Browsing by department "Maataloustieteiden laitos"
Now showing items 21-40 of 415
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(2016)The aim of this master thesis was to evaluate suitability of a biogas plant as a manure maintenance method in a kind of a horse village, where many horse businesses are located close to each other. The suitability of the biogas plant was evaluated by ecological and economic effects. For ecological effects the investigation was made concerning nitrogen and phosphorus flows and for economic effects an evaluation was made concerning the total profitability of the biogas plant. Nitrogen and phosphorus flows were investigated by substance flow analysis. The evaluation was made by investigating internal flows, flows inside and outside of the system and the size of the flows of two systems in which one system was a horse village with a biogas plant and the other system was a horse village without a biogas plant. The horse village without the biogas plant was further divided into two options. One option was to spread the manure on fields and the other option was to hand over the manure. The economic profitability was evaluated by gross margin calculation concerning four different options which were a biogas plant producing CHP with and without financial support and a biogas plant producing fuel with and without financial support. Concerning nitrogen and phosphorus flows, the horse village where the manure is spread on fields is as good option as where the manure is being processed on a biogas plant and where the digested sludge is used for fertilizer as well. Handing over the manure outside the horse village is a worse option in relation to the local substances flow cycle. The construction of the biogas plant in horse village was profitable in every options. Although manure processed by biogas plant is evaluated to produce less nutrient loss compared to manure which is spread straight to the field, there still is a need for further investigation about the effects of biogas production on nutrient flows and nutrient losses in order to model the effects of a horse village. However, according to previous investigations it is known that biogas production decrease greenhouse gas effects. The profitability of biogas plant requires that manure maintenance costs of the horse village have been quite high before the biogas plant.
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(2013)The aim of this study was to look into the possibility of using predatory mites as a biological control agent in the nursery production. This study focuses on the biological control of two phytophagous mites, Tetranychus urticae and Aculus schlectendali that occur as pests in apple seedling production. The directive 2009/128/EY of the European Union obligates the farmers to follow the principles of the integrated pest management and favour other control methods, such as biological control, rather than chemical pesticides. This study is a part of The Finnish Nursery Producers Association’s project that aims to develop biological control practices for the nursery production in Finland and promote integrated pest management in nursery production. The experiments for this study were carried out outdoors in a field and indoors in a seasonal greenhouse, where the population development of T. urticae and A. schlechtendali on apple seedlings was followed. Population density of mites was counted from leaf samples gathered from the seedlings in two week intervals from May until the end of August. Biological control of T. urticae was tested with Phytoseeid mites, Neoseiulus barkeri and Phytoseiulus persimilis. Chemical control was used as a comparison treatment. The effects of the biological control were followed by comparing the population densities of phytophagous mites in the area of biological control to the mite densities in the area of chemical control. N. barkeri and P. persimilis were not able to prevent nor stop T. urticae population growth in the greenhouse where the densities of T. urticae grew higher in the area of biological control than in the area of chemical control. Outdoors the population densities of T. urticae remained low throughout the experiment in both treatment areas. Population densities of A. schlechtendali grew high indoors and outdoors within both treatments. Even though biological control did not succeed in these experiments, the conditions in the greenhouse were suitable for Phytoseeid mites and in theory it should be possible exploit them as control agents in nursery production. The high densities of A. schlechtendali were surprising. In the future it would be important to consider the importance of this species as a pest and find effective means to control it.
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(2018)Tiivistelmä/Referat – Abstract The long period of indoor feeding in Finland emphasizes the importance of good quality silage in dairy cow nutrition. Silage additives are used to ensure successful ensiling. Silage inoculants enhance silage lactic acid fermentation when lactic acid bacteria and sometimes enzymes and other fermentative bacteria are added to silage. Lactic acid content has been higher and pH lower in silages treated with inoculant than in silages without any additive. Aerobic stability of silage and total mixed ration (TMR) has been better with silage treated using inoculant compared to silage without additives. In some studies, the digestibility of dry matter and organic matter has been better with inoculant-treated silage. Silage dry matter intake has been improved with silage treated with inoculants in studies performed with dairy cows, growing beef cattle and sheep. Milk yield has increased in some studies with biological additive when compared to silage without additives. The aim of this study was to examine whether ensiling grass silage with biological additive influences feed intake or milk production of dairy cows in comparison to silage without inoculant. The study was conducted at the research farm of University of Helsinki. First cut timothy – meadow fescue sward was cut and wilted for 46 hours. The grass was harvested in round bales wrapped with 8 film layers either using silage inoculant (treatment B, with lactic acid bacteria and enzymes) or without additive (treatment A). A series of five bales of each silage were prepared one after another. The grass had dry matter of 183 g/kg before wilting and 328 g/kg after wilting. Water soluble carbohydrate concentration was 121 g/kg dry matter (DM). The silages were stored for 174 days before the beginning of the feeding trial. There were no differences in silage fermentation quality. Both silages had high concentration of lactic acid (100 g/kg DM). The dry matter contents were 296 and 294 g/kg and pH 4.25 and 4.31 for the inoculated silage and the silage without additive, respectively. Eight Finnish Ayrshire cows (95 days in milk, standard deviation 25.9) of second or later parity were used. The cows were kept in tie stalls during the trial. A double-reversal design was used with two treatments sequences (ABBA or BAAB) of 21 days each. The cows were fed with total mixed ration consisting of 65% (dry matter basis) of silage (inoculated or without additive), 20% of concentrate mixture, 13% rapeseed meal and 1.5% mineral supplement. Dry matter intake was 1,1 kg/d higher with the inoculated silage (p=0.01) than with untreated silage. Digestibility of dietary dry matter (p=0.02) and organic matter (p=0.02) was lower with inoculated than untreated silage. There was no difference in milk production between treatments (p=0.65). This study indicates that good fermentation quality of wilted (DM 300 g kg) grass silage can be achieved without additives. The increased dry matter intake or the lower digestibility of the diet containing inoculated silage cannot be explained by the silage composition or fermentation profile.
