Patogeensed ja arbuskulaarmükoriissed seened Eesti kartulipõldudel

A Thesis for applying for the degree of Doctor of Philosophy in Agricultural Sciences.Soil fungi have fundamental ecological roles as decomposers, mutualists, and pathogens of plants. Roots of agricultural plants are hosts for various microorganisms. These include many harmful, often soilborne, pathogens, as well as beneficial organisms such as plant growth- and health‐promoting arbuscular mycorrhizal (AM) fungi. Potato (Solanum tuberosum L.) yield and quality is very sensitive to various pathogens. Soils contain distinct AM fungal communities and most crops (including potato) naturally become colonized by AM fungi in the absence of inoculation. In the current thesis, diversity, abundance, and community composition of putative pathogenic fungi and symbiotic AM fungi in potato fields in Estonia is studied. We found that potato roots have higher AM fungal colonization levels under organic, rather than conventional, farming. However, colonization of potato roots by AM fungi is extremely low in both of these management types. Relative abundance of AM fungi is significantly higher at the end of the growing season compared to the beginning. Seasonal and cultivar-driven changes of soilborne phytopathogenic fungal communities in conventional potato production, both within roots and in soil, were studied for the first time on a large number of potato cultivars using high-throughput sequencing. Cultivar influenced root-pathogenic fungal richness and community composition more than sampling time or sampling time x cultivar interaction. Additionally, cultivar had a significant effect on root fungal pathogen relative abundance. In soil, the community composition of putative pathogenic fungi changed significantly over time. Under increasing threat of plant disease outbreaks, the speed of detection of plant disease agents is essential for avoiding large-scale crop losses. This thesis work demonstrated that the third-generation sequencing device MinION is well suited for rapid, PCR-free diagnosis of fungal pathogens and other eukaryotic organisms. However, care should be taken due to a number of possible limitations that might lead to misdiagnosis. Our findings demonstrate that AM fungi are present in Estonian conventional potato fields, but studied potato cultivars exhibit low AM root colonization levels. In order to benefit from AM fungi in potato cultivation, a potato growing technique that involves less soil disturbance could be used. The results of this thesis work also indicate the importance of plant breeding, concerning disease resistance; and offer implications for rapid pathogen diagnostics that may help to avoid large-scale crop losses caused by new, emerging pathogens that are undetectable from symptoms.Muld on elupaigaks miljonitele mikroorganismidele, sealhulgas nii taimekasvu kahjustavatele kui ka soodustavatele seentele. Kartuli (Solanum tuberosum L.) saagikust ja kvaliteeti ohustavad mitmed seenpatogeenid. Teisalt on kartul võimeline moodustama kasulike krohmseentega arbuskulaarset mükoriisat (AM). Käesolevas doktoritöös analüüsiti Eesti traditsioonilise kasvatustehnoloogiaga kartulipõldudel kartulijuuri ja mulda asustavate patogeensete seente ja taimedega sümbioosis kasvavate arbuskulaarmükoriissete seente mitmekesisuse näitajaid ning nende seoseid kartuli kasvufaasi ja sordiga. Lisaks katsetati ülikiireid protokolle taimekoest patogeenide tuvastamiseks. Käesoleva doktoritöö tulemused näitasid, et AM-seente kolonisatsioon oli üldiselt väga väike, kuid maheviljeluses oli see siiski suurem kui tavaviljeluses. Kartuli kasvuperioodi lõpus on põllumulla AM seente suhteline ohtrus võrreldes kasvuperioodi algusega oluliselt kõrgem. Selle põhjuseks võib olla kasvuperioodi alguses läbiviidavate mitmete järjestikuste mullaharimise häiringu võimalik mõju, mis aeglustab mullas looduslikult eksisteerivate AM seente ja lühikese kasvuajaga kartulitaime vahel sümbioosi tekkimist. Sekveneerimisel tuvastatud patogeensete seente suhteline ohtrus juurtes ja mullas sõltus nii taime kasvufaasist kui ka kartulisordist. Kui juurte patogeensete seente liigirikkust ja liigilist koosseisu mõjutas kartulisort, siis mulla patogeensete seeneliikide koosseisu mõjutas taime kasvufaas. Seega lubavad antud töö tulemused järeldada, et taimesortide geneetiline mitmekesisus põllul võib aidata luua põllukultuure ohustavatele patogeenidele vähem soodsa keskkonna ja seeläbi aidata luua jätkusuutlikuma agroökosüsteemi. Antud töö tulemusena leiti teadusele uudsena, et taskusekvenaatorit MinION-i saab kasutada taimekoes domineerivate patogeenide kiireks ja täpseks PCR-vabaks diagnoosimiseks. Siiski tuleb olla ettevaatlik mitmete võimalike analüüsimisel ette tulevate kõrvalekallete suhtes. Uuringute tulemused on kartulikasvatuses suure praktilise väärtusega ning kinnitavad, et krohmseened on kartulipõldudel olemas, kuid tänapäevased sordid ja kasvatustehnoloogiad ei soodusta AM seenekolonisatsiooni moodustumist. Töö tulemustest järeldub, et säästlikus kartulikasvatuses tuleb panustada rohkem sortide resistentsusaretusele ning juba aretusprogrammides võtta arvesse taim-mikroorganism vastastikuseid toimeid ja mõjusid. Antud uurimistöö tulemusena on võimalik parandada patogeenide kiiret diagnostikat, mis omakorda aitab kaasa taimepatogeenidest tingitud ulatuslike saagikadude vähendamisele.Publication of this thesis is supported by the Estonian University of Life Sciences and the European Union’s European Regional Development Fund (Estonian University of Life Sciences ASTRA project “Value-chain based bio-economy”)

