Plant Science and Biodiversity Centre SAS
Topic
A Study of the Evolutionary Processes Underlying Species Diversity in the Tribe Alysseae (Brassicaceae)
PhD. program
botany
Year of admission
2026
Name of the supervisor
RNDr. Stanislav Španiel, PhD.
Contact:
Receiving school
Faculty of Natural Sciences Comenius University
Annotation
Efficient conservation, as well as the potential economic use of wild plants, requires an understanding of their actual (often cryptic) species diversity and the evolutionary mechanisms underlying it. The research will focus primarily on wild species of the genera Alyssum and Odontarrhena (tribe Alysseae), which are suitable models for studying speciation processes and also have potential for practical applications. Members of both genera can thrive on ultramafic substrates, which are unsuitable for most other plant species. Moreover, Odontarrhena comprises the largest number of known species with the ability to hyperaccumulate heavy metals and is therefore a key model genus in research on phytoremediation (the remediation of environmental contamination using plants) and phytomining (the extraction of heavy metals, particularly nickel, using plants). Previously published studies have shown that the traditional taxonomic circumscription of species in both genera is largely artificial and inaccurate. Both genera exhibit extensive ploidy variation (ranging from diploid to octoploid cytotypes), substantial morphological diversity, a wide spectrum of ecological requirements (including different bedrock types and elevation ranges), and a broad geographic distribution spanning Eurasia and North Africa. The centre of their species diversity lies in the topographically heterogeneous (Sub-)Mediterranean region. The aim of the thesis is to elucidate phylogenetic and taxonomic relationships, as well as the evolutionary processes that shaped them, such as polyploidization, hybridization, allopatric speciation, and ecological diversification. A detailed examination of these processes has broader relevance beyond the studied genera and can contribute to a deeper understanding of plant speciation in general. The resulting data will also be incorporated into revised taxonomic circumscriptions of species or, where appropriate, may lead to the description of new taxa. An integrative methodological approach will be adopted, combining phylogenomic methods with flow cytometry, chromosome counting, multivariate morphometric analyses, and ecological niche modelling.