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(2011)In recent times climate change, decrease of fossil fuels and increase of their price have greatly increased worldwide interest in renewable energy sources. In Finland, there has been a lot of concentration towards forest industry’s secondary produced wood basis biomass, that forest industry uses for its energy production. Forest industry’s waste water cleaning process creates different kinds of sludge, which are either reused or destroyed by burning or transporting to waste treatment plant. Especially reuse of bio sludge is difficult, and waste area placing in the future is impossible or at least economically too expensive. In practice, sludge is treated by burning, and by drying it becomes a bio fuel. The energy use is the best way to destroy waste sludge. Because of the high water consist of the sludge it must be dried before burning. Drying the sludge with secondary energy flow with waste heat from forest industry processes increases energy income from the burning process and replaces the use of fossil fuels. The goal of this research was to find out the most optimal mixture of bark and sludge by changing different drying parameters. The experimental work was started by building a laboratory size fixed bed dryer for the energy technology experiment hall, where drying was studied by blowing heated air through the fuel layer. The dried fuel material was a mixture of bark and sludge, or just bark or sludge at different masses, different percentage mixtures and different temperatures. Making the drying curves was based on weight changes. In the test rig were probes for controlling and setting the temperature as the experiment expected. The temperature and weight changes were recorded to computer during the experiment. The drying experiments showed that sludge-bark mixture dries well, when the percentage of the sludge mass doesn’t increase over 50 %. When the share of sludge is higher, drying is no longer effective, which is due to channelling of the air through the dried fuel material in the fixed bed dryer. When drying the bark, increase of the temperature from 50 °C to 70 °C was much more effective than from 70 °C to 90 °C, the difference in drying time was about doubled.
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(2015)Brown-heart disorder in rutabaga is a boron deficiency syndrome that renders the inside of the roots brown and makes the crop unfit for market. The connection between boron deficiency and brown-heart was first reported in 1930’s. Brown-heart continues to be a concern for rutabaga growers all over the World, especially in Northern Europe, Canada, United States of America and New Zealand. The aim of this thesis was to compare the effects of various methods of applying boron, in terms of rutabaga yield and brown-heart. The field experiments were done in 2013 and 2014 on Räpi research farm of Apetit Ruoka Oyj in municipality of Köyliö, as part of collaboration between Apetit Ruoka Oyj and Yara Suomi Oyj. The companies aimed to find the best fertilizer solution for the prevention of brown-heart in rutabagas. Treatments were either fertilizer placement or broadcast application. In addition, foliar spraying treatment was used. Nutrient levels of the soil were analysed before planting and after harvest. The nutrient levels of rutabaga leaves before harvest, and nutrient levels of rutabaga roots by the time of harvest, were analysed. Additionally, the yield and number of rutabagas with brown-heart were determined. In experiments done in 2013, the effect of boron treatment on yield was statistically insignificant. In 2014, the fertilizer placement increased the yield as compared to broadcast application. In 2013 the number rutabagas with brown-heart disorder was significantly less within the samples treated with fertilizer placement, as compared to samples treated with broadcast applications. In 2014 the overall number of rutabagas with brown-heart was low, and the differences between treatments were statistically insignificant. Of the rutabaga boron treatments compared in this thesis, the fertilizer placement was more efficient than the broadcast application. Generally, the effect of foliar spraying treatment on yield or quality of the rutabagas was insignificant. In order to achieve high quality rutabaga crop, applying boron with fertilizer placement simultaneous to sowing, is recommended.
