Department of Taxonomy

Head: Mgr. Zdeněk Kaplan, Ph.D.

People ׀ Projects ׀ Publications

Research topics

Systematics and taxonomy of vascular plants:

  • Revision and synthesis of plant diversity
  • Taxonomic monographs
  • Plant evolution and phylogenetic relationships
  • Evolutionary and ecological consequences of genome size variation
  • Reproductive systems and microevolution

Systematics, taxonomy and ecology of lichens and fungi (lichenized and non-lichenized fungi):

  • Diversity, ecology and evolution of lichens
  • Protection of lichens
  • Taxonomy and systematics of ascomycetes

Selected recent results

1/ A strikingly high species diversity on the Roof of the World: the genus Taraxacum in Ladakh

A detailed exploration of Ladakh, a mountain region situated in a rain shadow of the Great Himalaya Range, revealed a twice higher plant species diversity than previously known. The monograph of the model genus Taraxacum encompasses 120 species, of which 50 were discovered as new. This study revealed that the West Himalaya represents one of the world centres of the Taraxacum diversity, with a number of endemic and morphologically and evolutionarily isolated species.

  • Kirschner J., Štěpánek J., Klimeš L., Dvorský M., Brůna J., Macek M. & Kopecký M. 2020. The Taraxacum flora of Ladakh, with notes on the adjacent regions of the West Himalaya. Phytotaxa 457: 1-409. doi: 10.11646/phytotaxa.457.1.1

  
Taraxacum dilutissimum Kirschner & Štěpánek, one of the most widespread species in Ladakh, which was, however, scientifically unknown until recently.

 

2/ Parallel alpine differentiation in Arabidopsis arenosa

Parallel evolution provides powerful natural experiments for studying repeatability of evolution and genomic basis of adaptation. Well-documented examples from plants are, however, still rare. Arabidopsis arenosa, a predominantly foothill species with scattered morphologically distinct alpine occurrences is a promising candidate. We sampled foothill and alpine populations in all regions known to harbor the alpine ecotype and used SNP genotyping to test for repeated alpine colonization. We combined field surveys and a common garden experiment to quantify phenotypic parallelism. Genetic clustering by region and coalescent simulations demonstrated parallel origin of alpine ecotype in four mountain regions. Alpine populations exhibited parallelism in height and floral traits. In contrast, leaf traits were distinctive only in certain region(s), reflecting a mixture of plasticity and genetically determined non-parallelism. We demonstrate varying degrees and causes of parallelism and non-parallelism across populations and traits within a plant species. Parallel divergence along a sharp elevation gradient makes A. arenosa a promising candidate for studying the genomic basis of adaptation.

  • Knotek A., Konečná V., Wos G., Požárová D., Šrámková G., Bohutínská M., Zeisek V., Marhold K. & Kolář F. Parallel alpine differentiation in Arabidopsis arenosa. Frontiers in Plant Science 2020, 11:561526. doi: 10.3389/fpls.2020.561526

 Alpine morphotype of Arabidospsi arenosa from four mountain ranges: (A) Niedere Tauern, (B) Vysoké Tatry, (C) Rodna, (D) Făgăraș.
Alpine morphotype of Arabidospsi arenosa from four mountain ranges: (A) Niedere Tauern, (B) Vysoké Tatry, (C) Rodna, (D) Făgăraș.

 

3/ Evolutionary relationships within the aquatic plant genus Callitriche

Despite a number of unique environmental adaptations, aquatic plants are considerably underrepresented in contemporary biosystematic studies. Moreover, the determination and taxonomic evaluation of aquatic plants is intricate due to the strong morphological reduction and a high degree of phenotypic plasticity. We reconstructed the phylogenetic relationships within the notoriously challenging aquatic genus Callitriche. We demonstrated that most of the recognized Callitriche species are genetically well defined, despite their similar morphologies. In at least three species we discovered and proved the occurrence of cryptic, previously unknown genetic lineages. Two species are probably allopolyploids, i.e. they arose through hybridization and subsequent genome duplication. We also detected four interspecific hybrids, two of which we described as new to science.

  • Prančl J.,  Fehrer J., Caklová P., Bambasová V., Lučanová M. & Kaplan Z. Intricate evolutionary history of Callitriche (Plantaginaceae) taxa elucidated by a combination of DNA sequencing and genome size. Taxon 2020, 69: 1016–1041. doi: 10.1002/tax.12315

Porost hvězdoše Callitriche obtusangula. Foto J. Prančl
Floating leaf rosettes of blunt-fruited water starwort (Callitriche obtusangula).

 

4/ New insights into the systematics of Chaetosphaeriales and Savoryellales

Microscopic fungi of Chaetosphaeriales and Savoryellales are important components of ecosystems inhabiting decaying wood and leaves. We focused on traditionally broadly conceived Bactrodesmium and Chaetosphaeria. Research based on phylogenetic analyses, culture and morphological studies enabled to evaluate important taxonomic traits and placement of both genera. After 155 years since the description, we successfully collected B. abruptum, type species of the genus, which prompted a revision of the genus. We discovered that conidia secede rhexolytically, exhibiting multiple secession patterns. We stabilized the generic concept of Bactrodesmium in Savoryellales, while unrelated species were transferred to new genera Aphanodesmium, Gamsomyces and Kaseifertia. Although the morphology of sexual states of most Chaetosphaeria is relatively uniform, their asexual states show variability and evolutionary change. An exception to this morphological monotony is the group of species defined by the unique wall of the fruit body and the morphology of the needle-like spores. We resurrected the genus Paragaeumannomyces in Chaetosphaeriaceae, where these former Chaetosphaeria species were transferred.

  • Réblová M., Nekvindová J., Fournier J. & Miller A. N. Delimitation, new species and teleomorph-anamorph relationships in Codinaea, Dendrophoma, Paragaeumannomyces and Striatosphaeria (Chaetosphaeriaceae). MycoKeys 2020, 74: 17–74. doi: 10.3897/mycokeys.74.57824

Coloured fruit bodies of representatives of Paragaeumannomyces and a vertical section of the wall exhibiting a unique three-layered structure.
Coloured fruit bodies of representatives of Paragaeumannomyces and a vertical section of the wall exhibiting a unique three-layered structure.