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Ecophysiological significance of root-fungus symbioses in Mediterranean seagrasses
Borovec, Ondřej ; Vohník, Martin (advisor) ; Gryndler, Milan (referee)
Seagrasses are the only group of submerged plants that are permanently growing in marine environment. They play an important role in the sea bottom ecosystem. Seagrasses are primary producers capable of accumulation and deposition of carbon. They influence water flow at the sea bottom and form symbioses with variety of organisms. Our knowledge of symbiotic interactions of seagrasses is still limited even though several studies of the topic have been carried out in recent years. Unlike most of terrestrial plants, seagrasses are generally considered as plants that do not form any specific associations with mycorrhizal or endophytic fungi. Surprisingly, we have discovered a novel fungal endophytic association in roots of Mediterranean endemic seagrass species Posidonia oceanica (L.) Delile. Morphology of this symbiotic fungi strongly resembles common symbiotic fungi of terrestrial plants, dark septate endophytes (DSE). We sampled roots of P. oceanica in large area of the Mediterranean from southeastern Spain to Albania and described range and taxonomical classification of the endophyte using microscopy, in vitro cultivation and molecular determination. Roots of P. oceanica in whole area of study are colonized by mere two endophytic fungal species. Over 90 % of the fungal symbionts belong to a single...
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Can anatomy and morphology of seagrass root systems predict their colonization by symbiotic fungi?
Bulínová, Marie ; Vohník, Martin (advisor) ; Votrubová, Olga (referee)
Seagrasses are narrow ecological and taxonomic group of plants which evolved from terrestrial ancestors some 100 million years ago. Unlike most terrestrial plants they are traditionally considered as a group not forming mycorrhizal symbioses or specific root endophytic associations. However, this opinion is likely biased by a very low number of studies targeting this group of vascular plants. For example, an anatomically and morphologically unique endophytic fungal symbiosis was recently discovered in the roots of the Mediterranean endemic species Posidonia oceanica, a species that is considered to be one of the best studied. It thus seems that more specialized research can yield similar results, i.e. discoveries of new fungal association in seagrasses. This could have a big impact on our opinions regarding not only mineral nutrition of these fascinating plants. The aims of this thesis therefore are 1) to summarize published information about fungal associations in the roots of seagrasses, 2) to summarize basic knowledge of anatomy and morphology of the roots of individual groups of seagrasses and 3) an attempt to predict seagrass groups where we may more likely assume presence of fungal associations. Special emphasis will be placed on the genus Posidonia which has an evolutionary origin in the...
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The importance of mycorrhizal fungi in primary succession
Nevěčná, Michaela ; Münzbergová, Zuzana (advisor) ; Püschel, David (referee)
Primary succession is a relatively long-term process of colonization of a certain area, which has never been influenced by any biotic environmental elements. There are many factors that influence primary succession. One of them are mycorrhizal fungi. Establishment of mycorrhizal symbiosis, i. e. a mutualistic relationship between plants and mycorrhizal fungi, can be an important factor facilitating development of vegetation cover. Plants profit from mycorrhizal symbiosis thanks to increased nutrient acquisition, protection against toxic heavy metals or an advantage in a competition with non-mycorrhizal plants. Being non-photosynthetic organisms, fungi gain assimilates from the plants. Modification of the course of primary succession by adding mycorrhizal fungi can have a big importance in reclamation of the areas damaged by mining and there is a potential to substitute, at least partly, technical reclamations.
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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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Wood wide web - plant mycelial interconnections
Antl, Tomáš ; Vohník, Martin (advisor) ; Kolaříková, Zuzana (referee)
Mycorrhizal mycelium may form a continuous network (commnon mycorrhizal network - CMN) and connect a number of plants or even entire community in an ecosystem. In the Plant World, CMNs have a number of important physiological and ecological consequences. The present work aims to create a review on current knowledge of CMNs and the associated Wood Wide Web. The next objective is to evaluate the results of individual observations and experiments that have been made on this topic. The introductory chapters 1 and 2 describe the various types of mycorrhizal symbioses (i.e., arbuscular mycorrhiza, orchid mycorrhiza, ectomycorrhiza, ericoid and monotropoid mycorrhiza), their characteristics and ability to create CMNs. The following chapters 3 and 4 describe ecophysiological consequences of common mycorrhizal networks such as maintaining stability of plant populations, invasive plants which exploit CMNs, plant communities and the hypothesis of meta-networks. Mycorrhizal mycelium allows transfer of various substances between two plants. The transferred substances include mineral nutrients (especially nitrogen and phosphorus), but also carbon organic compounds, water, signal substances, etc. The last part summarizes the knowledge on CMN, discusses the advantages and disadvantages of different experimental...
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