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Hybridization of crab apple with domestic apple trees
Portl, Jiří ; Fér, Tomáš (advisor) ; Prančl, Jan (referee)
This bachelor thesis summarizes known information about hybridization (anthropohybridization) crab apple with orchard apple. Next it follows up mainly genetic and morphometric methods that haven't been used in the hybridization studies yet. Crab apple (Malus sylvestris) is the only one wild species in Malus genus in Europe. However in the last few decades these populations are endangered by orchard apple (Malus ×domestica), that originates from central Asia. It often outspreads into the free nature and thereby closer to wild apple plants, that leads to easier hybridization of these two woods. This process leads up to decreasing number of genetically pure crab apple individuals and also to slow hybrid plants expansion. This trend, which was called anthropohybridization, can be observed also in the Prunus genus, where there hybridizes wild species European dwarf cherry Prunus fruticosa with tart cherry Prunus cerasus. Recent studies though refers to following genetic aspects of Malus domestica, namely formation by triple hybridisation. Several locations of crab apple were observed and analysed in Europe in the last few years for study of anthropohybridization degree with Malus ×domestica. There were observed hybrid plants in common with genetically pure Malus sylvestris. Key words: crab apple,...
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Watermilfoils (Myriophyllum) in the central Europe
Hrdinová, Magdalena ; Trávníček, Pavel (advisor) ; Prančl, Jan (referee)
Genus Myriophyllum L. (watermilfoil) belongs to one of the most species-rich genera within Haloragaceae (Saxifragales). It includes three invasive species, which are of major concern - European M. spicatum L., North American M. heterophyllum MICHX. and South American M. aquaticum (VELL.) VERDC. All of them occur in Central Europe as well as native M. verticillatum L. and M. alterniflorum DC. lacking more significant invasive growth up to now. It is not only its invasivness that makes genus Myriophyllum so fascinating. It also displays extremely high phenotypic plasticity which is accompanied by determination difficulties. Moreover, recent research indicates that Myriophyllum tends to hybridize producing more invasive hybrids than parental taxa. Such traits pose a formidable challenge to scientists to deal with possible future invasive growth of non-indigenous Myriophyllum species in Central Europe. Therefore, thorough study of factors influencing evolution success of plants should be conducted. One of the key factors seems to be polyploidy. Research into polyploidy offers a new approach to watermilfoil issues. Additionally, according to preparatory study all native Central European Myriophyllum species can be easily distinguished by flow cytometry. That enables to study polyploidy in an...
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Reproductive interactions between diploids and triploids of flowering rush (Butomus umbellatus) and their evolutionary potential for mediating inter-ploidy gene flow
Petříková, Eliška ; Čertner, Martin (advisor) ; Prančl, Jan (referee)
Contact zones of cytotypes harbour a unique opportunity to study the dynamics and evolution of mixed-ploidy systems. Butomus umbellatus (flowering rush) is one of a few species in which diploid and triploid cytotype is present in nature. The first known mixed-ploidy populations of B. umbellatus were discovered in south-eastern Slovakia during the previous studies. Common occurrence of the species in an area with substantially natural dynamics of wetland ecosystems represents a unique model system for unbiased comparisons of traits and genetic diversity between diploid and triploid individuals along with their dispersal capabilities on a landscape level. The main aim of of this thesis is to uncover the truth behind evolutionary processes that are taking place in the contact zone of diploid and triplioid cytotype of B. umbellatus in south-eastern Slovakia. Using flow cytometry and molecular methods (microsatellites) we will test whether this is a primary or secondary contact zone and assess the level of genetic variability between individuals and populations of both cytotypes. Using the analysis od microsatellite loci we discovered that the contact zone of cytotype is of both primary and secondary character and gene flow between cytotypes was also detected. These results were supported by high production and...
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Evaluation of cryptic diversity in the group of thread-leaved water-crowfoot (Ranunculus trichophyllus agg.)
Hanzlíčková, Johana ; Prančl, Jan (advisor) ; Chrtek, Jindřich (referee)
Ranunculus trichophyllus agg. (thread-leaved water crowfoot) represents a taxonomically challenging group of aquatic plants in which the presence of several significantly different genotypes and the genome size variation have been recently revealed. The results of previous studies suggest that cryptic taxa occur in this group, being so far overlooked due to considerable morphological reduction and extensivephenotypic plasticity. In this thesis, the variation and genetic relationships of four morphologically similar homophyllous water-crowfoot species was critically assessed in the area of Central Europe, using a combination of modern biosystematic methods (flow cytometry, direct DNA sequencing, morphometric analyses), specially focusing on the complex of R. trichophyllus.. The genome size analysis via flow cytometry was confirmed as a suitable method for determining the studied species; further, several hybrid combinations were revealed using this approach. However, recent interspecific hybridization is rather infrequent in the interest group. The results of DNA analyses indicate an importance of hybridization events in the evolution of sect. Batrachium: all the polyploid taxa studied are probably of allopolyploid origin. Two cryptic taxa within the traditionally recognized species R. trichophyllus have...
