Research

Our research covers the study of evolutionary mechanisms in plants in the broadest sense, including biosystematics, taxonomy, ecology and phytogeography. We employ a broad spectrum of methods from field investigations, through ecological and hybridization experiments, morphometrics, flow cytometry and modern cytogenetics, to diverse molecular methods, including NGS techniques. Our group collaborates with the Institute of Botany of the Czech Academy of Sciences in Průhonice. Specific topics of our research are listed below.

Our research would of course not be possible without grant projects and collaboration with institutions abroad.

Research groups

Plant ecological genomics - https://botany.natur.cuni.cz/ecolgen/
Filip Kolář, Emma J. Morgan, Guillaume Wos, Magdalena Holcová, Veronika Konečná, Magdalena Lučanová, Doubravka Požárová
We are interested in the evolutionary processes shaping diversity in natural plant populations. The main focus of our group is to reveal triggers and evolutionary consequences of whole genome duplication, and parallel environmental shifts across multiple populations. To do so, we combine a wide range of genetic (genome resequencing, RNAseq, flow cytometry) and ecological (field surveys, chamber and transplant experiments) approaches. We build our hypotheses using comprehensive knowledge of range-wide natural variation of our study systems, primarily wild members of the leading plant model genus Arabidopsis . This enables us to leverage the extensive knowledge on Arabidopsis thaliana to understand the links between the variation observed in the field and the genomic, functional and eco-physiological background of our study species.

Genome size, polyploidy and reproductive strategies of alpine plants along cordilleras in the Americas
Petr Sklenář, Tomáš Urfus and Jan Ptáček
Our group is interested in genome size variability, polyploidy and reproductive strategies of alpine plants of Andes in Ecuador, Bolivia and Argentina with comparison to Rocky Mountains in the USA. We use Flow Cytometry for evaluation of the absolute genome size and DNA ploidy level. We use FCSS (Flow Cytometric Seed Screening) to test angiosperm reproductive modes and combination of in vitro cultures of gametophytes and Flow Cytometry to find out the breeding system of ferns.

Microevolutionary processes of cryptogamous plants
Tomáš Urfus, Kristýna Hanušová and Jan Ptáček
We are focus on polyploidization, hybridization and reproductive strategies within ferns and lycophytes. Our methods are in vitro cultures of gametophytes, Flow Cytometry (all part of fern life cycle – sporophytes, spores, gametophytes), morphometrics, morphological observation (spore abortion index, exospore length) and experimental crossing between gametophytes. We cooperate with Faculty of Science, University of South Bohemia (Libor Ekrt).

Apomixis research group
Patrik Mráz, Jindřich Chrtek, Matthias Hartmann, Viera Mrázová, Ladka Paštová, Jan Pinc, Pavel Zdvořák
Apomixis (agamospermy) is an asexual reproduction of plants by means of seeds which are formed from the unreduced female gametes parthenogenetically. Although apomixis is relatively rare, being found in ca 2.2 % of angiosperm genera, in those groups where it occurs it seems to be very successful. Apomixis is tightly coupled with interspecific hybridization and polyploidization, and provides a reproductive assurance in otherwise sterile hybrids. Furthermore, apomixis represents one of the most effective reproduction barriers and therefore it plays an important role in plant speciation. Despite its evolutionary significance we know still little about its origin, expression, transfer to sexual congeners and impact on fitness, distribution (geographical parthenogenesis) and adaptive potential of apomitic lineages.
Using representatives of the genera Hieracium L. (s.str.) characterized by diplosporic apomixis and in less extent also Pilosella Hill with aposporic apomixis (both Asteraceae, tribus Lactuceae) we study evolutionary and ecological aspects of apomictic reproduction. To these aims and in close collaboration with Judith Fehrer and Alexander Belyayev's research groups from the Institute of Botany, the Czech Academy of Sciences in Průhonice, we use large spectrum of methodological approaches starting from field survey, ecological field or greenhouse experiments, experimental hybridization, multivariate morphometrics, herbarium revisions and embryology, and ending with genetic analyses which cover karyology (including fluorescense and genomic in situ hybridization), flow cytometry, molecular fingerprinting and phylogenetic analyses based on single or multicopy genes, including next generation sequencing methods. An importnat part ouf our work are taxonomic revisions of selected species groups providing a basis for evaluation of diversity and distributional patterns.

