Browsing by discipline "Växtproduktionsvetenskap"

Pollen beetle is one of the most harmful pests of rapeseed and turnip rape in Europe. It can cause considerably high yield losses. In addition, due to routine use of pyrethroids, pyrethroid resistant strains of pollen beetle have developed in several European countries, including Finland. One alternative for pesticides is biological control, which can be enhanced by improving the survival of natural enemies of pests. In Finland two species of natural enemies of pollen beetle occur: Phradis morionellus and Diospilus capito. The aim of this study was to investigate long term changes in percent parasitism and test if certain factors have influence on it. The main data on percent parasitism was collected during 1985-1995 from different locations of the turnip rape cultivation area in Finland. To get some current data, percent parasitism was observed in 2015, though from smaller area than in the main data. In addition to data on total percent parasitism, specific data on both parasitoid species was available for most of the years. Also the density of pollen beetle larvae was observed during 1990-1995. Supplementary data was collected on soil types, growing zones, precipitation and average temperature and annual severity of aphid and pollen beetle attack. To test differences between geographical areas, the observed locations was divided into 18 minor areas, and further into six grand areas. Several statistical analyses were ran on such a diverse data. The results show that percent parasitism differed significantly between years, geographical areas and growing zones. Percent parasitism was significantly relative to temperature in May and rain in July, but no differences were found between related soil types. Percent parasitism was not relative to density of host larvae, but correlated negatively with host density in the following year. Strong negative correlation between both severity of aphid attack and annual sale of dimethoate indicates that the parasitoids are exposed to pesticides in those years with high annual abundance of aphids. From the two parasitoid species, P. morionellus occurred much more abundant than D. capito. As observed, percent parasitism can be very high, but in some years and geographically it can be diminished due to several factors. By decreasing harmful activities, parasitism could be enhanced and biological control of pollen beetle could be improved.

Kiinnostus rehumaissin (Zea mays L.) viljelyä kohtaan on kasvanut viimeisimpinä vuosina huomattavasti. Erityisesti maissin viljelystä ovat kiinnostuneet nautatilat, joilla maissirehu käytetäänkin usein rehuseoksessa yhtenä energiaa tuovana komponenttina. Oikea-aikaisesti korjatun maissirehun energia-arvo on korkea ja tämän vuoksi sadonkorjuun ajoittamisella on suuri vaikutus rehun laatuun. Tutkimuksen tavoitteena oli selvittää, miten sadonkorjuu tulisi ajoittaa, jotta maissirehu olisi parhaimmillaan paitsi sadon määrän kannalta myös laadullisesti. Tutkimus toteutettiin kenttäkokeena Helsingin yliopiston Viikin opetus- ja tutkimustilalla kasvukaudella 2017. Ensimmäinen sadonkorjuu pyrittiin ajoittamaan siten, että kuiva-ainepitoisuus olisi noin 20% ja sitä seuraavat kolme korjuukertaa aina noin 14 vuorokautta edellisistä sadonkorjuista. Korjuukerrat olivat 120, 134, 156 ja 176 vuorokautta kylvöstä. Sadonkorjuun yhteydessä korjattu tuoremassa punnittiin, tuore- ja kuiva-ainesatojen laskemista varten. Lisäksi yhden metrin pituudelta kerättiin kasvit, joiden lukumäärä laskettiin sekä määritettiin yksittäisen kasvin kokonaismassa ja pituus. Lisäksi tähkien määrä laskettiin ja niiden massa punnittiin. Tähkien ominaisuuksien avulla määritettiin tähkien kehitysvaihe. Korjuuajankohta ei vaikuttanut maissin tuore- ja kuiva-ainesadon määrään. Sen sijaan laatuominaisuuksista primaariseen kuiva-ainepitoisuuteen ja tärkkelyksen pitoisuuteen korjuuajankohta vaikutti. Muihin sadon laatuominaisuuksiin korjuuajankohta ei vaikuttanut. Tärkein havainto tutkimuksessa oli, että sadonkorjuu ajoitetaan tähkien R3 kehitysvaiheen jälkeen. Rehun laadun kannalta on kuitenkin parempi, jos korjuu tehdään vielä myöhemmissä tähkän kehitysvaiheissa, sillä sato on laadultaan parhaimmillaan vasta R5 vaiheessa. Tähkien R3 kehitysvaiheen jälkeen laatuominaisuudet, kuten primaarinen kuiva-aine-, tärkkelys- sekä NDF:n pitoisuudet nousivat tähkien edelleen kehittyessä. Vastaavasti sadon sulavuus, sokerin– ja raakavalkuaisen pitoisuus laskivat korjuun ajoittuessa myöhempään ajankohtaan kasvukaudella. Optimaalisimmaksi sadonkorjuun ajankohdaksi näiden tulosten perusteella voi suositella tähkien R5 -kehitysvaihetta, sillä tällöin rehun laatu on parhaimmillaan.