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(2017)Tämän maisterintutkielman tavoitteena oli selvittää eroja viiden kaupallisen broilerihybridin kävelykyvyssä ja aktiivisuudessa. Hypoteesina oli, että broilerihybridien väliset erot näkyvät kävelytestin ja muunnellun latency to lie- eli LTL-testin tuloksissa, videomateriaalissa ja tuotantotuloksissa. Kukkoja oli viittä kaupallista, yleisesti käytettyä broilerihybridiä, joista yksi oli hitaampikasvuinen, luomu- ja free range -tuotantoon käytetty hybridi. Sukupuolilajitellut 350 kukkoa (65-75 lintua/hybridi) jaettiin satunnaisesti 25 numeroituun karsinaan hybrideittäin (5 karsinaa/hybridi). Lintujen rehunkulutusta ja kasvua seurattiin koko kokeen ajan viikottain. Lintujen kävelykyky arvioitiin teuraspäivinä kävelytestillä ja muunnellulla LTL-testillä (koepäivät 15, 19, 22, 32, 36, 43 ja 49). Kaikille linnuille tehtiin ylimääräinen kävelytesti myös päivinä 27 ja 40. Lintujen käyttäytymistä videoitiin koepäivinä 12, 17, 25, 34 ja 41. Tarkkailtaviksi valittiin satunnaisesti kuusi värjättyä lintua per hybridi (yhteensä 30 lintua). Videoista analysoitiin jokaiselta päivältä kaksi 10 minuutin pituista jaksoa, joista kirjattiin ylös muutokset lintujen aktiivisuudessa (lintujen ryömintä- ja kävelysummat, seisoma- ja makuufrekvenssit ja kokonaismakuu- ja seisoma-aika). Lintujen tuotantotulosten ja kävelykyvyn väliset yhteydet testattiin Kendallin korrelaatiolla. Hybridillä oli erittäin merkitsevä vaikutus kävelykykyyn mitattuna kävelytestillä (p= 0,001). Hybridillä ei ollut merkitsevää vaikutusta lintujen muunnellun LTL-testin tuloksiin (p=0,394). Erittäin merkitsevä negatiivinen korrelaatio LTL-testitulokseen oli elopainolla (p=0,000) ja kävelytestin arvosanalla (p=0,000). Hybridillä oli erittäin merkitsevä vaikutus lintujen elopainoon (p=0,000). Hybridillä ei ollut merkitsevää vaikutusta lintujen videoista mitattuun aktiivisuuteen. Lintujen aktiivisuus korreloi negatiivisesti tarkkailupäivän ja kävelytestin arvosanan kanssa. Lintujen suurempi rintalihasten paino (p=0,001), elopaino (p=0,008) ja rintalihassaanto (p=0,008) huononsivat lintujen kävelytestin arvosanaa.
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(2014)Growing medium and its properties are an important factor affecting plant growth. One can improve the properties of growing medium with different amendments such as lime, nutrients and wetting agents depending on the requirements of the plant. The objective of this study was to examine a soil amendment called BRT EverGreen powder and its effect on white sphagnum peat and on plant growth. The powder has been created by a Finnish company Biomass Refine Technologies BRT ltd Oy. The powder is synthetically made of ureaformaldehyderesin and phosphoric acid includes added water retention lowering surfactants. In cultivation the goal by using BRT powder is to improve water retention and wetting of the growing medium and increase plant available nutrients. This study consisted of three experiments with three different plants or plant mixtures: Lactuca sativa L. ‘Grand Rapids’, Ligularia × hessei and a mixture of lawn (Festuca rubra L., Poa pratensis L. and Agrostis capillaris L.). These plants were expected to benefit from improved water retention of the growing medium. During the experiments the effect of BRT powder on the properties of white sphagnum peat and the speed, amount and quality of plant growth was measured. All plants got the same amount of water by irrigation. Mild nutrient solution was given to Lactuca and Ligularia with irrigation water three times during the experiments and no fertilizers were applied to the grass. The water retention ability of white sphagnum peat was not improved in plantless short term experiments by adding BRT powder. However the results given by direct moisture measurements from the growing medium implied that the BRT powder increased slightly the moisture content of the medium compared to pure peat. From the three different plant types tested only grass grew faster with BRT though the quality wasn’t as good as in pure peat. The improvement in growth was probably due to nutrients in BRT powder because no nutrients were applied to the grass unlike to Lactuca and Ligularia. There were no differences in the growth or quality of Lactuca. Ligularia did not grow as well with powder as in pure peat. Adding lime decreased the negative effect of BRT powder so the very low pH of the powder presumably hampered growth of Ligularia. BRT powder affects the growth of different plants in different ways. This makes its use in cultivation difficult because one does not know what the effect will be. The use of BRT is not recommendable in container cultivation with Lactuca or Ligularia when using peat. BRT powder can increase the growth of grass if additional fertilization is not applied.
