Erikoidse mükoriisa ökoloogia

Väitekirja elektrooniline versioon ei sisalda publikatsiooneSümbioos mükoriisa ehk seenjuure vahendusel on üks vanimaid ja enim levinud mutualismivorme maailmas. Mükoriissetes suhetes seenpartner varustab taime vees lahustunud mineraalainetega ning saab taimelt vastu suhkruid. Erikoidne mükoriisa (ErM) on arbuskulaarse mükoriisa ja ektomükoriisa kõrval evolutsiooniliselt noorim mükoriisatüüp. Taimed sugukonnast kanarbikulised (Ericaceae), kuhu kuuluvad ka mustikas, pohl ja kanarbik, moodustavad ErM sümbioosi mitmete rühmade mullas ja juurtes elavate endofüütsete seentega. Seenehüüfid kasvavad taime juurerakkudesse sisse ja moodustavad paunakesi – ajukujulisi struktuure, kus taime rakumembraani ja seeneraku piirpind on oluliselt suurenenud toitaainete vahetuse soodustamiseks. Kanarbikulised esinevad sageli vaestel happelistel muldadel, kus toitained on peamiselt orgaanilisel kujul ja raskesti taimedele omastatavad. Kanarbikuliste peamine ökoloogiline kohastumus ongi mükoriisaseente abil makro- ja mikroelementide kättesaamine. Kanarbikulised on metsanduse ja põllumajanduse aspektist väheolulised, mistõttu ErM ökofüsioloogia ja sellega seotud seente elurikkust on vähe uuritud võrreldes teiste mükoriisatüüpidega. Senised elurikkuse uuringud ja mükoriisa sünteesi katse näitavad, et ErM moodustavad seened kuuluvad mitmesse kottseente (Helotiales, Chaetothyriales) ja kandseente (Sebacinales, Hymenochaetales) seltsidesse. Oma väitekirjas keskendun erinevatele aspektidele ErM seente elurikkuses ja ökoloogias, eelkõige keskkonnaparameetritele, mis mõjutavad seenekooslusi. ErM seente tuvastamiseks isoleerisin kanarbikuliste ja hariliku kuuse juurtes kasvavad seened puhaskultuuri Tsehhimaa ja Norra metsadest ning viisin läbi mükoriisa sünteesi katsed laboris. Välitööde käigus kogusime kanarbikuliste juuri Mount Wilhelmi mäelt Paapua Uus-Guineas ja Drakensbergi mägedest Lõuna-Aafrika Vabariigis. Kasutasin Roche 454 pürosekveneerimise tehnoloogiat sealt kogutud juurtelt seente määramiseks. Leidsin, et senimääramata kandseente haru moodustab erikoidset mükoriisat, kus taimerakkude pinnal areneb õhuke seeneniidistiku kiht ja seen soodustab mustika kasvu ning lagundab aromaatseid polümeere. Kuusejuurtelt isoleeritud kottseened Pezoloma ericae liigikompleksist on võimelised moodustama erikoidsele mükoriisale iseloomulikke struktuure mustika juurerakkudes. Kottseeneliik Acephala macrosclerotiorum moodustab ektomükoriisat hariliku kuusega ja erikoidset mükoriisat mustikaga laboritingimustes. Kanarbikuliste seenekooslusi mõjutavad paljud keskkonnaparameetrid, eelkõige kõrgus üle merepinna, peremeestaime liik ning mikroelupaik niiskuse gradiendil. Erikoidset mükoriisat moodustavad seened erinevad tugevasti oma leviku poolest.Vast majority of plants live in mutually beneficial partnership with soil fungi. This partnership is called mycorrhizal symbiosis, which plays a crucial role in plant nutrient uptake. Plants feed symbiotic fungi with energy-rich compounds, such as sugars. Mycorrhizal symbiosis is one of the oldest and the most widespread symbioses on the Earth. Several types of mycorrhizal symbiosis have evolved during almost 500 million years. One of the youngest mycorrhizal type is ericoid mycorrhizal (ErM) symbiosis, a mutualistic relationship formed between plants from the Ericaceae family (so-called ericoid mycorrhizal plants; e.g. blueberry, rhododendron, heather) and diverse group of soil fungi (so-called ericoid mycorrhizal fungi). Ericoid mycorrhizal plants often occur in very harsh environments on extremely poor soils, where most of the nutrients are not directly available for plants, because these are locked up in complex forms of soil organic matter. The ErM symbiosis represents a key evolutionary adaptation of ErM plants to take up the nutrients from such substrates and survive in unfavorable conditions. In spite of the importance of ErM for the plants and fungi as well as for functioning of the ecosystems, ErM remains largely overlooked compared to the more common mycorrhizal types, such as arbuscular mycorrhiza and ectomycorrhizal; and a broader general understanding of the ErM symbiosis is therefore lacking. In this thesis, I focus on Ericaceae-associated fungi from various aspects of the partnership. Firstly, this thesis aims to determine the occurrence of ericoid mycorrhizal life-style among fungi. Furthermore, the thesis also focused on determination of environmental factors which significantly affect composition of fungal communities associated with roots of ErM plants. I found a novel lineage of fungi from the Basidiomycota phylum, which formed characteristic sheathed ErM symbiosis and enhanced growth of blueberry in vitro. This mycobiont showed even better ability to degrade a highly recalcitrant substrate compare to previsouly determined ErM fungi. In addition, I found that the communities of Ericaceae root-associated fungi were affected by environmental factors such as elevation and host plant species on a local spatial scale. On the global scale I found that some ErM fungal species have a very broad distribution range, while other species have much narrower distribution range restricted to a single hemisphere or continent