Alfalfa (Medicago sativa L.) has been cultivated all around the world since the ancient times. It has different cultivars having diverse characteristics that are suited for different environments and conditions. However, alfalfa is not being widely cultivated in northern latitudes, especially in the Nordic countries. In this experiment, six alfalfa cultivars from different origins, namely Alexis, Lavo, Live, Hunter River, Nexus and Rangelander were tested in four different treatments and control. The treatments simulated Finnish fall conditions, focusing on temperature and day-length. Plants were grown in controlled conditions with 12 h and 14 h day-length at 10°/5°C (day/night) and 18°/15°C (day/night) for six weeks. Control plants stayed in greenhouse conditions at 16 h day-length and 18°/14°C (day/night) until flowering. Both temperature and day-length affected plant growth and development. All cultivars flowered in the greenhouse conditions, characterized by the higher temperature and longest day-length. Cultivars Alexis, Hunter River and Rangelander developed flowers most rapidly (560 GDD), whereas Lavo, a cultivar bred for cold climates, flowered last (941 GDD). Only two cultivars, Hunter River and Alexis were able to flower at 14 h DL 18/15°C, while flower buds died at 14 h 10/5°C. Moreover, all flowers died under 12 h DL treatments both at 10/5°C and 18/15°C. The combination of short day-length and low temperature (12h DL 10/5°C) seems to delay or restrict the development to generative stage in Lavo, Nexus and Live. Cultivar Lavo seemed to have good fall dormant characteristics such as prostrate behavior, short stems, fewer internodes and a strong response to low temperature and short day-length. Although alfalfa is a long-day plant, it seems that temperature rather than day-length affected dry matter accumulation. Cultivar Lavo also responded more to low temperature conditions and started to accumulate more dry matter in roots. Global warming may increase the use of new crops such as alfalfa, in the Nordic countries. Alfalfa cultivars have interesting genetic variations that could be utilized for selecting most appropriate cultivars for growing in Finland.

From the beginning of 2013, the European Commission restricted the use of neonicotinoid based insecticides on honeybee attracting plants, such as Brassica oilseeds. This was done because neonicotinoids were believed to cause the death of honeybees. The initiative for this study came from the need to adapt to the change in insecticide use on oilseed crops. Adaptation had to happen at a time when the environmental effects of chemical control agents are evaluated from all sides. The aim of the study was to investigate if there was a correlation between seedling stage trichome abundance, or seed glucosinolate content, and flea beetle damage in Brassica rapa subsp. oleifera. The usability of trichomes and seed glucosinolates in increasing plant resistance against flea beetles was evaluated according to the results. The significance of seedling stage trichome density on the amount of flea beetle damage was investigated in field assays at Jokioinen 2015, and Loimaa 2016. Total glucosinolate content of different lines was determined from crushed seeds. Leaf trichome density, or seed total glucosinolate content, didn´t have a statistically significant effect on the formation of flea beetle damage. However, there is a multitude of scientific literature repeatedly suggesting that leaf trichomes can decrease flea beetle damage. This raises a question about the purposefulness of the methods used in exploring the phenomenon. Despite of this, the study revealed lines which suffered little beetle damage, because of an unknown reason. In the case of future research focus should be aimed at determining the resistance mechanisms in these lines. The role of glucosinolates, and their various hydrolysis products, as flea beetle repelling agents should be examined one compound at a time. This is because of their varied effects on flea beetle behaviour. Repelling substances are needed especially at the early seedling stage, because plants are most vulnerable to flea beetle damage at this growth stage. To maintain good nutritional and feed value, glucosinolates appearing in the seed should be avoided.

Alfalfa (Medicago sativa L.) is an interesting plant in grass mixtures because of its high yield and nitrogen fixing potential, and also high acceptance and forage value in animals. However, it is considered challenging to cultivate in Finland because of its high pH requirement and its poor ability to stand wet soil, trampling and cold winter. By ditching, liming and good management of field traffic it is possible to improve all these difficult growth conditions except for cold winter. The aim of this study was to investigate the differences in cold hardiness and the rate of cold hardening on six alfalfa cultivars having different origin and fall dormancy class. The aim was also to examine if the observed potential differences result from dry matter, starch and soluble sugar content in plant roots and shoots. Based on these traits, it was also intended to evaluate the suitability of tested cultivars for cultivation in Finland. The study composed of a field and a growth chamber experiment. In the field experiment the alfalfa cultivars ’Alexis’, ’Nexus’, ’Live’ and ’Lavo’ were tested, and in the growth chamber experiment also cultivars ’Hunter river’ and ’Rangelander’ were included. In the field experiment the samples were taken in total four times during winter 2014-2015. Sampling was done every other month starting from October. In the growth chamber experiment the plants were cold acclimated at two different programmes; 7/3 °C at day/night for three weeks and 7/3 °C for two weeks followed 5/-2 °C for one week. The cold hardiness of plants was determined by ion leakage test, in the field experiment from roots and in growth chamber experiment from roots and leaves. The dry matter content, soluble sugar content and starch content were also determined from roots and shoots in both experiments. The results showed that alfalfa plants tolerate well short cold temperatures. The 50 percent ion leakage, when plants are regarded to be dead, was not achieved with all cultivars, although the coldest freezing temperatures used in the artificial freezing test was -18 °C for the field and -16 °C in the growth chamber experiment. Freezing temperatures strengthened the hardening of plants in growth chamber trial and significant differences in cold tolerance were observed between cultivars. Hardening increased the soluble sugar content and decreased the starch content of plant roots in both experiments, but the differences between cultivars were not significant. Significant differences in sugar content of shoots were observed only between the cultivars with best and poorest freezing tolerance. According to the results of one-year field experiment all cultivars were suitable for cultivation in Finland.