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(2014)The aim of this study was to investigate the effects of graded amounts of camelina oil on milk fatty acid composition in lactating cows fed diets based on a mixture of grass and red clover silages. The experiment was carried out at the University of Helsinki research farm in Viikki 30th January 2009 – 23th April 2009. Eight multiparous Finnish Ayrshire cows participated in this experiment and four of them were rumen fistulated. Experimental design used was 4 x 4 Latin square. Treatments consisted of concentrate supplements containing various levels of camelina oil (0%, 2%, 4% and 6% on air-dry basis). All concentrates contained camelina expeller (20% on air-dry basis). The cows were offered daily 12 kg of experimental concentrate and silage ad libitum. The experimental periods lasted for 21 days. The first 14 days were adaptation period and the last 7 days formed sampling period. Increase of camelina oil level in the diet linearly decreased forage and whole diet dry matter intake (P?0,002). Camelina oil level did not affect organic matter, NDF and nitrogen whole-tract digestibility (P>0,10). Milk yield and milk protein- and lactose content linearly decreased when camelina oil level increased (P<0,001). Camelina oil level did not affect milk fat yield (P>0,100). Milk fat content (P=0,014) linearly increased and protein content (P=0,032) and urea content (P<0,001) linearly decreased when camelina oil level increased. Camelina oil level did not affect milk lactose content (P>0,100). Increase of camelina oil level linearly worsened milk taste panel scores (P=0,018). Camelina oil level did not affect plasma metabolite concentrations except that of total free fatty acids that linearly increased with camelina oil supplementation (P<0,001). Effects of camelina oil supplementation on rumen pH and rumen fermentation pattern were numerically negligible. Increase of camelina oil level linearly decreased the concentration of saturated fatty acids in milk fat (P<0,001) and linearly increased those of monounsaturated (P<0,001) and polyunsaturated (P<0,002) fatty acids. Increase of camelina oil level linearly decreased the content of mammary de novo synthesised short- and medium-chain 6-14-carbon fatty acid in milk fat (P?0,028). Camelina oil level had no effect on alphalinolenic acid content in milk fat (P>0.100). Increase of camelina oil level linearly increased trans fatty acids and CLA content in milk fat (P?0,008). Camelina oil supplementation did not affect neither the milk fat content of the final product of ruminal biohydrogenation of 18-carbon unsaturates stearic acid nor that of oleic acid (P>0,10). This is possibly due to biohydrogenation not proceeding to the end, ceasing to the last step before stearic acid. Milk fat trans-11 18:1 and cis-9, trans-11 CLA contents linearly increased at remarkably high levels when camelina oil level in the diet increased (P?0,008). This is possibly due to incomplete ruminal biohydrogenation of 18-carbon unsaturated fatty acids. Camelina oil supplement improved milk fat composition by decreasing saturated and increasing the trans-11 18:1 and cis-9,trans-11 CLA content in milk. However, giving camelina oil at high levels decreased silage and whole diet dry matter intake and affected milk production negatively.
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(2015)Porkkana on sekä tuotannollisesti että kotitalouksien kulutuksen kannalta merkittävin avomaanvihannes Suomessa. Porkkanan merkittävin tuholainen on porkkanakemppi (Trioza apicalis), jonka havaittiin vuonna 2009 toimivan myös porkkanaa infektoivan Candidatus Liberibacter solanacearum (CLs) -bakteerin levittäjänä. Merkittävimmät porkkananviljelyalueet sijaitsevat Lounais-Suomessa, joka on myös erityisen kemppiongelmaista aluetta. Alueella on havaittu myös runsaasti CLs-bakteerin aiheuttamaa voimakkaan punaista värittymisoiretta porkkanan lehdissä. Tämän tutkimuksen tavoitteena oli kartoittaa CLs-bakteeritaudin esiintyvyys Lounais-Suomen porkkanaviljelmillä ja määrittää CLs-positiivisten porkkanoiden osuudet eri oireryhmissä: oireettomat, kempinsyömät ja kempinsyömät värittymisoireiset. Tutkimuksen aikana pyrittiin kehittämään edullinen ja toimintavarma PCR-menetelmä CLs-bakteerin laajamittaiseen diagnostiikkaan soveltuvaksi. Lisäksi tutkimuksessa haluttiin tarkastella porkkanakemppien määrien vaihtelua lähekkäisillä porkkanapelloilla Kanta-Hämeessä. Tämän tutkielman CLs-kartoitus oli osa Maa -ja metsätalousministeriön rahoittamaa hanketta kartoittaa taudin levinneisyys Suomessa. Elintarviketurvallisuusviraston näytteeksi keräämät porkkanakasvit käsiteltiin Helsingin yliopiston kasvipatologian laboratoriossa, jossa näytteistä eristettiin DNA:ta ja tehtiin PCR-testit CLs-bakteerin toteamiseksi. Geelissä elektroforeesilla erotellut PCR-tuotteet kuvattiin UV-valossa ja CLs-positiiviset todennettiin vertaamalla PCR-tuotetta molekyylipainostandardiin ja positiiviseen kontrolliin. Toimintavarmimmaksi PCR-menetelmäksi osoittautui kuumassa lämpötilassa toimiva entsyymi ja lyhyt PCR-ohjelma. Kartoitustulokset osoittivat, että tautia esiintyy Lounais-Suomessa runsaasti, sillä suurin osa värittymisoireisista porkkanoista todettiin CLs-positiivisiksi. Sekä taudin että kemppien määrä osoittautui olevan Lounais-Suomessa suurempi kuin vertailualueilla Itä-Suomessa ja Pohjanmaalla. Kemppien määrissä läheisillä pelloilla havaittiin suurta vaihtelevuutta. Tällä hetkellä ainoa keino torjua CLs-bakteeritautia on keskittyä kemppien torjuntaan. Kemppipopulaatiot ovat kuitenkin tulleet viime vuosina kestävämmiksi yleisesti käytetyille torjunta-aineille, mikä luo uusia leviämismahdollisuuksia myös CLs-bakteerille.
