Polymorphism of Birches in the Southern Trans-Urals

Area of Science:

• Botany
• Genetics
• Taxonomy

Background:

• The genus Betula (birch) presents taxonomic challenges, with some researchers recognizing microspecies like Betula krylovii.
• Traditional phenotype-based studies often struggle to resolve complex classifications within Betula.

Purpose of the Study:

• To comprehensively assess genetic and morphological polymorphism in Southern Trans-Urals birch populations.
• To clarify the taxonomic status of Betula krylovii in relation to Betula pendula.

Main Methods:

• Examined ploidy levels, chloroplast DNA fragment variability, and leaf blade morphology.
• Sampled birch populations across 10 sites along the Tobol River.

Main Results:

• Observed moderate genetic polymorphism and low interpopulation differentiation in Betula pendula.
• Inferred low occurrence of Betula pubescens from ploidy data.
• Identified similar phenotypic traits, common chlorotypes, and identical ploidy levels (2n) between B. pendula and B. krylovii.

Conclusions:

• The findings suggest that Betula krylovii may not be a distinct species.
• The taxonomic status of B. krylovii warrants further revision based on integrated genetic and morphological evidence.