Feedback and Feedforward as a Dialogic Communication in the Learning Environment

Feedback concept in education is broad and covers several functionalities. The aim of this essay is to open up feedback and feed-forward concept as a process of dialogic communication both on individual level and in (educational) organization. While feedback provides information retrospectively (how has it been?), feed-forward would guide the future progress. While approaching the feedback from the point of view of dialogic communication, this study proposes different aspects of the feedback addressee and feedback provider could negotiate in order to make the feedback satisfying for both sides: number of aspects, time, generalization, and—whose task is to “interpret” feedback to feed-forward. The essay opens up the complexity of feedback and feed-forward asking/giving/receiving from the point of view of interpersonal as well as organizational communication. While approaching feedback giving and receiving as interpersonal communication it might include “noise”—unintended and sometimes spontaneous messages. The essay includes illustrative examples from the daily communication practice concerning the complexity of giving analytical descriptive feedback. On organizational level, the essay suggests to consider carefully the purpose of the feedback, the data collection methods and how the organization can make use of the data

Cost effectiveness of journalism education in a small nation state

The article discusses the role of journalism as a discipline in a small nation state and provides analysis of the economic factors that influence the journalism programs. The article discusses some of the economic aspects of journalism education at the academic university and provides a case study on the basis of the two programs provided by the University of Tartu: Bachelor (BA) and Master’s (MA) programs. The curricula are held by the Institute of Journalism and Communication. Keywords: journalism curriculum, education, cost, small market. p

Assessment and testing of strawberry pathogens

Success story of the Euphresco project 'Assessment and testing of strawberry pathogens

Mapping Digital Media: Estonia

The Mapping Digital Media project examines the global opportunities and risks created by the transition from traditional to digital media. Covering 60 countries, the project examines how these changes affect the core democratic service that any media system should provide: news about political, economic, and social affairs.Estonia blazed a trail, in terms of digitization, by completing digital switch-over of television in 2010, five years ahead of the originally envisaged target of 2015.Estonians have demonstrated a keen appetite for digital media uptake. More than three-quarters of the population accesses the internet regularly, and more than half of those are active on social networking platforms. Recent surveys suggest that nearly a quarter of internet users now connect via smartphones. As for traditional media, newspaper circulations have experienced a steady rather than dramatic decline over recent years, while television and radio audiences remain relatively stable.The press and news organizations remain in general relatively free of political influence, and although there is significant cross-media ownership and little opportunity for new entrants, digitization does not appear to have exacerbated this situation, and there remains a degree of competition and pluralism within all sectors.This report calls for the development of media policy that will incentivize television service providers to introduce the additional digital television services that were promoted during switch-over. They also call for long-term predictable funding mechanisms to ensure that public service media, Estonian Public Broadcasting (Eesti Rahvusringhääling, ERR) above all, provide quality output

