Browsing by study line "Kasvintuotantotieteet"

The objectives of the study were to assess the efficiency of transient expression of sgRNA/Cas9 construct in Petunia V26, where sgRNA targeted a cytosine deaminase gene (CodA) that converts 5-fluorocytosine into the toxic compound 5-fluorouracil. Disrupting CodA by transient expression of sgRNA/Cas9 introduced a conditional negative selection system that allowed plants with mutated CodA to regenerate on media containing 5-fluorocytosine. The single transcriptional unit vector pMOH2 was designed to carry two amplified sgRNAs guiding Cas9 targeting at HinfI cutting sites. The expression vector was transformed into Petunia V26 using Agrobacterium tumefaciens (pGV2260). Successful mutations were detected on 62.5 mg/L 5-fluorocytosine. Large numbers of in vitro shoots were regenerated from the transformed leaves on a modified MS-media containing 1 mg/L zeatin. The study revealed that transient expression of the sgRNA/Cas9 construct is efficient and can be used to target other genes in Petunia V26. pMOH2 targeted its sites successfully, and proved that CodA can be used as a conditional negative selection marker to detect cells with an edited genome.

Anthropogenic activities have resulted in huge accumulation of plant nutrients in lake sediments. These nutrients can be recycled back to the overlying water and sustain eutrophication. The release of phosphorus (P) from sediments, i.e. internal P loading, has often been a reason for delay in improvement of lake water quality, after reduced external nutrient loading. By removing the sediment, the internal lake nutrient load can be effectively reduced, and it is widely used in lake water quality restoration. By redirecting the reclaimed nutrients back to primary agricultural production, the need for using mineral fertilizers and virgin materials can be reduced. Currently there is, however, a lack of field-scale experiments and determination of best practices to enable efficient nutrient uptake and minimized nutrient leaching back into the lakes. A field experiment was conducted to study the effects of using P-rich lake sediment in different application methods for growing a mixture of forage grasses. The study focused on soil fertility, plant growth and nutrition, and species composition over a period of four growing seasons in central Estonia. Treatments for reducing nutrient losses included applying the sediment alone (Sed), with surface-incorporated biochar (Sed+BC), and as incorporated with surface-mixed biochar-topsoil mixture (Sed+Soil+BC). A treatment consisting of sandy loam topsoil was set up as control (Soil). The mean dry mass yield in the sediment treatments exceeded the local average grass yields and the N and P uptake rates in above-ground biomass (AGB) exceeded the international estimates for grasses. The sediment had no significant effect on AGB yield in comparison to the control. Similarly, no effect was observed in the yield of weeds, but temporary changes in weed species composition and an increasing trend particularly in nettle abundance on the sediment treatments were recorded. Apart from a transient increase in the amount of soluble potassium, no relevant effects were induced by the incorporated biochar. In conclusion, the sediment performed well and served as a plentiful source of P for grasses for four years. Based on the sufficient concentrations of P, sulphur, calcium and potassium in the plant tissue, yield increase could have been expected but most likely the good fertility of the control topsoil evened out yield differences between growing medium treatments. Based on this study, similar lake sediments can be advised to be used as soil amendments on grass cultivation on an agricultural field. Due to high nutrient concentrations, a lower rate could be applied on a wider field area to control excess in nutrient supply, given that the need of nitrogen fertilization is ensured to match plant-specific requirements.

During the last 50 years, agriculture in Finland has become more intensive, open semi-natural farmland habitats have disappeared and the number of animals and plants has been declining. Nectar plants are beneficial resources in agroecosystems. They support crop pollinators, and natural enemies of pests and other species dependent on nectar. Nectar plants can also be indicators of biodiversity. Nectar source plants in field margins provide nectar (and pollen) over the growing season. Various plants benefit from different margins, and their frequency and distribution can be connected with the landscape structure and latitude. This study examined the distribution of nectar plants in field margins of farmland in Southern Finland and determined what plant species provide nectar and at what time of the season. The objectives of the research were to describe the species composition of nectar plant communities in Southern Finland, and hence the biodiversity of plants, and to study the distribution of nectar source plants in the most common margin types. The data were obtained from the Luonto-Mytvas Project research programme “Significance of the Finnish agri-environment support scheme for biodiversity and landscape (Nature MYTVAS)” in 2000-2006. In order to find out what plants have good nectar (pollen) availability literature sources and bee calendars were used. The results shows that the majority of 50 most frequent plants species included in the analysis have value as nectar and pollen sources available for pollinators. There were four different functional groups (f) of plants in the research, depending on their nectar availabilities. The frequent plants in the field margins are available as nectar/pollen sources to pollinators, from April until September-October. There are only few species dependent on margin type in their occurrence. Frequencies of most of the species from all the four groups varied, however, between field-to-field and field-to-road margins.