Increasing crop yield is one of the objectives of plant breeding to turnip rape (Brassica rapa subsp. oleifera), which could be achieved with hybrid breeding method. Most promising method for turnip rape is the Ogu-INRA cms / Rf hybrid seed production method, which transferred from Japanese radish (Raphanus sativus) to rapeseed (Brassica napus subsp. oleifera). The hybrid breeding method for turnip rape still lacks a fertility restorer paternal line and solution has been sought through interspecific crosses between turnip rape and rapeseed. Turnip rape, rapeseed and radish contain similar regions in their genetic material, which allows the transfer of radish’s fertil-ity restoring PPR-gene region from rapeseed to turnip rape. The aim of this Master’s thesis was to develop an SNP-tool for the identification of R9 chromo-some regions and using SNP-tool to identify turnip rape F1 hybrid offsprings, which have fertility restoring PPR-B gene region, integrated from radish extra chromosome into the turnip rape ge-nome. Earlier in the project PPR-gene was located to the R9 chromosome with BAC64-clone, therefore work focused solely on identifying R9 chromosome regions. For the development of the SNP-tool, objective was to search for a database and select species-specific SNP-markers with in silico-method. B.rapa databases were selected for the work and SNP-markers species specificity tested in the laboratory. The developed SNP-tool consisted of species-specific 28 radish SNP-markers and 48 turnip rape SNP-markers. The results showed amplification of four radish SNP-markers in fertile indi-viduals of turnip rape offspring, which located closest to the PPR-B gene region that restores fertility on the R9 chromosome. However, the SNP-tool could not determine whether integration occurred in fertile individuals of F1 hybrid offsprings, or whether the fertility restoring PPR-B gene region was unintegrated radish chromosome, as all SNP-tools turnip rape SNP-markers am-plified in the turnip rape offsprings. The SNP tool cannot be utilized to develop turnip rape hybrid breeding method, because screening of integration would done to turnip rape F1 hybrids. In fertile individuals amplificated radish SNP-markers could be used as DNA selection markers to identify the individuals with the PPR-B gene region, that restores fertility in F1 hybrids. In addition, the SNP-tool revealed, that the excess of extra radish chromosome is not complete in the genome. This research is part of a research project of the development of a hybrid breeding method for turnip rape, which is studying the utilization of cross breeding between closely related plant spe-cies in the breeding to turnip rape in cooperation with Boreal Plant Breeding Ltd.

Globally growing meat consumption causes concerns as meat production contributes to a wide range of environmental impacts. Animal rearing emits considerable amount of greenhouse gases and may cause the eutrophication of water bodies. Animal production requires more inputs compared to crop production because of the low efficiency of feed conversion. In Finland, more than half of the agricultural area is used to produce feeds, which could also be consumed as human food. In this study, nitrogen (N) and phosphorus (P) flows were analyzed by substance flow analysis whereas agricultural land-use for different diets was analyzed based on current yield levels. The diets compared in this study were: the current average Finnish diet (BAU) and the vegan diet (VEG). VEG was determined by several diet recommendations for veganism. Land-use change by the diet scenarios was estimated by adjusting the production of crops that are grown in Finland. Nutrient flows were estimated based on the production of crops and domestic consumption by the diets. Only 31% of the current cultivated area for major cereals in Finland was needed for VEG. Only one fifth of nitrogen and one sixth of phosphorus uptake from soil to plant production in BAU was needed in VEG. Although 1.8 times more nitrogen and 1.5 times more phosphorus were needed from plant production in VEG compared to BAU, the final amount consumed from plant production by the domestic were larger in both nutrients. This study extremely narrowed the target system without considering import and export and the role of animal production in agriculture. These circumstances need to be considered in further research to understand better the impacts of animal production.

