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Introgressive zone of Arabidopsis lyrata and A. arenosa in Central Europe
Hojka, Jakub ; Marhold, Karol (advisor) ; Španiel, Stanislav (referee)
Genetic composition of hybrid zones often reflects geographical and ecological gradients. Hybrid zone of Arabidopsis lyrata and A. arenosa in Central Europe can be convenient model system for testing such hypothesis. These are well circumscribed but still interfertile, and their offspring is fully fertile. Besides repeated hybridisation events, the current state is complicated by the autopolyploidisation events of one of the parents, namely A. lyrata, which is present in the area studied both as diploid and tetraploid. This hybrid zone was already described in previous publications, which showed certain gradient of introgression. Moreover, the area of the hybrid zone represents a transition between Alpine and Pannonian climate along an altitudinal gradient leading from the Prealps to the lowland Wienerwald. The current thesis is the as yet most detailed study of this hybrid zone both in respect of number of studied populations and the amount of data acquired using the methods of RAD Sequencing, multivariate morphometrics and flow cytometry. The analysis of genetic data showed a gradient of introgression, where parental populations are placed at opposite ends, whereas genetically intermediate hybrids are placed in its centre. Analysis of the genome size showed an additional gradient, where hybrids...
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Flow cytometry and its use for study of insects
Stuchlíková, Magdalena ; Janšta, Petr (advisor) ; Sadílek, David (referee)
Flow cytometry is a modern technique in research, playing a significant role in biomedicine and botanics. Despite its benefits (speed, simplicity, low costs), flow cytometry is currently not used in the study of insects on a large scale. This thesis gives an overview as to how flow cytometry is used in research on insects and summarises the results of such study. This pertains to genome size and its connections to other phenomena. Other focal points of research, such as ploidy and base pair ratios, are addressed to a lesser extent. Key words: flow cytometry, use in study of insects, genome size, ploidy, invertebrates
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An assessment of interspecific hybridization between Central-European taxa from the genus Nymphaea: insights from flow cytometry and multivariate morphometrics
Kabátová, Klára
Although the genus Nymphaea (waterlily) includes only two native species (N. alba and allopolyploid N. candida) in Central Europe, it poses a great challenge to taxonomy and biosystematics. The determination of both species is hampered by their phenotypic similarities, and species boundaries can be further blurred by interspecific hybridization. In addition, ornamental cultivars of different parentage that often escape (either accidentally or intentionally) from cultivation and can cross with the native ones make the situation even more complex. To get insight into the caryological and phenotypic variability of czech waterlilies, we used DNA flow cytometry and both distance-based and geometric morphometrics. Collections from natural sites showed two different groups of fluorescence intensities, corresponding to N. alba and N. candida, respectively. In addition, intermediate values of nuclear DNA amount were found in some plants from South Bohemia, indicating their hybrid origin. Morphologically, these plants were partly intermediate between the native species, partly having their separate tendency to oversized growth. Surprisingly, ornamental cultivars (obtained either from commercial stocks or as escapes from the field) possessed the smallest genome sizes. The amount of nuclear DNA therefore seems...
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Genome size evolution in Costaceae
Böhmová, Alžběta ; Fér, Tomáš (advisor) ; Rybka, Vlastimil (referee)
Genome size in plants varies greatly; in angiosperms this variability can make a 2400- fold difference. This is why the subject of many studies is the attempt to explain these differences in various contexts. One of these is the phylogenetic viewpoint, which studies the relationships between genome size and different taxonomic groups. Many studies have been published so far which explore the plants of the temperate zone; there are however very few studies investigating genome size in tropical plants. For this reason, the subject of this thesis is the analysis of genome size in the pantropical family Costaceae Nakai. This family presently includes seven genera: Monocostus K.Schum., Dimerocostus Kuntze, Costus L., Paracostus C.D.Specht, Chamaecostus C.D.Specht & D.W.Stev, Hellenia Retz. and Tapeinochilos Miq., counting altogether about 300 species. The family is sister to the family Zingiberaceae, which has been notably better explored due to its economic importance. One of the aims of this thesis was a partial revision of the phylogeny published by Specht (2006). Molecular methods were used to analyse the phylogenetic relationships; these methods included classical sequencing of the trnL-F region and next-generation sequencing, where probes designed in advance were used to obtain the targeted genes....