Nutrients get deposited in lake sediment from agricultural areas and other anthropogenic activities resulting in internal P loading and eutrophication. On the other hand, the situation with P rock (non renewable resource) used for production of mineral fertilizer is alarming that result in the depletion of P rock and increase P fertilizers price. The issue can be minimized by sediment removal and recycling nutrients from sediment for crop production. The existing results on sediment P availability for crops showed contradictory results and suggested that sediment P bioavailability for the crop is influenced by sediment iron to phosphorus mass ratio. However, comprehensive studies confirming their relationship are currently lacking. Hence, the study aims to determine the potential of sediment as fertilizers for crop (ryegrass) from several eutrophic lakes (in Finland and Estonia). The aim is to identify the effect of different lake sediments on ryegrass aboveground biomass and nutrient uptake. The study was conducted on greenhouse for around 6 months. Randomised complete block design was used for the experiment. The experimental treatments include sand with six different lake sediments: Peipsi, Lämmijärv, Kutajärvi, Kymijärvi, Matjärvi and Enonselkä basin of Vesijärvi, mineral fertilizer (positive) and without P fertilizer (negative) control. The biomass (yield) and nutrient uptake by the plants were measured and then analyzed for nutrient content. Significant effect of lake sediment was observed on ryegrass yield and P uptake. The significantly higher yield was observed for Lake Peipsi sediment treatment than in both controls. The ryegrass dry matter yield was greater in sediment treatments than negative control. Also, ryegrass yield was found to be greater in some sediment treatments than positive control. The concentration of nutrients (sulphur, calcium, magnesium, and potassium) was sufficient in ryegrass plant in all lake sediment treatments. The P uptake from Enonselkä sediment treatment was the highest whereas from Kutajärvi sediment treatment was the lowest. The P uptake was the highest (16.3 kg ha-1) in Enonselkä sediment treatment with the lowest Fe:P ratio of 12. Moreover, the result suggests that Fe:P mass ratio is one of the factors/sediment properties that determine P availability to the crops. However, other sediment properties may also affect P availability in the plants as organic P fraction was also used as an additional P source in some cases. The sediment increased C content and organic matter content compared to controls which improved ryegrass growth in sediment treatments. The increase in nutrient uptake and biomass in lake sediment treatments showed that lake sediment can be potential alternatives for fertilizers in nutrient deficient soil.

It is important to study the factors which inhibit the cultivation of major crops which serve as a source of food and feed, with various other medicinal values as well. One of these factors is soil degradation and infertility which could be due to high amounts of toxic elements or unfavourable pH conditions. Faba bean is one such crop and is widely affected by the acidity and aluminium toxicity in soil. In this study, an effort has been made to observe the varying tolerance of faba bean accessions and understand the underlying mechanisms used by them under stress conditions. The accessions selected were Aurora, Babylon and Kassa. Each accession was subjected to three treatments and were grown in pH 7 (control), pH 4.5 (acid treatment) and pH 4.5 + Al3+ (aluminium treatment). The pH of peat for acidic treatment was reduced to 4.5 using Sulphuric acid (H2SO4) and for aluminium treatment, Aluminium sulphate (Al2(SO4)3) was added in addition to the acid. At 16 Day after Sowing (DAS) and 30 DAS the physiological data was collected which comprised of chlorophyll concentration (SPAD value), stomatal conductance, leaf temperature and photosynthesis rate. At 35 DAS, the experiment terminated and the shoot data (fresh and dry weights of leaves and stem; and leaf area) of each plant was recorded. Then the root data (tap root length, quality and quantity of nodules and photographs of roots) was taken for each plant. ICP samples for peat, shoot and shoot were also analysed. The data collected were subjected to analysis of variance using R version 4.0.3. (means separated by 5% significance level). From the plant data, Aurora was found to be tolerant. Kassa was sensitive (especially the roots) and Babylon was sensitive to both acid and aluminium treatments. The ICP results provided the reason for this tolerance pattern and a higher concentration of elements needed for plant growth such as P and S were found to be higher in aluminium and acid treatments.

