Browsing by Subject "raspberry"

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  • Roininen, Aino Elina Sylvia (Helsingin yliopisto, 2018)
    Raspberry is prone to virus infections but diversity and occurrence of different raspberry viruses in Finland is still largely unknown. The purpose of this thesis work was to reveal which viruses are troubling raspberry varieties that are part of Finnish raspberry genetic resources and have been maintained in vivo on the field. The study also examines and compares siRNA diagnostics to traditional PCR method in detection of raspberry viruses. PCR, cloning, and traditional Sanger sequencing are used to get more detailed information of the virus strains, and scratch the surface of phylogenetic diversity of raspberry viruses that were detected in this study. siRNA detection of was accurate and effective with Black raspberry necrosis virus (BRNV), Raspberry bushy dwarf virus (RBDV) and Rubus yellow net virus (RYNV), but VirusDetect program couldn’t find Raspberry vein chlorosis virus (RVCV) that was positive in Velvet analysis and molecular diagnostics. Sequencing and phylogenetic analysis revealed RYNV strain that was like Canadian isolate (KF241951.1). Many new Badnavirus-like sequences were detected, but possible integration of Badnaviruses into raspberry genome was not excluded in this study. BRNV isolates were closely related to previously detected Finnish BRNV isolates. RVCV isolates grouped to three clades where RVCV from sample 21 was the most similar to formerly sequenced Scottish isolate (FN812699.2). Multiple viral infections were detected in one sample amongst these raspberry varieties, which may indicate different kinds of virus-virus interactions. The most important finding of this study was that RYNV and RVCV are present in Finland. Secondly all the detected raspberry viruses are genetically diverse and multiple infections of detected virus species are common.
  • Pohjola, Minna (Helsingfors universitet, 2013)
    Red raspberry (Rubus idaeus L.) is one of the most important berry crops economically in Finland but the profitability is weakened due to frequent winter injuries and varying yields. Protected berry production has lately become the main cultivation method of raspberries in Europe. Long cane raspberry is a special plant type that has been induced to flower and cold stored to produce a harvest in the year of planting. Specifically designed for protected cropping raspberry long canes have been shown to possess a very high cropping potential. The aim of this study in the first experiment was to examine the effect of growing conditions, primocane and floricane number and storage time on yield of red raspberry long canes. Raspberries were grown in an open field and in a tunnel with varying cane numbers (1 or 2). After cold storage they were forced in a plastic tunnel and new shoots were allowed to grow alongside the floricanes. The canes grown in a tunnel yielded 56 % more compared to those grown outdoors. The plants with two floricanes yielded 39 % more compared to plants with only one floricane but their average berry weight was 0,6 g lower. Presence or absence of primocanes didn’t have an effect on the yield or other growth parameters of the floricanes. In the second experiment plants were grown in an open field and in a tunnel and cold stored for three different periods of 4, 12 or 20 weeks. After storage the plants were forced to flower in a greenhouse. The cropping potential of the plants stored for 20 weeks (977 flowers/plant) was almost three times as high compared to those stored for only 4 weeks (332 flowers/plant). Plants that had been stored for 20 weeks also produced 138 % more laterals that were 14 % longer than plants stored for 4 weeks. Bud break for plants stored for 20 weeks took place 25 days earlier than for those stored for 4 weeks. Carbohydrate content of raspberry cane is related to its ability to produce a harvest. In this experiment the concentration of soluble carbohydrates increased and the concentration of starch decreased during storage. The total carbohydrate content in the whole plant also decreased during storage and it was 12-40 % higher in plants grown in a tunnel compared to the ones grown in an open field. According to this research it is possible to increase raspberry yields with long cane plants. In the two experiments growing conditions and storage time were found to have the biggest influence on cropping potential. The most optimal long cane plant type based on this research would be a plant with two canes that has been grown in a tunnel and cold-stored 20 weeks at the minimum.
