XVI International Botanical Congess

Kariological study plays an important role in the cognition of ways of evolutions and genesis of flora, deciding number of taxonomic problems. Mitoses in root-tips of seedlings and adult plant (8-Hydroxyquinoline pretreatment, glacial acetic alhohol fixation, aceto-orcein staining, squash method) have been studied. Results: A karyologic study has been carried out on 47 species (more than 60%) of Scrophulariaceae family in Belarus. Different chromosome races have been defined for Veronica serpyllifolia L. (2n=14, 28). The chromosome numbers of Melampyrum polonicum (Beauverd) Soo (2n=18), Veronica poljensis Murb. (2n=18) and new chromosome race of Veronica heureka (M.A. Fisch) Tzvel. (2n=18), Verbascum lychnitis L. (2n=36) are determined for the first time. Conlusion: The chromosome numbers of the most of the species do not differ from those established in the other parts of areal. Scrophulariaceae family as well as all Belarusian flora is almost equally formed by diploids and polyploids. Kariological analysis is perspective for delimitation of species in taxanomically difficult groups.