Late blight, caused by Phytophthora infestans (Mont.) de Bary, is considered the most devastating disease in potato (Solanum tuberosum L.) production worldwide. Control methods involve mostly the use of fungicides, which are costly and are under political pressure for reduction in Europe. Potatoes from the major potato cultivar in Sweden, King Edward, previously stacked with three resistance (R) genes (RB, Rpi-blb2 and Rpi-vnt1.1) were tested in a local Swedish field, with spontaneous P. infestans infection over three seasons to evaluate the effectiveness and stability of the resistance on leaves. In addition, testing of resistance was done in both in leaves and tubers. Field results demonstrated that the 3R stacked into the cultivar King Edward, showed practically full resistance to infections of P. infestans, with no difference to fungicide use. Moreover, the resistance was effective in both leaves and tubers. The results reveal the 3R potatoes offer a functional field resistance, that could, alone, reduce the total use of fungicides in agriculture by several percent in Sweden, in an event of modifications in the EU legislation.

Norway spruce is commonly cultivated throughout Europe, Russia, and Japan. Cultivation of Norway spruce often faces the issue of fungal diseases, one of which is cherry rust disease caused by Thekopsora areolata. The gene model MA_10g0010 encoding an uncharacterized peroxidase (PabPrx86) has previously been associated with the presence of this pathogen. The aim of this study was to describe and assay the protein produced from this gene model, observe its localization in the cell, and determine its relative expression level in different tissues of Norway spruce. Experiments were performed by isolating the full length cDNA for PabPrx86 and cloning the cDNA into destination vectors pEAQ-HT-DEST1 and pK7FWG2 leading to a hypertranslatable transcript and a C-terminal GFP fusion, respectively. The plasmid constructs were transformed to Agrobacterium tumefaciens and agro-infiltrated to Nicotiana benthamiana. In addition, the relative expression level of this gene in different spruce tissues at different times of the year was determined using the qRT-PCR method. Sequencing showed that there were two allelic variants of this gene in the spruce individual sampled for RNA. Results showed that both alleles code for a peroxidase with basic pI. Subcellular localization with the GFP tag detected that PabPrx86 protein was located out of cytoplasm, indicating that the protein was translated in the ER-ribosomes, whereas relative expression level analysis revealed that PabPrx86 was highest expressed in the bud and lateral bud in June. Peroxidases are known to relate with plant defense, but further experiments are required to determine the role of PabPrx86 in Norway spruce and what the association with T. areolata means.

Fragaria x ananassa is a widely appreciated berry with its production growing all around the world. Thus, there will be a huge demand for strawberry breeding in the future especially since the climate change is casting an extra shadow upon the growing conditions which is also why there is a need for better understanding of different cultivar types. There are everbearing and seasonally flowering cultivars of both Fragaria x ananassa and Fragaria vesca. The seasonally flowering types such as ʻHapilʼ flower once during the growing season whereas everbearing types such as ʻCalypsoʼ flower for a longer period. The gene behind the change in the flowering habit has been tracked to the photoperiodic pathway of F. vesca although the gene behind the trait in F x ananassa remains unknown. The aim of this project was to compare flowering and vegetative responses of in vitro propagated everbearing F x ananassa cultivar ʻCalypsoʼ and seasonally flowering ʻHapilʼ in long and short day photoperiodic conditions in order to find out differences between everbearing and seasonally flowering cultivars. This was done by collecting data from phenotype observations linked to the vegetative and generative stages of the development of strawberries. The phenotype data was then combined with gene expression data of FaSOC1, FaTFL1, FaGA20ox4 and FaAP1 which are genes known to work on the photoperiodic pathway that regulates the switch between the vegetative and generative development of both F x ananassa and F. vesca. In addition, the expression of an everbearing phenotype associated gene FaFT2 was analysed. This study was a part of a larger project aimed to find out the genetic basis for the everbearing habit of F x ananassa. Part of the ʻCalypsoʼ plants were induced to flower already during the acclimatization period and the rest at the very beginning of the treatment period which then caused differential flowering times between the ʻCalypsoʼ groups. Short day grown ʻHapilʼ was induced to flower between weeks three and six whereas long day grown ʻHapilsʼ remained vegetative. Phenotypic observations were also backed up by the expression of FaTFL1 and FaAP1. Instead the FaSOC1 expression was repressed in short day conditions more than in the long days regardless of the cultivar type. ‘Calypsos’ were capable of producing runners regardless of photoperiod or flower induction. Consequently the runner production seemed to be regulated by factors outside of the photoperiodic pathway. However, the expression of runnering associated FaGA20ox4 was low and variable due to the sampling strategy. Interestingly most of the axillary meristems of short day grown ‘Hapils’ remained dormant for an unknown reason. Expression of FaFT2 was low on the apical meristems and further support for the role of the gene in everbearing phenotype was not found.

