principal component analysis (PCA) plots of the collated ACMS data showed a separation between crosses based on their female parents (Nyby or Fjellgull). Crosses with Nyby as the female parent had higher relative levels of masses assignable to certain ellagitannin derivatives. Crosses with Fjellgull had higher levels of distinctive masses assignable to quercetin derivatives (including a hydroxy-3-methylglutaroyl hexose derivative not previously identified in cloudberry) and anthocyanin derivatives. There was also a separation between samples grown at lower and higher temperatures, which was driven by m/z signals associated with ellagitannins and notably a major component, sanguiin H-6. Therefore, abbreviated MS techniques can discern genetic and/or environmental influences in polyphenol composition and can quickly assess quality in breeding programmes or in response to environmental changes.

Nutritional composition of bilberries (Vaccinium myrtillus L.) from forest fields in Norway - Effects of geographic origin, climate, fertilization and soil properties

Effects of different environmental factors (origin, climate, fertilization and soil properties) on berry nutritional quality were studied in eight forest fields of bilberry ( Vaccinium myrtillus ) in Northern-, Mid- and Southern Norway. No clear trend between locations could be found, however untargeted multivariate analysis of metabolite profiles revealed clear segregation patterns between locations. Anthocyanin, and phenolics content, and titratable acidity were significantly affected by mineral fertilization (Mid-Norway), while organic fertilization did not show any significant effects (Northern Norway). Bilberry chemical composition was affected by harvest time point, as indicated by a potentially higher nutritional quality regarding the content of phytochemicals when harvesting at mid or towards the end of the production season (Southern Norway). Regional and annual climate had strongest impact on the nutritious content of bilberries. Significant differences were found between locations, however previous findings on increasing anthocyanin content with latitude were not confirmed due to environmental impacts confounding the population effects.

METABOLITE PROFILING OF BILBERRIES (VACCINIUM MYRTILLUS L.)

Norwegian Institute for Agricultural and Environmental Research, Bioforsk Nord Holt, Box 2284, N-9269 Tromso, Norway The Plant Biocentre, Department of Biology, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway Department of Biology, University of oulu, PoB 3000, FIN-90014 oulu, Finland University of Nova Gorica, Wine Research Centre, Vipavska 11c, SI-5270 Ajdovscina, Slovenia Institute of Biology, University of Tromso, N-9037 Tromso, Norway

Evaluation of cloudberry (Rubus chamaemorus L.) clones for selection of high-quality varieties

Abstract Two female and two male cultivars of cloudberry (Rubus chamaemorus L.) have previously been released as a result of clone evaluation at the Norwegian Institute for Agricultural and Environmental Research. Selection criteria have been number of pistils or stamens per flower, number of flowers and number of shoots per m2. Recently two groups of clones have been evaluated with the aim of finding new cultivars for release. The clones were collected at different locations in Norway, as well as in England and at Svalbard. Results from harvesting in 2005 to 2008 show large genetic variation in all evaluated traits and indicate good production potential for some of the tested clones. Previously released ‘Fjellgull’ and ‘Fjordgull’ are confirmed as stable and high producing. Of the clones evaluated for the first time, especially clone 102 and clone 306 are possible contenders for release. In addition to prior selection criteria based on berry yield, berry contents also have been analysed. The results indicate that clones with a northern origin have higher levels of total phenols, total anthocyanins and carotenoids than clones of a southern origin.

Seasonal and yearly variation of total polyphenols, total anthocyanins and ellagic acid in different clones of cloudberry (Rubus chamaemorus L.)

Cloudberry (Rubus chamaemorus L.) is a wild perennial shrub growing on peatland with a circumpolar distribution. The combined berries have a high polyphenol content comprised primarily of ellagitannins. A few commercial cultivars are available, and pre-breeding trials on clonal material from different geographical origins are in progress. The objective of this study was to investigate how the content of polyphenols of four different cloudberry cultivars were affected by harvesting time and climatic variations during a 3-year-period. Plants were grown outside in plots and berries were harvested when mature. Berries were analyzed for total polyphenols and total anthocyanins by spectrophotometer. Total ellagic acid was identified and quantified using HPLC-MS after hydrolysis of the extracts. Results showed that all measured parameters; total anthocyanins, total polyphenols and ellagic acid are strongly influenced by the genetic background. Although low anthocyanin contents were present in all genotypes, they were highly affected by climatic conditions, being highest at low temperatures. However, the content of ellagic acid was less affected by environmental conditions and showed little response to changing temperatures. In conclusion, ellagitannin content was the most dominating polyphenol group observed in this study and was affected by genetics and is therefore a good breeding criterion for increased health benefit of cloudberry.

Effect of combined seasonal coverage on northern production of strawberry (Fragaria ananassa Duch)

Ulenberg E., Martinussen I., Samuelsen R.T. (2017): Effect of combined seasonal coverage on northern production of strawberry (Fragaria ananassa Duch). Hort. Sci. (Prague), 44: 148–155. Two field trials with five strawberry cultivars planted on a woven black polyfibre ground cover sheet with or without translucent sheet plant coverage during winter and the growing season as combined treatments were started in 2004 and 2005. In total, nine different cultivars were included in the two fields. One early cv. ‘Polka’ and one late cv. ‘Korona’ acted as standard cultivars, while the other cultivars were new, named or labelled selections from Norwegian, Finnish and Swedish breeding programs. Winter survival, spring vigour, earliness, saleable and total berry yield, berry size and berry quality were registered for three years. The cultivars differed in earliness, berry size, yield (gram per plant) and total production (sum of all years). A combination of fibre sheet winter and spring coverage and more open net sheet harvest season coverage showed favourable results for overwintering, earliness and berry yield, and enhanced the ripening process in all cultivars.

Levels of individual anthocyanins and hydroxycinnamic derivates in selected clones of cloudberry (Rubus chamaemorus)

Abstract Cloudberry (Rubus chamaemorus) is a dioecious perennial shrub growing on peat land. The berries are a combined fruit with a color ranging from yellow to orange and bright red. Berries are highly valued in the Nordic countries and berries with orange to red color are preferred. Cultivation and breeding has started, and four Norwegian varieties are on the market. These clones were selected on the basis of good shoot production (both sexes), good pollinators (males), and big berries (females). Recently, berry quality has been introduced in breeding programs as a trait for selection. In this study we present the variation in levels of individual anthocyanins and hydroxycinnamic derivates between different clones of cloudberry. Both levels of anthocyanins and hydroxycinnamic derivates varied considerably between the different clones. The most abundant anthocyanin was cyanidin 3-glucoside, followed by cyanidin 3-rutinoside. One single clone (AN1372) from Andøya in Northern Norway had the highest levels of all the analyzed anthocyanins. Among the two analyzed hydroxycinnamic acids, p-coumaric acid presented the highest ratio in all analyzed berries. Differences between different years were relatively high, but not consistent. Levels of caffeic acid did not vary much between clones. The results indicate a genetic basis for the variation between clones, but since numbers of samples were few and sampling only were done during two growth seasons, further analysis will be needed to examine the variation and genetic basis of anthocyanin composition of cloudberry.