The Curving Mirror of Time

This volume attempts to create a ‘relief map’ of temporalities in Estonian newspapers over different periods of time. The special focus is on binding the empirical analysis to the theoretical and methodological discussions of the temporality of news(paper) culture. The authors of the articles ask to what extent newspapers report on the past and present and to what extent these reports refer to the future. A diachronic analysis of newspaper texts from different periods of time demonstrates that the temporal focus of newspapers changes over time: in some periods, the past receives remarkably more attention, while in other periods the news timeframe is biased towards current events and the future. One study asks how similar, or different, is the (re)construction of the past in Estonian daily newspapers published in Estonian and Russian in 1994 and 2009. Two articles focus on analysis of the links between social remembering and anniversary journalism. Another article provides an overview of the depiction of women in Estonian newspapers and magazines from 1848 to 1940. This collection revitalizes the study of time in news discourse, suggesting new methodological perspectives and developing interdisciplinary approaches in cultural theory

Kopsu hiiglaslik ehhinokokiline tsüst

Ehhinokokoos (echinococcosis) on tänapäevani oluline tervishoiuprobleem. Haigus esineb endeemiliselt arenenud loomakasvatuspiirkondades kogu maailmas ja seda põhjustab parasiit Echinococcus granulosus, Echinococcus vogeli või Echinococcus multilocularis. Ehhinokokoosi korral tekivad elundites ühe- või mitmekambrilised põistangud ehk tsüstid. Kõige sagedamini paiknevad tsüstid maksas ja/või kopsus. Tsüstid suurenevad pikkamööda ja võivad saavutada 15–20 cm läbimõõdu. Haigus progresseerub väga aeglaselt ja selle diagnoosimine on keeruline. Parimaks on osutunud kirurgiline ravi. Eesti Arst 2004; 83 (12): 839–84

Is Estonian barley ready to tackle climate change-induced water regimes?

Saabunud / Received 25.09.2021 ; Aktsepteeritud / Accepted 27.10.2021 ; Avaldatud veebis / Published online 27.10.2021 ; Vastutav autor / Corresponding author: Siim Samuel Sepp [email protected] objective was to examine the effect of drought and flood on barley plants' biomass and growth rate in early vegetative development while comparing the stress adaption of different varieties. A greenhouse trial was conducted in the Estonian Crop Research Institute (ECRI) in 2021, where five Estonian grown spring barley varieties were grown in optimal, drought and flood treatments for six weeks to measure plants' projected leaf area (PA) and relative growth rate (RGR) through phenotyping. Both drought and flooding stress have a strong negative impact on plant biomass in early vegetative growth phases, causing PA at the end of the trial to decrease 26% and 49% respectively. Meanwhile, RGR throughout the trial decreased 6% in drought treatment and 16% in flood treatment. This indicates the greater impact of flood stress on plant's growth compared to drought stress. Genetic variation related to adaption to extreme water regimes in varieties is rather low, especially in drought stress conditions. In drought treatment, the variation coefficient (CV) was 14%, and in flood treatment 25%. Even as most varieties' PA and RGR varied between treatments, the difference between varieties in specific stress treatments was minimal. Estonian grown spring barley varieties are susceptible to extreme water regime related stress caused by potential climate change. This indicates the importance of assessing water-related stress tolerance in breeding material, adapting more accurate innovative evaluation approaches, and integrating climate-resilient genetic material into breeding programs, to hedge the risk caused by unfavourable growth environments in Estonian barley production