CRITICAL SHIFTING WINDOW IN SWITCHABLE ROCKER FINGER FOLLOWER

A valvetrain including switchable rocker finger follower is capable of discrete switching between two modes (two cam profiles). The exact moment when switching occurs is called crossover point and this paper reviews the factors that cause the shift of the crossover point from its nominal design position. The range where crossover point can shift is called critical shifting window and its size and factors influencing it will be adressed

LaTeX DTP System Video Tutorials for Beginners

Cílem této bakalářské práce je vytvořit soubor videotutoriálů pro práci s typografickým systémem LaTeX a porovnání jeho jednotlivých variant a editorů. Porovnávat se budou tři systémy: LaTeX, ConTeXt a LuaTeX. Tato práce se také bude zabývat srovnáním vybraných LaTeX editorů. Kromě teoretických popisů bude výsledkem této práce soubor videotutoriálů, které začátečníkovi pomohou se sazbou dokumentů.The aim of this thesis is to create a set of video tutorials for using the typesetting system LaTeX and comparison of its individual extensions and editors. The comparison will include three variants: LaTeX, ConTeXt and LuaTeX. This thesis will also deal with comparison of selected LaTeX editors. Apart from teoretical descriptions the result of this thesis will be set of video tutorials, which will help beginners with document typesetting.440 - Katedra telekomunikační technikyvýborn

Výskyt a význam hub asociovaných s kořeny mykotrofních rostlin

Mycorrhizal symbiosis represents one of the most important symbioses in the plant kingdom. It is a mutualistic interaction between plant roots and filamentous fungi, where fungal partner provides mineral nutrients, water and often improved protection against pathogens and plants supply fungi with photosynthetic assimilates. Besides mycorrhizal fungi, plants interact with a miscellaneous group of non-mycorrhizal root associated fungi, so called fungal endophytes. Notwithstanding ubiquity and possible importance of root associated fungi, their interactions with host plants have not been hitherto satisfactorily studied. The present Master thesis contains three papers and is aimed on two interesting topics contributing to unveiling different roles of mycorrhizal symbioses in ecological significance of plants and their survival and fitness in specific environments: (i) to address the potential role of ectomycorrhizal fungi and Ericaceae plants in facilitating the invasion of Pinus strobus and (ii) to identify mycorrhizal and non-mycorrhizal fungi associated with endangered orchid and aquatic plants. We assessed diversity and communities' composition of mycorrhizal and non- mycorrhizal fungi using classical culture-dependent approaches as well as modern culture- independent techniques. Results from the first...Mykorhizní symbióza představuje jednu z nejdůležitějších interakcí v rostlinné říši. Jedná se o mutualistickou interakci mezi kořeny rostlin a vláknitými houbami, kde mykobiont poskytuje rostlině minerální živiny a vodu, či ji chrání proti patogenům a na druhou stranu rostlina houbě poskytuje část svých asimilátů. Kromě hub mykorhizních hostí rostliny ve svém kořenovém systému i velmi početnou skupinu nemykorhizních hub neboli endofytů. I přes všudypřítomnost endofytických hub a jejich možný význam pro hostitelskou rostlinu jim nebyla doposud věnována dostatečná pozornost. Předkládaná magisterská práce je založena na třech článcích a klade si za cíl přispět k celkovému pochopení významu mykorhizních a nemykorhizních interakcí v ekofyziologii rostlin a fungování ekosystémů; a to zodpovězením otázek týkajících se dvou hlavních tématických okruhů: (i) potenciální význam a role ektomykorhizních hub a vřesovcovitých rostlin během invaze borovice vejmutovky a (ii) druhové složení mykorhizních a nemykorhizních hub asociovaných s kořeny ponořených vodních rostlin a vzácného druhu orchideje Pseudorchis albida. Pro stanovení diverzity a složení společenstev mykorhizních i nemykorhizních hub byly využity jak klasické metody kultivace symbiotických hub, tak moderní metody na kultivacích nezávislé. Na základě výsledků...Department of Experimental Plant BiologyKatedra experimentální biologie rostlinFaculty of SciencePřírodovědecká fakult