Selected publications

  • Belyayev A, Paštová L, Fehrer J, Josefiová J, Chrtek J, Mráz P. 2018. Mapping of Hieracium (Asteraceae) chromosomes with genus-specific satellite DNA elements derived from next generation sequencing data. Plant Systematics and Evolution (in press). https://doi.org/10.1007/s00606-017-1483-y
  • Chrtek J Jr. 1997. Taxonomy of the Hieracium alpinum group in the Sudeten Mts., the West and the Ukrainian East Carpathians. Folia Geobotanica et Phytotaxonomica 32: 69–97.
  • Chrtek J jun. 2004. Hieracium L. – jestřábník. In: Slavík B, Štěpánková J (eds.), Květena České republiky 7: 540–701, Academia, Praha.
  • Chrtek J jun, Mráz P & Severa M. 2004. Chromosome numbers in selected species of Hieracium s.str. (Hieracium subgen. Hieracium) in the Western Carpathians. Preslia 76: 119–139.
  • Chrtek J, Plačková I. 2005. Genetic variation in Hieracium alpinum (Asteraceae) in the Krkonoše Mts (West Sudeten Mts, Czech Republic). Biologia (Bratislava) 60: 387–391.
  • Chrtek J jr, Tomková M, Mráz P, Marhold K, Plačková I, Krahulcová A, Kirschner J. 2007. Morphological and allozyme diversity in the Hieracium nigrescens group (Compositae) in the Sudety Mountains and the Western Carpathians. Botanical Journal of the Linnean Society 153: 287–300.
  • Chrtek J jun, Mráz P. 2007. Taxonomic revision of Hieracium nigrescens agg. in the Western Carpathians. Preslia 79: 45–62.
  • Chrtek J, Zahradníček J, Krak K, Fehrer J. 2009. Genome size in Hieracium subgenus Hieracium (Asteraceae) is strongly correlated with major phylogenetic groups. Annals of Botany 104: 161–178.
  • Chrtek J, Hartmann M, Mrázová V, Zdvořák P, Štefánek M, Mráz P. 2018. Seed traits, terminal velocity and germination in sexual diploid and apomictic triploid Hieracium alpinum (Asteraceae): are apomicts better dispersers? Flora 240: 76–81.
  • Fehrer J, Krak K, Chrtek J. 2009. Intra-individual polymorphism in diploid and apomictic polyploid hawkweeds (Hieracium, Lactuceae, Asteraceae): disentangling phylogenetic signal, reticulation, and noise. BMC Evolutionary Biology 9: 239.
  • Frey DJ, Haag CR, Kozlowski G, Tison J-M, Mráz P. 2012. High genetic and morphological diversity despite range contraction in the diploid Hieracium eriophorum (Asteraceae) endemic to the coastal sand dunes of South-Western France. Botanical Journal of the Linnean Society 169: 365–377.
  • Hand ML, Vít P, Krahulcová A, Johnson SD, Oelkers K, Siddons H, Chrtek J, Fehrer J, Koltunow AMG. 201. Evolution of apomixis loci in Pilosella and Hieracium (Asteraceae) inferred from the conservation of apomixis-linked markers in natural and experimental populations. Heredity 114: 17–26.
  • Hartmann M, Štefánek M, Zdvořák P, Heřmann P, Chrtek J, Mráz P. 2017. The Red Queen hypothesis and geographical parthenogenesis in the alpine hawkweed Hieracium alpinum (Asteraceae). Biological Journal of the Linnean Society 122: 681–696.
  • Herben T, Trávníček P, Chrtek J. 2016. Reduced and unreduced gametes combine almost freely in a multiploidy systém. Perspectives in Plant Ecology, Evolution and Systematics 18: 15–22.
  • Mráz P. 2003. Mentor effects in the genus Hieracium s.str. (Compositae, Lactuceae). Folia Geobotanica 38: 345–350.
  • Mráz P, Szeląg Z. 2004. Chromosome numbers and reproductive systems in selected species of the genera Hieracium L. and Pilosella Hill. (Asteraceae) from Romania. Annales Botanici Fennici 41: 405–414.
  • Mráz P, Paule J. 2006. Experimental hybridization in the genus Hieracium sstr (Asteraceae): crosses between selected diploid taxa. Preslia 78: 1–26.
  • Mráz P, Šingliarová B, Urfus T, Krahulec F. 2008. Cytogeography of Pilosella officinarum (Compositae): Altitudinal and longitudinal differences in ploidy level distribution in the Czech Republic and Slovakia and the general pattern in Europe. Annals of Botany 101: 59–71.
  • Mráz P, Chrtek J, Šingliarová B. 2009. Geographical parthenogenesis, genome size variation and pollen production in the arctic-alpine species Hieracium alpinum. Botanica Helvetica 119: 41–51.
  • Mráz P, Chrtek J, Fehrer J. 2011. Interspecific hybridization in the genus Hieracium s.str. – evidence for bidirectional gene flow and spontaneous allopolyploidization. Plant Systematics and Evolution 293: 237–245.
  • Peckert T, Chrtek J, 2006. Mating interactions between coexisting diploid, triploid and tetraploid cytotypes of Hieracium echioides (Asteraceae). Folia Geobotanica 41: 323–334.
  • Rotreklová O, Krahulcová A, Mráz P, Mrázová V, Mártonfiová L, Peckert T & Šingliarová B. 2005. Chromosome numbers and breeding systems in some species of Hieracium subgen. Pilosella from Europe. Preslia 77: 177–195.
  • Šingliarová B, Hodálová I, Mráz P. 2011. Biosystematic study of the diploid-polyploid Pilosella alpicola group with variation in breeding system: patterns and processes. Taxon 60: 450–470.
  • Šingliarová B, Chrtek J, Plačková I, Mráz P. 2011. Allozyme variation in diploid, polyploid and mixed-ploidy populations of the Pilosella alpicola group (Asteraceae): relation to morphology, origin of polyploids and breeding systém. Folia Geobotanica 46: 387–410.
  • Šingliarová B, Šuvada R, Mráz P. 2013. Allopatric distribution, ecology and conservation status of the Pilosella alpicola species group (Asteraceae). Nordic Journal of Botany 31: 122–128.
  • Trávníček P, Dočkalová Z, Rosenbaumová R, Kubátová B, Szeląg Z, Chrtek J. 2011. Bridging global and microregional scales: ploidy distribution in Pilosella echioides (Asteraceae) in Central Europe. Annals of Botany 107: 443–454.
  • Zahradníček J, Chrtek J. 2015. Cytotype distribution and phylogeography of Hieracium intybaceum (Asteraceae). Botanical Journal of the Linnean Society 179: 487–498.