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(2015)Efficient utilization of renewable plant and crop based biomass is one of the main areas of study in industrial biotechnology. Roughly 20-30 % of all plant biomass consists of hemicellulose, a polymer composed of six carbon (hexose) and five carbon (pentose) sugars. This proves a challenge in utilizing all available plant biomass efficiently, since many micro-organisms, which for instance readily ferment glucose (a hexose) into ethanol, will not do so for pentose sugars. Alternative pathways for utilization of pentose sugars are being looked for. Characterization of the Caulobacter crescentus D-xylonate dehydratase (Cc XyDHT) was the aim of this study. Cc XyDHT belongs to the ILVD/EDD protein family, whose members incorporate an iron-sulfur (FeS) cluster into their protein structure coordinated by two to four cysteine amino acids. Removal of the cysteine ligands should disrupt the incorporation of the FeS cluster, and thus presumably the activity of the enzyme. Three cysteines in Cc XyDHT which could act as ligands for the FeS cluster had previously been identified by sequence alignment among the ILVD/EDD family. Accordingly, four single cysteine-to-serine mutants of the Cc XyDHT as expression plasmid constructs were designed, with a non-conserved cysteine residue selected as a control. The wild type and mutated Cc XyDHTs were produced in Escherichia coli and purified with affinity chromatography using Strep-tag. SDS-page and Western blotting with an anti-Strep-tag antibody were used to confirm that the expressed proteins were Cc XyDHTs. The mutations’ effects on the protein fold and to the presence of the FeS cluster were investigated with UV and circular dichroism spectroscopy. Cc XyDHT catalyzes the conversion of D-xylonate into 2-keto-3-deoxy-xylonate. A colorimetric assay using thiobarbituric acid (TBA) as the reactant was used to measure enzymatic activity. The pH and temperature optima, substrate specificity, and enzyme kinetics of the wild type Cc XyDHT were determined. For the two best substrates, kcat/Km = 1220 mM/min for D-xylonate and kcat/Km = 1160 mM/min for D-gluconate were found. All three conserved mutations were found to reduce enzymatic activity more than 99 % with these substrates. Depending on which cysteine was disrupted, differences in the kinetic constants between D-xylonate and D-gluconate were found. The non-conserved mutation reduced activity by approx. 40 %. The spectroscopic results indicate that the three conserved mutants lacked the FeS cluster, while the non-conserved mutant still incorporated it. It can be concluded that the three conserved cysteines are involved in coordinating the FeS cluster, which itself plays an important role in the catalytic activity of Cc XyDHT. These findings should be helpful for follow-up studies in biotechnological application of pentose sugars acids and their derivatives.
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(2015)Yeasts have huge agricultural, medical and economic importance, and consequently, their isolation and identification are needed for more potential microbe resources. Studies of plant-microbe interaction have revealed many molecular mechanisms using mostly filamentous fungi, bacteria and viruses. However, our knowledge of yeast-plant interactions is lagging behind and there is a lack of yeasts known to interact with the model plant Arabidopsis. There were two major aims of this study: isolating and identifying the yeasts from wild growing Arabidopsis, as well as screening possible immunity modulation patterns of the strains against Arabidopsis. More than 70 yeast strains were isolated and identified belonging to 6 genera, suggesting the huge abundance of yeast diversity on plant surface. With the help of phylogenetic analysis of sequences from the internal transcription spacer (ITS) and D1/D2 region of 28S ribosomal DNA large subunit, one strain within the genus of Protomyces is proposed to be a novel species. Further carbon assimilation tests confirmed this, demonstrating differences of assimilation patterns between the new strain and all well described species in this genus. Another interesting finding was the possible pathogenicity of several yeast strains. Significant disease-like symptoms appeared on Arabidopsis five days after infiltration. Additionally, two strains synthesized auxin or related compounds in culture. Although more infections are necessary to confirm the pathogenicity, these have potential for development of new systems to study plant-yeast interactions with the genetic model plant Arabidopsis. The mechanism of yeast pathogenesis will provide new knowledge about plant defense and further assists plant breeding to produce crops with more durable resistance.
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(2015)The present work was based on the analysis of glyphosate concentrations in six soil layers after continuous multiple applications of herbicide products and various sampling times during the study period of 2010?2012, and aimed to contribute to a better recognition of the glyphosate persistence in clay soil. Two tillage methods (conventional tillage and no-till) were carried out in two replicates on the experimental field located in Jokioinen, South-Western Finland. This experiment was important for the identification of glyphosate amounts in soil profile and for planning a better field management in the future on the larger scale. Results of the study demonstrated that glyphosate and its metabolite AMPA remained on the field a year after the spraying of the herbicide. Calculated reference degradation rate constants and half-lives were proved to be in a range with literature review. While the impact of tillage methods on the glyphosate retention in soil was not possible to assess by the present study due to the quite sparse nature of the data, the residuals of glyphosate and AMPA at deep layers were almost non-detectable. Study clearly showed that accumulation of glyphosate happens mostly in topsoil, and the leaching potential into deeper layers was quite limited.