Täsmäviljelyn yleistyminen on lisännyt tarvetta maaperän spatiaalisen vaihtelun kartoittamiselle, ja tämän myötä markkinoille on tullut erilaisia maaperäkartoitusmenetelmiä. Tämän tutkimuksen tavoitteena oli selvittää, pystytäänkö gammasäteilyn mittaamiseen perustuvalla SoilOptix-maaperäkartoitusmenetelmällä estimoida pellon sisäistä pH-arvon, helppoliukoisen fosforin sekä mangaanin vaihtelua. Tutkimus toteutettiin Forssassa sijaitsevalla peltolohkolla, jossa yhteensä 48 mittauspisteen maa-analyysituloksista ja SoilOptix-menetelmän pistemäisistä estimaateista tehtiin korrelaatioanalyysejä ja pistekaavioita. Myös gammasäteilyraakadatan toistettavuutta havainnoitiin visuaalisesti. Työn toinen tavoite oli selvittää, vähensikö peltolohkolle tehty täsmäkalkitus pellon sisäistä satovaihtelua ja ravinnevaihtelua. Tämän selvittämiseksi analysoitiin puimurin satokartoitusaineistoja vuoden 2020 kevätrapsin (Brassica napus ssp. oleifera (Moench) Metzg.) ja vuoden 2022 kevätvehnän (Triticum aestivum L.) puinneista. SoilOptix-menetelmällä ei pystytty estimoida peltolohkon sisäistä vaihtelua minkään koejäsenen osalta. Kalkitus ei oleellisesti vähentänyt peltolohkon sisäistä satovaihtelua, mutta ravinnevaihtelua se vähensi. Eri vuosien gammasäteilyn raakadatassa oli samankaltaisuuksia visuaaliseen havainnointiin pohjautuen. Syyt heikkojen korrelaatioiden taustalla eivät ole ilmeiset, ja ne vaatisivat lisätutkimusta. Erityinen kiinnostuksen kohde olisi menetelmässä kerätyn raakadatan lukuarvot, joita ei tässä tutkimuksessa saatu tarkastella. Johtopäätöksenä todetaan selvä lisätutkimuksen tarve menetelmälle.

Strawberry breeding in Finland began 60 years ago and has largely relied on traditional breeding methods. The geography of Finland, as well as local consumer preferences for darker-coloured strawberries, have been the main focus of selection in all implemented Finnish breeding programs. With several successful and popular cultivars have been released, the current focus is on increasing yield and disease resistance while maintaining the excellent fruit quality of breeders' selections. A panel of 175 garden strawberry accessions was created and trialled at the Natural Resources Institute Finland (Luke) as part of a Nordic-Baltic pre-breeding collaboration between the institute and the Norwegian breeding company Graminor AS. A medium-density, genome-wide scan for 50K SNPs has been performed on each individual of the panel. This panel represents the genetic diversity present and typical for cultivated strawberry in the Nordic-Baltic region, and it is expected to provide Nordic breeders with markers tailored to their plant material diversity, supporting their future selection decisions and accelerating their breeding cycles. In this study, symptom severities of two strawberry leaf diseases (leaf spot caused by Mycosphaerella fragariae and leaf scorch caused by Diplocarpon earlianum) and seven fruit quality traits (berry weight, skin colour, flesh colour, evenness of flesh colour, basket appearance, predominant berry shape and tip type) were scored in the panel. GAPIT and statgenGWAS statistical packages in R were used to run five different GWAS models: Significant SNP-trait associations were found using single-locus (GLM and MLM) and multi-locus (FarmCPU and BLINK) association mapping analyses. The study had shed a light on the importance of considering several statistical models and parameters for a maximum benefit of association mapping studies. Among significant SNP-trait associations for fruit weight, fruit skin colour and fruit flesh colour, four were partially characterized by inspecting their allelic effects. On chromosome Fvb6-1, appearance of consensus, significant signals from the flesh colour trait of secondary-position berries is discussed. Nine significant SNP-marker associations were detected for berry weight.