Plant Communities Rather than Soil Properties Structure Arbuscular Mycorrhizal Fungal Communities along Primary Succession on a Mine Spoil

Arbuscular mycorrhizal fungal (AMF) community assembly during primary succession has so far received little attention. It remains therefore unclear, which of the factors, driving AMF community composition, are important during ecosystem development. We addressed this question on a large spoil heap, which provides a mosaic of sites in different successional stages under different managements. We selected 24 sites of c. 12, 20, 30, or 50 years in age, including sites with spontaneously developing vegetation and sites reclaimed by alder plantations. On each site, we sampled twice a year roots of the perennial rhizomatous grass Calamagrostis epigejos (Poaceae) to determine AMF root colonization and diversity (using 454-sequencing), determined the soil chemical properties and composition of plant communities. AMF taxa richness was unaffected by site age, but AMF composition variation increased along the chronosequences. AMF communities were unaffected by soil chemistry, but related to the composition of neighboring plant communities of the sampled C. epigejos plants. In contrast, the plant communities of the sites were more distinctively structured than the AMF communities along the four successional stages. We conclude that AMF and plant community successions respond to different factors. AMF communities seem to be influenced by biotic rather than by abiotic factors and to diverge with successional age

Stationary device for vibrodiagnostics of passing vehicle

On the base of the carried out measurement in 2013 and 2014, the stationary measurement system has been developed for vibrodiagnostics of railway vehicles. This system is currently in a trial operation in Prague's subway. The principle of the railway vehicle bogie diagnostics is based on noise and vibration measurement of a railway superstructure. The measurement system is self-contained – it saves the measured data of a passed train automatically, including identification of the trainset and the each wheelset. The measured data are evaluated in the frequency domain, where failure symptoms are identified. The measurement repeatability makes possible application of a neural network for detection of the failure symptoms. The next phase of this project will concern to the application of the neural network. The function of the developed device and the principle of failure detection are described in this paper. The existing results of the carried out measurement are presented too

Temporal turnover of the soil microbiome composition is guild-specific

Although spatial and temporal variation are both important components structuring microbial communities, the exact quantification of temporal turnover rates of fungi and bacteria has not been performed to date. In this study, we utilised repeated resampling of bacterial and fungal communities at specific locations across multiple years to describe their patterns and rates of temporal turnover. Our results show that microbial communities undergo temporal change at a rate of 0.010-0.025 per year (in units of Sorensen similarity), and the change in soil is slightly faster in fungi than in bacteria, with bacterial communities changing more rapidly in litter than soil. Importantly, temporal development differs across fungal guilds and bacterial phyla with different ecologies. While some microbial guilds show consistent responses across regional locations, others show site-specific development with weak general patterns. These results indicate that guild-level resolution is important for understanding microbial community assembly, dynamics and responses to environmental factors.Peer reviewe

Impact of trees and forests on the Devonian landscape and weathering processes with implications to the global Earth's system properties – A critical review

Evolution of terrestrial plants, the first vascular plants, the first trees, and then whole forest ecosystems had far reaching consequences for Earth system dynamics. These innovations are considered important moments in the evolution of the atmosphere, biosphere, and oceans, even if the effects might have lagged by hundreds of thousands or millions of years. These fundamental changes in the Earth's history happened in the Paleozoic: from the Ordovician, the time of the first land plants, to the Carboniferous, dominated by forest ecosystems. The Devonian Plant Hypothesis (DPH) was the first concept to offer a full and logical explanation of the many environmental changes associated with the evolution of trees/forests that took place during this time period. The DPH highlighted the impact of deep-rooted vascular plants, particularly trees on weathering processes, pedogenesis, nutrient transport, CO2 cycling, organic and inorganic carbon deposition, and suggests further possible consequences on the marine realm (oceanic anoxia and extinction during the Late Devonian). Here we attempt to combine the DPH and the related expansion in biodiversity, the Devonian Plant Explosion (DePE), with the Biogeomorphic Ecosystem Engineering (BEE) concept. This idea connects tree growth and activity with initiation and/or alteration of geomorphic processes, and therefore the creation or deterioration of geomorphic landforms. We focus on trees and forest ecosystems, as the assumed dominant driver of plant-initiated change. We find that whereas there is a broad evidence of trees as important biogeomorphic ecosystem engineers, addressing the DPH is difficult due to limited, difficult to interpret, or controversial data. However, we argue the concept of BEE does shed new light on DPH and suggest new data sources that should be able to answer our main question: were Devonian trees Biogeomorphic Ecosystem engineers