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(2016)Conifers are used for forest plantations and as landscape trees. Norway spruce is the main softwood species in Finland and can occasionally be observed in urban areas. However, root rots of conifer trees caused by Heterobasidion annosum leads to huge economic losses not only in Finland but also in other European countries. Due to the availability of complete genome sequence for both host and pathogen, in this study using Norway spruce and its root rot pathogen (Heterobasidion annosum) as an experimental model, the host-pathogen interaction was investigated. Conifer trees have established a variety of defense mechanisms to repel microbial infections, including constitutive barriers, accumulation of antimicrobial chemicals, activation of signaling pathways and induction of defense-related compounds resulted from an intra-organismic response including cell death. In the conifer pathosystem, cell death associated necrotic browning reactions promote tissue colonization by necrotrophic pathogens such as Heterobasidion annosum. By contrast, in crop plants, cell death associated hypersensitive response (HR) is known to inhibit invasive growth of biotrophic pathogens. However, not much is known about the chemical and molecular characteristics of necrotic cell death responses observed in different developmental stages of conifers from seedlings to mature trees. In addition, the term reaction zone is often used to describe responses of tree tissues bordering the heartwood to pathogenic infections, but nothing is known on whether there are any similarities between the necrosis response and reaction zone. To investigate this, Norway spruce at different developmental stages (seedlings, young trees and mature trees) were challenged with Heterobasidion parviporum. Six major indicators were assayed: necrosis lesions, cell death, pH, reaction zone, reactive oxygen species (ROS) and expressions of defense-related genes (Per1, Per2, LAC, JAZ1, OPR, and STS2). Increased transcript levels of the following genes Per1, Per2, LAC and JAZ1 were documented in seedlings but higher expression of Per2 and LAC was recorded in mature trees. Results revealed that all infected tissues were strongly necrotic or had increased lesion size. This is accompanied by increasing pH units up to 6.0 similar to levels documented in the reaction zone. Furthermore, ROS-generating peroxidase activity increased in infected tissues compared to the control. All these changes were found to be similar to observations in the reaction zone of woody trees. However, cell death was only measured in seedling roots and the method needs to be optimized for woody tissues. Further tests are therefore required for the clarification of relationship between necrotic cell death in seedling plants and reaction zone responses in mature woody tissues.
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(2010)Protein-energy malnutrition and mineral deficiencies are two of the three forms of nutritional deficiencies that affect most developing countries due to inadequate access to food and diets based on a sole crop. Common bean (Phaseolus vulgaris L.) is the staple crop of Nicaragua and it has the potential to improve the nutritional status of the poorest group of the nation. Its high content of both protein and nonhaem iron provides many nutrients, but inhibitors also may prevent absorption of iron and zinc by the human consumer. A proper production chain must be followed to ensure the best grain quality for the consumer. To achieve food security, both production and high nutritional content must be maintained. Four nationally important accessions of common bean, with different harvesting dates, were selected to be submitted to two treatments: to evaluate the impact of storage conditions on the end quality of the grain. The duration of the study was six months with sampling every six weeks, and the two treatments were controlled one stored at 40°C and 75 RH %, and the other was stored in in-situ conditions. Proximate and mineral composition was evaluated as well as tannin, phytate and bioavailability. Significant differences among different accessions were found, being the most significant in protein, Fe and Zn content, tannins and phytate. Protein values ranged from 21-23%. Iron content was 61-81 mg/kg but only 3-4% was bioavailable. Zinc content was 21-25 mg/kg and 10-12% was bioavailable. The concentration of phytate ranged from 8.6-9.6 mg/g while tannin values ranged within 37.7-43.8 mg/g. Storage at high temperatures was demonstrated to have an impact on certain nutritional compounds and proved detrimental to final grain quality. Soluble sugar content and tannin content decreased after six months in both storage conditions, IDF decreased in the in-situ and SDF in the stress. The iron content and bioavailability in INTA Biofortificado were not as outstanding as expected, so experiments should be conducted to compare its iron uptake and delivery with other cultivars.
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(2015)Need for higher productivity motivates and forces farmers to adapt new technological solutions. Global Navigation Satellite Systems (GNSS) have enabled several solutions to increase efficiency specially in field operations in terms of assisted or automatic steering, yield monitoring and precision farming. Accuracy of raw GNSS-data is poor and not suitable for any field operation. Methods to minimize error caused by different sources are in conclusive role to adapt positioning solutions to agriculture and to field operations. Aim of this study was to compare different GNSS correction methods by means of static and dynamic measurements. Results of the measurements occurred that high precision is achievable. Ground Based Augmentation Systems (GBAS) were more precise (RTK base station, AgriVRS and Centerpoint RTX) than Space Based Augmentation Systems (SBAS) (Omnistar G2 and Egnos). RMS values in 8 hour static measurements were between 0.004 and 0.406 m. Autonomic positioning RMS value was 1.014 m. In dynamic measurements scale was from 1.610 m to 0.015 m. Correction methods performed better in relative positioning than in repeating same position in subsequent days. Automatic steering is possible with every correction method. When using paid license corrections accuracy rises. Accuracy should be chosen by need of the field work, for example seeding needs higher accuracy than broadcasting of fertilizer. Due to Northern location of Finland SBAS are not available everywhere. Correction sent from satellite can be blocked for example by tree line. Also radio signal is hard to utilise in data transfer due to scattered field structure. Finland has excellent cellular network. Corrections loaded via cellular to receiver were available in test sites most practically.
