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Infection pathway of Hymenoscyphus fraxineus and its interactions with ash mycobiota
Haňáčková, Zuzana ; Koukol, Ondřej (advisor) ; Adamčíková, Katarína (referee) ; Botella Sánchez, Leticia (referee)
Ash dieback is a disease that affected populations of native ash species throughout Europe at the beginning of the 21st century. It causes necrotic spots on the leaves, necrosis of shoots and branches and, especially in young individuals, the total death of the tree. In particular, F. excelsior is attacked by ash dieback. The causative agent of the disease is the invasive ascomycete fungus from Asia - Hymenoscyphus fraxineus. The aims of this dissertation thesis were as follows: 1) to study population structure of H. fraxineus at different scales - at regional scale (Czech populations) and at the level of particular ash petioles, this latter was to serve as a confirmation of the pathogen infection pathway; 2) to elucidate the effect of H. fraxineus on saprotrophs in the litter (namely H. albidus) and 3) to compare endophytic mycobiota of tolerant and susceptible F. excelsior trees and to test antagonistic interactions of these fungi against the pathogen. Analysis of Czech populations showed lower average gene diversity compared to other European populations with one Czech population differing significantly from the rest due to the lowest allelic richness and very low average gene diversity. The results indicate that despite minimal differences among European populations, local ecological or...
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Mycorrhizal and endophytic roots of aquatic plants
Borovec, Ondřej ; Vohník, Martin (advisor) ; Kolařík, Miroslav (referee)
Interactions between fungi and plants can be found all around us. We would hardly find a plant neither containing a single hypha in its rhizosphere nor infested with a fungal pathogen. Whereas interactions of these organisms are well and described in terrestrial ecosystems, situation below the water level is completely different. The status of aquatic fungi and their relation to aquatic plants is to date not clear at all regarding difficulties of reaching them and huge value of terrestric interactions, which occupy most of the experts. All the basic plant-fungus interactions have been detected also underwater. As well as on the land, the most widespread aquatic mycorrhizal association is arbuscular mycorrhiza. On the contrary, the other well known mycorrhiza types such as orchid or ericoid mycorrhiza do not occur in the aquatic environment where their hosts are absent. On the other hand, endophytism is relatively frequent. Ascomycetous fungi with dark septate hyphae, collectively being referred to as "dark septate endophytes" (DSE), seem to be as abundant in the water as on the land. Additionally, aquatic plants are being challenged by numerous fungal parasites. AMF may play an important role in nutrient uptake of some plants from the aquatic environment. However, many species of aquatic plants are...
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Diversity and ecology of endophytic fungi in different parts of pants.
Kovaříčková, Adéla ; Prášil, Karel (advisor) ; Kolařík, Miroslav (referee)
Even though endophytic fungi have been studied intensively in the past years, little attention has been payed to endophytic colonisation of a whole plant. The search part of this work is about the differences in diversity and ecology of endophytes within whole plants, whose single parts represent qualitatively different environments for growth of endophytic fungi. The main difference is between the colonisation of systemic endophytes of grasses from family Clavicipitaceae and the colonisation of taxonomically heterogenous group of non-systemic endophytes. A systemic endophyte colonizes all above-ground organs of grass, while a non-systemic endophytes form only local infections, and their species composition in specific plant parts differs. The practical part of this work encompasses the pilot study of species diversity of endophytic fungi from woody parts (branches, stems and roots) of an elm tree (Ulmus laevis). There are differences in the frequency of colonisation among samples cultivated on agar plates, and also in diversity of isolated fungal genera.
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The effect of secondary metabolites (essential oils) on endophytic fungi from leaves of Rhododendron tomentosum
Koudelková, Barbora ; Koukol, Ondřej (advisor) ; Žabka, Martin (referee)
Rhododendron tomentosum is an evergreen shrub with a high content of secondary metabolites, particularly essential oils with antimicrobial effects. Diversity of endophytic fungi in this species and their possible adaptation to growth in the essential oil environment is not much explored. Therefore, the first aim of this thesis was to reveal the diversity of endophytic fungi colonising leaves of R. tomentosum on seven localities in the Czech Republic and one in Estonia. I isolated and determined (using comparison of ITS1 and ITS2 rDNA with the sequences from GenBank and morphological signs) 37 species of endophytic fungi. Among them the ubiquitous species colonising the most of the plants as endophytes were dominant. The second aim of my thesis was to explore whether the essential oil from R. tomentosum influences its endophytic fungi. The hypothesis that the strains obtained from R. tomentosum would be adapted to growth in the environment of the essential oil was postulated. I supposed that they would grow better on mediums with different concentrations of these chemical compounds added, in comparison with strains of the same species obtained from different substrates. Within four of seven species tested, the strains obtained from R. tomentosum grew better, but also on the medium without the...