  • Mustalahti, Aino-Maija (Helsingfors universitet, 2011)
    Insect pollination increases seed production and improves the quality of the yield of various crop plants. In berry plants, such as strawberry and raspberry, the size and the quality of the fruits increase by successful insect pollination. Strawberry flowers are mainly not attractive to honeybees but raspberry is one of the main yield crops for honeybees. The aim of the study was to find out, how efficiently honeybees visit strawberry and raspberry flowers, concentrating on the honey bee visits on a single flower during one hour. Honey bees can be used as vectors of Gliocladium catenulatum to control Botrytis cinerea in strawberry and raspberry. The success of vector dissemination and its sufficiency to control Botrytis cinerea is evaluated based on flower visits. The data was collected from six farms in Eastern-Finland near to Suonenjoki, in the summer 2007. The flower visits were calculated during the flowering season of strawberry and raspberry in different weather conditions, times of the day and distances from the bee hives. Flowers were chosen randomly and they had to be open to be selected for observation. The observation time varied according to bee activity on the field. In average, honeybees visited on single strawberry flower 1.75 times per hour, and on single raspberry flower 4.27 times per hour. In both plants there were no significant differences in the flower visits according to the stage of the flowering. Time of the day (hour) correlated negatively with flower visits in both plants and temperature correlated positively to flower visits in both plants. Challenging weather conditions restricted the collecting of the data and the summer was rainy. Despite of that, honeybees visited the flowers of the both plants so that the pollination was proper and the control of Botrytis cinerea was sufficient. When planning the vector dissemination, especially in strawberry, the placement and the adequate number of bee hives should be taken into consideration. The need of nutrition should be great in the hives, to maximize the flower visits. Open brood can be inserted to hives or pollen storages can be removed from the hives to stimulate pollen collection. More information is needed on the effect of hive placement, competing plants and attractiveness of different Finnish strawberry cultivars to flower visits. It could be necessary to determine the nectar and pollen secretion of Finnish strawberry and raspberry cultivars.
  • Pinomaa, Anni (Helsingfors universitet, 2016)
    Protected cultivation of raspberries (Rubus idaeus L.) has increased its popularity in Finland. One reason is that the fruit is extremely sensitive to rainy weather during its development. The raspberry plant itself is sensitive to wind and low temperatures, which can reduce growth. In Europe most of the raspberry is grown in protected cultivation, and this technology is now becoming popular in Finland. A high tunnel is a cost-efficient way to protect the plants against rainy weather and extend the harvest season. The protected cultivation has been shown to increase the yield and cropping potential of raspberry and reduce the gray mold in the berries. In human diet, berries are among the richest sources of antioxidants. In raspberry, the most important antioxidants are vitamin C (20 %) and phenolic compounds (80 %). Among phenolic compounds, ellagitannins and anthocyanins give the greatest contribution to antioxidant activity. The aim of this thesis was to study the yield, sensory quality, nutritional quality and shelf life of three floricane fruiting raspberry cultivars grown in high tunnel and open field. Cultivars ’Glen Ample, ’Glen Dee’ and ’Maurin Makea’ were used in the study. Sugar and acid content of raspberry were examined to get an overview of sensory quality. The nutritional quality was studied with an antioxidant activity assay (using FRAP method) and total phenolics assay (using Fast Blue BB method). The shelf life was tested both in +5 °C and in room temperature. The average total yield per cane was 99 % greater in tunnel than in the open field, whereas both sugar and acid content of the berry were greater in open field. Berry weight and total phenolics content were strongly cultivar dependent characteristics. The results of the antioxidant activity assay did not show significant differences between either growing conditions or the cultivars. The shelf life in room temperature was equally weak for all samples, but in +5 °C storage the open field raspberries developed symptoms of gray mold earlier than those picked from the tunnel. The conclusion is that contents of health beneficial compounds in berries were not affected in tunnel cultivation, but berry taste may be affected, as differences in sugar and acid contents were observed.