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Evolutionary processes responsible for complexity in aquatic vascular plants
Prančl, Jan ; Kaplan, Zdeněk (advisor) ; Oberprieler, Christoph (referee) ; Štech, Milan (referee)
Aquatic plants are a heterogeneous assemblage of species that, although surviving in similar habitats, have evolved from very different genetic and ecological backgrounds. However, many aquatics share a number of anatomical, morphological, metabolic and reproductive adaptations, which have arisen independently in remarkable similarities (through convergence and parallelisms) in many unrelated groups. Despite their evolutionary uniqueness, aquatic plants are markedly underrepresented in contemporary biosystematic studies. Moreover, the taxonomic evaluation of numerous aquatic plant groups is intricate due to the strong morphological reduction and a high degree of phenotypic plasticity. This thesis focuses on two notoriously challenging aquatic plant groups, Callitriche and Ranunculus sect. Batrachium. The combination of several approaches (genome size estimation, chromosome counting, sequencing of nrDNA ITS and plastid trnT-trnL regions, examination of herbarium collections) was applied in order to improve our knowledge on principal evolutionary processes such as hybridization, polyploidization and cryptic variation and demonstrate their role on the shaping of overall aquatic plant diversity. The distribution of particular species in the Czech Republic was mapped for the first time. For both groups,...
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The patterns of local adaptation to serpentine bedrock in plant populations
David, Jan ; Čertner, Martin (advisor) ; Prančl, Jan (referee)
For sessile organisms such as plants, substrate specialization acts a very important role, because plants have no choice when choosing a suitable substrate. Plants can respond very specifically to substrate, and local adaptations often begin to emerge, especially if their substrate composition is completely different from the parent substrate in which the plant grows usually. The thesis deals specifically with the problem of serpentine populations, the challenges that these plants have to deal with, and the local adaptations that arise in these populations. Keywords: Serpentinophyte, serpentine, serpentine endemism, local adaptation
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Evolution and systematics of water-crowfoots (Ranunculus sect. Batrachium)
Hanzlíčková, Johana ; Prančl, Jan (advisor) ; Bílá, Jana (referee)
Water-crowfoots (Ranunculus sect. Batrachium) are among the most complicated groups of aquatic angiosperms. Processes such as polyploidization (there are five known ploidy levels) and hybridization play the main role in evolution of the subgenus, resulting into thereticulate evolution of the whole genus Ranunculus. Furthermore, newly established hybrids and polyploids can be fixed in nature via clonal growth or autogamy. Fenotypic plasticity and considerable morphological reduction contribute to the taxonomic complexity of the group and in combination with microevolutionary processes lead to the existence of cryptic variation.Therefore it can be said that the current taxonomic classification is dubious and requires a revision. The thesis also includes a brief introduction to the cryptic species complex Ranunculus trichophyllus agg. and a description of methods which will be applied in following master thesis.
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Hybridization of crab apple with domestic apple trees
Portl, Jiří ; Fér, Tomáš (advisor) ; Prančl, Jan (referee)
This bachelor thesis summarizes known information about hybridization (anthropohybridization) crab apple with orchard apple. Next it follows up mainly genetic and morphometric methods that haven't been used in the hybridization studies yet. Crab apple (Malus sylvestris) is the only one wild species in Malus genus in Europe. However in the last few decades these populations are endangered by orchard apple (Malus ×domestica), that originates from central Asia. It often outspreads into the free nature and thereby closer to wild apple plants, that leads to easier hybridization of these two woods. This process leads up to decreasing number of genetically pure crab apple individuals and also to slow hybrid plants expansion. This trend, which was called anthropohybridization, can be observed also in the Prunus genus, where there hybridizes wild species European dwarf cherry Prunus fruticosa with tart cherry Prunus cerasus. Recent studies though refers to following genetic aspects of Malus domestica, namely formation by triple hybridisation. Several locations of crab apple were observed and analysed in Europe in the last few years for study of anthropohybridization degree with Malus ×domestica. There were observed hybrid plants in common with genetically pure Malus sylvestris. Key words: crab apple,...
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