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Fungal root symbionts of the seagrasses Posidonia oceanica (Posidoniaceae) and Thalassodendron ciliatum (Cymodoceaceae)
Soperová, Beáta ; Vohník, Martin (advisor) ; Mrnka, Libor (referee)
Seagrasses form an important part of the marine vegetation and its growth create a habitat for many other organisms. Equal to the terrestrial plants, seagrasses can associate with various fungal species ranging from the parasitic to the endophytic ones. Posidonia oceanica and Thalassodendron ciliatum, whose ontogenetic development are very similar, are considered to be the ones of the best studied seagrass. Seedlings of both species have a primary root densely covered with root hairs, which is later replaced by secondary roots. In the vast majority of cases, the adult P. oceanica and T. ciliatum do not form root hairs on the secondary roots. In the case of P. oceanica, this transition from roots with root hairs to roots lacking root hairs appears to be associated with interaction with endophytic fungi. The incidence of interaction with endophytic fungi is still unclear for T. ciliatum. A summary of existing knowledge of the root hairs and fungal root symbionts of P. oceanica and T. ciliatum has revealed an incomplete knowledge of the effect of endophytic fungi on roots and root hairs formation in P. oceanica and a complete absence of studies of T. ciliatum mycobionts. The summary has further led to the hypothesis of possible coevolution of endophytic fungi and seagrass P. oceanica.
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The effect of secondary metabolites (essential oils) on endophytic fungi from leaves of Rhododendron tomentosum
Koudelková, Barbora ; Koukol, Ondřej (advisor) ; Žabka, Martin (referee)
Rhododendron tomentosum is an evergreen shrub with a high content of secondary metabolites, particularly essential oils with antimicrobial effects. Diversity of endophytic fungi in this species and their possible adaptation to growth in the essential oil environment is not much explored. Therefore, the first aim of this thesis was to reveal the diversity of endophytic fungi colonising leaves of R. tomentosum on seven localities in the Czech Republic and one in Estonia. I isolated and determined (using comparison of ITS1 and ITS2 rDNA with the sequences from GenBank and morphological signs) 37 species of endophytic fungi. Among them the ubiquitous species colonising the most of the plants as endophytes were dominant. The second aim of my thesis was to explore whether the essential oil from R. tomentosum influences its endophytic fungi. The hypothesis that the strains obtained from R. tomentosum would be adapted to growth in the environment of the essential oil was postulated. I supposed that they would grow better on mediums with different concentrations of these chemical compounds added, in comparison with strains of the same species obtained from different substrates. Within four of seven species tested, the strains obtained from R. tomentosum grew better, but also on the medium without the...
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Mycorrhizal and endophytic roots of aquatic plants
Borovec, Ondřej ; Vohník, Martin (advisor) ; Kolařík, Miroslav (referee)
Interactions between fungi and plants can be found all around us. We would hardly find a plant neither containing a single hypha in its rhizosphere nor infested with a fungal pathogen. Whereas interactions of these organisms are well and described in terrestrial ecosystems, situation below the water level is completely different. The status of aquatic fungi and their relation to aquatic plants is to date not clear at all regarding difficulties of reaching them and huge value of terrestric interactions, which occupy most of the experts. All the basic plant-fungus interactions have been detected also underwater. As well as on the land, the most widespread aquatic mycorrhizal association is arbuscular mycorrhiza. On the contrary, the other well known mycorrhiza types such as orchid or ericoid mycorrhiza do not occur in the aquatic environment where their hosts are absent. On the other hand, endophytism is relatively frequent. Ascomycetous fungi with dark septate hyphae, collectively being referred to as "dark septate endophytes" (DSE), seem to be as abundant in the water as on the land. Additionally, aquatic plants are being challenged by numerous fungal parasites. AMF may play an important role in nutrient uptake of some plants from the aquatic environment. However, many species of aquatic plants are...
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Diversity and ecology of endophytic fungi in different parts of pants.
Kovaříčková, Adéla ; Prášil, Karel (advisor) ; Kolařík, Miroslav (referee)
Even though endophytic fungi have been studied intensively in the past years, little attention has been payed to endophytic colonisation of a whole plant. The search part of this work is about the differences in diversity and ecology of endophytes within whole plants, whose single parts represent qualitatively different environments for growth of endophytic fungi. The main difference is between the colonisation of systemic endophytes of grasses from family Clavicipitaceae and the colonisation of taxonomically heterogenous group of non-systemic endophytes. A systemic endophyte colonizes all above-ground organs of grass, while a non-systemic endophytes form only local infections, and their species composition in specific plant parts differs. The practical part of this work encompasses the pilot study of species diversity of endophytic fungi from woody parts (branches, stems and roots) of an elm tree (Ulmus laevis). There are differences in the frequency of colonisation among samples cultivated on agar plates, and also in diversity of isolated fungal genera.
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