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(2017)Leg weakness is one of the most common production diseases in pigs. Osteochondrosis is a joint disorder in which the endochondral ossification is disturbed. Leg weakness is mainly caused by osteochondrosis in pigs. Many factors like heredity and vitamin D status can affect the prevalence of osteochondrosis. This experiment was part of the international ProHealth project. The aim of this study was to investigate how two different vitamin D3 sources and feeding levels affect the prevalence of leg weakness in boars. Experiment design was 2 x 2 factorial. Commonly used vitamin D3 product (cholecalciferol) and Hy•D® product (25-hydroxycholecalciferol) were compared as vitamin D3 sources. Vitamin D3 feeding level 1 was in accordance of Finnish vitamin D3 recommendations and feeding level 2 was threefold with respect to the recommendations. Practical trial was carried out at Figen Oy’s research center in Längelmäki in 24.3. – 22.8.2016. Trial was conducted with 120 finishing boars. Average live weight of the boars at the end of the trial was 113 kg. Feed intake, daily weight gain, slaughter weight and bone strength were improved by greater feeding level of vitamin D3. Greater feeding level increased feed intake 6,13 kg of dry matter, slaughter weight 2,32 kg and bone strength 124,4 N during the trial. Daily weight gain increased 90,83 g/ d during the finishing period and 30,25 g/ d during the overall trial. Over 80 % of the pigs had excellent or good leg structure with only minor faults and their locomotion was fluent. There were no significant differences in leg structure or locomotion results between treatments. Pigs fed Hy•D® product with greater feeding level got double plasma 25-hydroxycholecalsiferol concentration when compared to pigs fed commonly used vitamin D3 product with greater feeding level. There were no significant treatment differences for 25-hydroxycholecalsiferol concentration in feeding level in accordance of the nutritional recommendations. There were no significant differences in plasma Ca, Pi or ALP concentrations between treatments either. Serious faults were observed more in distal humerus (elbow joint) compared to proximal humerus (shoulder joint) but there were no significant differences between treatments. In total of 11 pigs were removed from the treatments because of medical or tail biting reasons and in total of 50 pigs were medicated during the trial. Number of removed and medicated pigs divided evenly between treatments. According to this study the greater feeding level of vitamin D3 improved production. Feeding level of the vitamin D3 did not affect prevalence of the leg weakness or osteochondrosis. Source of the vitamin D3 did not affect production or prevalence of the leg weakness or osteochondrosis. Nutritional recommendations cover mainly the minimum need for nutrients and take no stand on optimizing production or health records. There is also some variation between research results. More research about the effects of vitamin D3 to prevalence of the leg weakness and the possibility to optimize production and health records with supplemental vitamin D3 is needed.
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(2017)DRama Queen (DRQ) is an unknown conserved gene that might be involved with sensing cytokinin signalling in the roots of Arabidopsis thaliana. It was originally found in a mutant screen when a mutated version of it – mDRQ – was found to improve the cytokinin sensitivity of plants in a desensitized genetic background. This thesis was done to define the protoxylem phenotype of mDRQ single mutant in Columbia (Col-0) background and to test the functionality of the gene by analyzing the complementation lines. The protoxylem phenotypes were scored from fuchsin stained samples by DIC microscopy. Protoxylem differentiation in the root of A. thaliana is an outcome of a mutually inhibitory signalling mechanism of auxins and cytokinins. Analysis of protoxylem status is a good tool for studying the cytokinin signalling because the differentiation is affected both by increased and reduced signalling levels. High signalling causes loss of protoxylem phenotypes whereas whereas low cytokinin signalling leads to ectopic protoxylem formation. The data of this thesis was analysed by SPSS version 22 software using cumulative logit modelling for the analysis. It was considered to be the most suitable alternative for analysis since the protoxylem phenotype data is ordinal by its nature. A protoxylem phenotype distribution was defined for mDRQ line and it was statistically different from Col-0. Most of the complementation lines were functional at a statistically significant level though the phenotype distributions of the complementation lines were not identical with original background. The difference could possibly be explained by the fact that the mDRQ gene is partially functional and may influence the phenotype distributions.
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(2017)High quality milk is an important thing for dairy industry and the most important determinator for milk price paid to the producer. The quality of milk is measured with somatic cell and bacteria count. Milks somatic cell count doesn’t change after milking that emphasizes the importance of udder health and successful milking. The total annual cost of the mastitis in an 100 head of cattle was estimated to be 21 000 – 25 000 euros in Finland (calculated with price level in 2010). Liner is the only part of the milking machine that contacts cow’s teat and the only way of bacteria into udder is through teat canal. Many bacterial infections occur in teat injuries and due to the teat-end roughness that makes teat canal closure slower, which makes bacteria access easier into udder. The aim of this thesis was to study the effects of CloverTM -liner on milking. Results were compared to the traditional HarmonyTM -liner. Cross section of a CloverTM -liner looks like clover whereas the shape of traditional liner cross section is round. Udder health and milking characteristics were measured attributes for comparison of the two liner models in this thesis. Udder health was evaluated by measuring somatic cell count, teat-end health and short-term changes in teat condition after milking. Milking characteristics were evaluated by measuring milk yield, milking duration and milk flow. The measurements were taken in two farms in summer 2015. The results of this study were estimated with line and bar charts as well as statistical significances were estimated with appropriate models. The differences between groups were small in teat-end health and there was a lot of deviation in the results so there were no statistically significant differences between groups. Total number of teats with short-term changes in teat condition after milking was so small that statistical testing was not appropriate. There were no differences in milk yield, milk flow, milking duration or somatic cell count between groups. The only statistically significant difference was peak flow that was lower for ClowerTM -liner.