Research topics

The main research topics of our unit are:

Evolutionary mechanisms of polyploid complexes

Duplication of whole sets of chromosomes (polyploidization) is one of the key processes in the evolution of new species. It also plays a crucial role in the breeding of new cultivars of agricultural and ornamental plants. In our research we focus on the study of the evolutionary histories of polyploid complexes in the European flora as well as in the floras of subtropical (South Africa) and tropical (South America, Southeast Asia) regions. Moreover, we study the co-occurrence of different cytotypes under natural conditions and the reproductive, morphological and ecological consequences of polyploidization.


Evolution of rare, endangered and endemic species in the Czech flora

The study of rare plants brings interesting theoretical information (e.g. about the principles underlying the evolution of plant species) as well as specific practical results that can be utilized in nature conservation. We study the mechanisms by which species arise within the area of Czechia, i.e. the country’s sub(endemic) taxa. We also use morphometrics, cytometry and genetic techniques to study the hybridization of species, be it rare or common.


Evolutionary history in the context of Quaternary climatic changes

The alteration of glacial and interglacial periods has substantially influenced the distribution and evolution of plant species. Survival through periods of unsuitable conditions in so-called refugia and the directions of subsequent migrations are some of the key topics of evolutionary biology, especially of the discipline called phylogeography. We focus on reconstructing the evolutionary histories of selected species after the last glaciation, especially in Central and Northern Europe (the Alps, the Carpathians and Scandinavia). We take a wide range of molecular approaches allowing to study the distribution of genetic variability in detail.


Evolutionary diversification in world biodiversity centres (Southern American alpine region, Cape floristic region)

The Andes are one of the world’s biodiversity hotspots. In our research we focus on the evolution of plant species in the highest elevated tropical ecosystems – the páramos. We are interested in the mechanisms generating large numbers of species and their adaption to extreme conditions at high elevations (together with other research groups within the Department of Botany).



Dynamics of plant genome size evolution

Plants exhibit stunning differences in the amount of DNA in the cell nucleus. The intrinsic causes of this variability, the mechanisms of its heritability as well as its ecological and evolutionary consequences are largely unknown. The study of genome size evolution is a rapidly evolving field of plant evolutionary biology, mainly thanks to the easy applicability of flow cytometry. Our research is focused on the genome size evolution of selected taxonomic and ecological groups. Its results are later complemented by crossing and ecological experiments as well as by the outcomes of molecular studies.


Evolution, diversity and dispersal of water and wetland plants

Water and wetland plants are interesting not only from a biosystematic point of view, but also provide model examples for the study of basic evolutionary mechanisms and processes. Some genera of aquatic and waterlogged habitats include large species complexes in dire need a new biosystematic treatment (e.g. Batrachium, Bolboschoenus or Callitriche). Aquatic and wetland plants also serve as groups for the study of basic principles in the fields of population ecology and genetics (e.g. different ways of dispersal in different types of water environments, structure of clonal populations) and microevolutionary processes such as hybridization or polyploidization.


Dynamics and evolution of reproductive strategies, especially apomixis

Apomixis (i.e. clonal reproduction through seeds) is common in many plant groups (Asteraceae, Poaceae, Rosaceae, etc.). Apomixis leads to the formation of numerous reproductively isolated lineages that are hard to distinguish morphologically. In genera where apomixis is common (e.g. Hieracium, Rubus and Taraxacum), thousands of (micro-)species have been described. Current research into apomictic plants is focused on the study of microevolutionary mechanisms and processes.


Floristic research in Central Europe

Floristic research is an integral part of botany. As part of field surveys, we determine and document the occurrence of plant species in Czechia and the rest of Central Europe. The results of these surveys are incorporated into databases and red lists, and also serve as a basis for comprehensive publications such as regional floras. Without good floristic research, modern biosystematics would be unable to identify topics to deal with. Floristic data are also commonly used for effective nature conservation.


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