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Molecular biology of soil fungi participating in litter decomposition in forest ecosystems
Voříšková, Jana ; Baldrian, Petr (advisor) ; Gryndler, Milan (referee) ; Koukol, Ondřej (referee)
In forest ecosystems, substantial part of carbon enters soil in the form of plant litter. The decomposition of litter and soil organic matter represents an important process affecting nutrient cycling and carbon balance in soils. Fungi are considered the primary decomposers in terrestrial ecosystems due to the production of wide range of extracellular enzymes that allow them to attack the lignocellulose matrix in litter. Even if fungi represent key players in organic matter decomposition, the information about the structure and diversity of their communities is still limited and the roles of individual fungal taxa in forest soils remain unclear. This Ph.D. thesis focused on the characterization of fungal communities in forest soils and their potential to decompose plant litter. The method for in-depth analysis of complex microbial communities from environmental samples was established and used. In addition, single eukaryotic functional gene was analysed in soil for the first time at a depth that allowed reliable estimation of diversity. It was demonstrated that microbial community composition differs among horizons of forest soil profile. Despite similar diversity, significant differences in microbial community composition were observed between the DNA and RNA. Several microbial groups highly...
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Evolutionary ecology of the genus Geosmithia
Veselská, Tereza ; Kolařík, Miroslav (advisor) ; Gryndler, Milan (referee)
7 Abstract The genus Geosmithia Pitt (Ascomycota: Hypocreales) belongs to fungi living in symbioses with bark beetles. Its original strategy is association with phloeophagous bark beetles (Coleoptera: Scolytinae). The Geosmithia shows strong affiliation to vector (bark beetles) worldwide and the spectrum of host plants is delimitated by niche of vector. The genus includes the specialists to family Pinaceae, but also the generalists with wide range of host plants mainly belonging to broad-leaved trees. G. morbida changed its ecology from saprotrophic to pathogenic way of life and causes decline of Junglans nigra in the USA. Characteristics which allow its pathogenesis are not known. Another derived strategy, which occurred at least twice independently, is association with the ambrosia beetles. The ambrosia beetles create galleries in xylem with low nutritive value, and thus they cultivate ambrosia fungus, on which they are entirely nutritively dependent. The ambrosia fungi share convergent phenotype which leads to large terminal conidia and to ability of yeast growth. This master thesis is focusing on study of the features, which are important for individual ecological groups: the specialists to family Pinaceae, the pathogene, the ambrosia fungi and the generalists. It is becoming apparent that the most...
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Occurrence and significance of fungi associating with mycotrophic plants
Kohout, Petr ; Vohník, Martin (advisor) ; Gryndler, Milan (referee)
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...
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Fungi associated with tree roots
Charvátová, Markéta ; Baldrian, Petr (advisor) ; Gryndler, Milan (referee)
In contrast to the bulk soil environment, plant roots represent a habitat with higher nutrient availability due to the supply of photosynthesis-derived C-containing compounds. The roots thus support the life of various microorganisms that use such compounds, but the root-associated microbes in the same time may face a limitation in N and P availability. Unlike bacteria, many filamentous fungi are able to transport these compounds from soil and their mycelia thus typically extend into this environment. Ectomycorrhizal fungi are a typical example of this nutrition strategy. Tree roots produce exudates, that differ in thein composition for each species and they can also differ among individuals. It causes a high diversity of root-associated fungi. Soil is also inhabited by parasitic and saprotrophic fungi. Composition and activity of microbial communisies in the rhizosphere differ from the bulk soil. This work points at the differences of the rhizosphere and builk soil, the importance mycorrhizal fungi and it presents an overview of fungal species that have been found on the roots of spruce - Picea abies. Key words: fungi, mycorrhiza, soil, rhizosphere, Picea abies
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Decomposition of leaf litter by microscopic fungi in anthropogenic habitats
Bukovská, Petra ; Gryndler, Milan (referee) ; Kubátová, Alena (advisor)
V letech 2006 - 2008 byl na dvou antropogenních stanovištích s výskytem biologické půdní krusty proveden terénní experiment s listovým opadem břízy a modelovou celulózou využívající metodu opadových sáčků. Rychlost dekompozice opadu i celulolytická aktivita byla na obou stanovištích extrémně nízká. Diverzita společenstva mikroskopických hub na opadu, zjišťovaných izolační metodou a metodou inkubace opadu ve vlhkých komůrkách, však byla srovnatelná s diverzitou známou z přirozených lesních ekosystémů temperátního pásma. Také sukcesní změny společenstva hub pozorované na obou lokalitách odpovídaly v základních rysech údajům z jiných typů stanovišť. Metodou ITS-TRFLP kombinovanou s použitím taxonomicky specifických primerů byla odhalena značná diverzita chytridií a naopak jen velmi nízká diverzita bazidiomycetů. Na stanovišti s vyšší mírou antropogenního stresu byla zjištěna nižší diverzita hub, značně odlišná skladba společenstva a nižší dekompoziční aktivita. Na opadu studovaných stanovišť byly pozorovány i druhy, u kterých nebyla dosud známa tolerance k přítomným antropogenním stresům, a druhy dosud nepopsané. Powered by TCPDF (www.tcpdf.org)
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