The leaves of healthy potato (Solanum tuberosum L.) plants and leaves systemically infected with Potato virus A (PVA; a monopartite positive sense single stranded RNA genome, genus: Potyvirus, family: Potyviridae) have been previously analysed and compared for the nuclear proteome to better understand the role of nucleus in plant virus infection. The analysis indicated that a small GTP-binding protein (ras-related protein; rabE1) is found in the nuclei of PVA-infected leaves but is absent from nuclei of healthy leaves. Therefore, to confirm the differential localization, this study was conducted. Subcellular localization of proteins was studied by tagging the protein with a marker protein, green fluorescent protein (GFP). The mRNA of ras-like protein, rabE1, of potato cv. Pentland Crown was cloned and expressed with GFP fused to the N- or C-terminus of rabE1 (GFP-ras and ras-GFP respectively). Plants of Nicotiana benthamiana were inoculated with PVA by two methods. Firstly, the Agrobacterium strains expressing GFP-ras or ras-GFP were mixed with the Agrobacterium strain expressing red fluorescent protein (RFP) or PVA-RFP and introduced to the healthy leaves of N. benthamiana plants and observed under epifluorescence microscope three days post inoculation. Secondly, PVA-RFP was agroinoculated to two or three basal leaves of young N. benthamiana plants and plants were grown for 12 days to allow systemic infection. Thereafter, PVA infected upper leaves and healthy leaves were infiltrated with GFP-ras or ras-GFP and the leaves were observed under epifluorescence microscope three days after infiltration. In healthy plants, GFP-ras localized to the cytoplasm and ras-GFP localized mostly to the cytoplasm and in few cells it was found both in the nucleus and cytoplasm. Whereas, in PVA infected cells, GFP-ras localized to the cytoplasm and in some cells to both nucleus and cytoplasm suggesting that PVA infection increases GFP-ras localization to the nucleus. However, no difference was observed in localization of ras-GFP in PVA infected and healthy leaves. The hypothesis of the research is thus partially true. Our study shows that rabE1 can be differentially localized in the healthy and PVA-infected plant cells.

The aim of this Thesis was to analyze Finnish food policy from a sustainability point of view. Changing operational environment, both globally and nationally, place food systems under a variety of economic, socio-cultural and ecological pressures. In addition to meet the basic objectives, such as ensuring food security, food systems are expected to fulfill a number of other goals. The drivers and goals, as well as means to food system change are defined in food policy. Considering the ecological, economic and sociocultural dimensions of sustainability in the food system analysis can also be viewed as an agroecological approach. A content analysis, using Atlas TI software was done for three most recent and topical Finnish food policy documents: Food2030 - government report on food policy, and the government programs for local and - organic food sectors. The food policy documents were analyzed with the following research questions in mind: how well is the need for systemic change recognized in the Finnish food policy; what are the main drivers for change; how are different dimensions of sustainability taken into account; is the change anticipated as gradual improvements to the current food system or are there any references suggesting radically reformed food system? The recently renewed Finnish food policy is specifically drafted with the current and forecasted changes in the operational environment in mind. The main drivers were mainly identified as sociocultural trends such as globalization, urbanization and changes in consumer behavior. The economic drivers, especially the competitiveness and export orientation of the food sector emerged as important goals for the future. The ecological dimension to food system reform gave the lowest share in all three categories (drivers, means and goals). A change in a complex system such as a food system takes place by affecting one partof the system at a time. The current Finnish food policy does not present radical changes or radical means to change the current system. However system-level changes can often be identified only afterwards.

Plant pathogenic fungi parasitize plants and cause invasive infection. With the development of next generation sequencing, a number of plant pathogenic fungi genomes are being sequenced and analyzed. The first completed genome sequence of Taphrina betulina, which is a biotrophic pathogen that causes striking twig clusters, known as witch's broom on birch, has been just finished. Genome sequencing yielded a 13 Mb assembly with 28 chromosomes. However, 10 of 28 chromosomes are considerably small. We hypothesized that these chromosomes may be dispensable chromosomes that are associated with pathogenicity. Essential gene distributions in identified Taphrina, Schizosaccharomyces species, and species identified with known dispensable chromosomes were compared. Evidence is presented that dispensable chromosomes are non-existent in T. betulina and this pipeline could find potential dispensable chromosomes. Furthermore, discontinuous essential gene distribution promotes our second hypothesis that T. betulina has some features of a “two-speed genome”. “Two-speed genome” consists of gene-dense regions and gene- sparse regions. Genes located in gene-sparse regions tend to evolve faster than the rest. Gene ontology (GO) describes the functionality of a gene and its products from three domains: cellular components, molecular functions and biological process. GO enrichment analyses of “slow-speed region” and “fast- speed region” genes were compared, facilitating the finding of candidate virulence effectors.