Molecular phylogeny and taxonomy of the Betula L. genus ((10/2018 – 9/2022)

Birches are common pioneer trees and shrubs of the temperate and boreal zones in the Northern Hemisphere. They are important components of the European forest ecosystems and have multiple economic uses but are not as well-studied as other tree species.
Birches comprise a highly diverse and notoriously difficult taxonomic group because of their high morphological variation, phenotypic plasticity and frequent interspecific hybridization. That is why exact taxonomic and phylogenetic relations among species within the Betula L. genus remain unclear. Number of taxa and their range vary greatly from 30 to over 120 species in the world flora and from 7 to 30 species in Europe alone depending on the source.
The main project objective is to infer the most realistic phylogenetic relationships in the Betula L. genus using modern experimental genomic methods and phylogenomic approaches. To achieve this aim, we plan to develop a new phylogenomic approach that will be based on single-copy and conserved orthologous genes with the aim to create new phylogenomic markers that can be used to study phylogenetic relationships and assess species diversity in birch. The taxonomic structure and phylogenetic relations inside the Betula L. genus will be reconstructed by applying a combination of different methods and approaches: molecular genetics and genomics, morphological, and karyological. This project is predominantly focused on birch species and populations in Europe, but also will include worldwide species for references. We would like to better understand phylogenetic relationships between birch species and to develop a tool of less ambiguous hybrid taxa delineation. This will be done by analyzing multiple samples from different populations of all accessible species and by integrating different methods.
We plan to apply the NGS-approach and comparative sequence analysis to identify putative single-copy and conserved orthologous genes combined with using supertree phylogenetic reconstruction methods to integrate different genetic markers in reconstruction of phylogenetic relationships and generating phylogenetic tree.
Additionally, this work can also help to decipher speciation processes in plants with weak or absent reproductive barriers, such as birch species.