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(2012)Sweetpotato is a subsistence crop for many thousands of families across the globe. The present studies in the thesis provide basic knowledge about Sweet potato chlorotic stunt virus (SPCSV) and Sweet potato feathery mottle virus (SPFMV) that were detected and characterized from sweetpotatoes in Guatemala and Honduras. Sweetpotato plants from Central American countries were showing typical virus-like symptoms. Different strategies were adopted for virus detection. SPCSV and SPFMV were found to be infecting sweetpotato plants. SPFMV was detected only in sweetpotato plants from Honduras. SPFMV infection was detected serologically and results were confirmed by RT-PCR and sequencing. A recently developed detection method, based on restrictotypes of PCR products by two different endonucleases, revealed co-infection of SPFMV strains C and RC in a sweetpotato plant from Honduras which was corroborated by sequencing 3'-proximal end (1.8 kb) of the genome and the coat protein (CP) ~940 nt based phylogenetic analysis. SPCSV was detected by double-stranded RNA extraction, confirmed by RT-PCR and subsequent sequencing of the partial HSP70h gene of genomic RNA2 gene of SPCSV. Phylogenetic analysis was done by constructing neighbour-joining tree of aligned nucleotide sequences, including SPCSV-EA isolates and SPCSV-WA isolates from database that clearly differentiated SPCSV isolates of Central American countries. These isolates from Guatemala and Honduras were grouped together with SPCSV-WA isolates from Argentina, United States, Spain, Israel, Nigeria and Egypt. Additionally, the RNase3 gene with UTR at 3´ end of genomic RNA1 gene of SPCSV was sequenced (1264 nt) and aligned against other WA isolates. It was found that the gene for the silencing suppressor protein p22 (676nt) was missing, reflecting intraspecific variation in the genomic structure of SPCSV. These findings revealed the two most important sweetpotato viruses in Guatemala, Honduras, and Central America for the first time and urge further studies of sweetpotato viruses in the region.
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(2010)Molecular biology has created a new pathway for plant breeding in cut flower industry. It focuses on studying flower gene functions and provides a more direct and effective way of breeding new flower cultivars using genetic transformation. Besides flower color, disease resistance, quality and vase life, modification of flower architecture is an important target for flower breeding. Previous studies have showed that various transcription factors encoded by the corresponding genes are involved regulating flower development and flower architecture. The most studied are MADS domain and TCP domain transcription factors. For targeted breeding, it is crucial to study the functions of the corresponding genes in detail. For both MADS and TCP domain proteins, previous studies have indicated that protein-protein interactions are important for their function. GhCYC1, GhCYC2, GhCYC3 and GhCYC4, isolated from gerbera (Gerbera hybrida), are CYCLOIDEA –like genes affecting inflorescence development. The protein-protein interactions among these four genes have previously been studied by yeast two-hybrid system. The aim of this thesis was to verify the interactions in living plant cells, using both BiFC and split luciferase assays. Protoplast electroporation and agroinfiltration were used to introduce the genes in planta. The results from the two assays were compared in order to find an effective in planta method for detecting protein-protein interactions. The experiment also provided information about DNA transformation efficiency using protoplast electroporation and agroinfiltration. The results of the split luciferase assay showed that GhCYC1+GhCYC4, GhCYC3+GhCYC4 as well as GhCYC4+GhCYC4 interacted quite strongly in plant cells while GhCYC1+GhCYC1, GhCYC2+GhCYC2 as well as GhCYC4+GhCYC2 had almost no interactions. The interactions between GhCYC3+GhCYC4, and GhCYC4+ GhCYC4 were also shown in yeast two-hybrid, but the other results were different. According to the BiFC assay, no signals of interactions were detected from GhCYC2+GhCYC2, while strong signals were observed from GhCYC2+GhCYC3, and weak signals were seen from GhCYC2+GhCYC4. The interactions between GhCYC2+GhCYC3, GhCYC2+GhCYC4 were also observed in yeast two-hybrid, but the other results were unconfirmed. Large standard deviations were observed in the split luciferase assay and thereby reliable conclusions cannot be drawn from it. However, BiFC turned out to be a better method to detect the protein-protein interactions in planta and clear signals from interactions could be observed. Comparison of the transformation methods indicated that agroinfiltration is a better way of introducing DNA into plant cells than protoplast electroporation. For further study, BiFC assay still needs to be repeated to confirm the efficiency of this assay, and factors affecting the transformation efficiency in protoplast electroporation need to be optimized in the future studies.
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