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Interspecific hybridization between Pulsatilla pratensis and P. patens
Krejčová, Nikol ; Suda, Jan (advisor) ; Kaplan, Zdeněk (referee)
This thesis deals with interspecific hybridization in sympatric populations of Pulsatilla patens and P. pratensis. The key aim was to assess karyological and phenotypic variation in the study group. DNA flow cytometry revealed three non-overlapping groups of genome sizes, corresponding to P. patens, P. × hackelii and P. pratensis. The frequency of interspecific hybridization was low, accounting to approx. 3% of analyzed plants. Morphometric analyses identified a set a reliable species-specific characters, including number of divisions the leaf, length of petiole the part of leaf, number of smaller parts of leaf and colour of blossom. Although the majority of hybrid individuals flowered and set fruits, their fertility was reduced considerably. The threat from interspecific hybridization to parental species is therefore rather low.
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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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Polyploid speciation of the genus Anthoxanthum in Europe
Khodlová, Zuzana ; Trávníček, Pavel (advisor) ; Štech, Milan (referee)
Eight of fifteen species in genus Anthoxanthum (Poaceae) can be found in Europe. Five of them are perennials forming A. odoratum complex, the remaining three are annual, more or less mediterranean taxa (A. aristatum, A. ovatum and A. gracile). Within the A. odoratum s. l. complex the following taxa are distinguished: widely spread A. odoratum s. str. (4x; 2n = 20), arcto-alpine A. alpinum (2x a 4x; 2n = 10 and 20), Madeiran endemic species A. maderense (2x; 2n = 10), endemic species of Balkan mountains A. pauciflorum (2x; 2n = 10) and the Iberian peninsula endemic A. amarum (?x; 2n ~ 90). The aim of this thesis is to clearify the unknown evolutionary relationships between the taxa, between the annuals and perennials, diploids and polyploids. The following questions should be answered in this study: 1) What is the origin and distribution of the rediscovered diploid perennial taxon and what is its relationship to the other members of the group; 2) What is the distribution pattern of the perennial taxa of the genus Anthoxanthum in Europe and what is their haplotype differenciation (overall distribution of the taxa and haplotypes and the existence of their sympatric occurence); 3) What evolutionary ties exist among the species and what is the origin of allotetraploid taxon A. odoratum s.str. The...
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An assessment of interspecific hybridization between Central-European taxa from the genus Nymphaea: insights from flow cytometry and multivariate morphometrics
Kabátová, Klára ; Suda, Jan (advisor) ; Rybka, Vlastimil (referee)
Although the genus Nymphaea (waterlily) includes only two native species (N. alba and N. candida) in Central Europe, it poses a great challenge to taxonomy and biosystematics. The determination of both species is hampered by their phenotypic similarities, and species boundaries can be further blurred by interspecific hybridization. In addition, ornamental cultivars of different parentage often escape from cultivation and make the situation even more complex. To get insight into the caryological and phenotypic variability of czech waterlilies, the DNA flow cytometry and both distance-based and geometric morphometrics were used. Collections showed two different groups of fluorescence intensities, corresponding to N. alba and N. candida, respectively. In addition, intermediate values of nuclear DNA amount were found in some plants from South Bohemia, indicating their hybrid origin. Surprisingly, ornamental cultivars possessed the smallest genome sizes. The amount of nuclear DNA therefore seems to be a promising species-specific marker that enables not only native species but also cultivars to be distinguished. Cytometrically-proven individuals have been subjected to multivariate morphometrics, and high differenciation was discovered especially between native species. More complicated seems the distinction...
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Dispersal, distribution and genetic diversity of Melampyrum subalpinum group
CHLUMSKÝ, Jan
This thesis is focused on the dispersal, distribution, and genetic diversity of the taxonomically highly diverse Melampyrum subalpinum group. A complete revision of the localities of M. subalpinum in the Czech Republic and Slovakia is presented. The genetic variation and population structure of the M. subalpinum group across its distribution range is described based on allozymes, nuclear and chloroplast gene sequencing, and genome size. Signs of historical hybridization with M. nemorosum were found in some populations. A comparison of seed dispersal by ants between the co-occurring M. subalpinum and M. pratense and the influence of differences in this process are presented. A new mean of seed dispersal (endozoochory) is introduced for Melampyrum. Myrmecochorous dispersal distances are tested and Holocene migration possibilities are discussed taking into account endozoochory.
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