Genetic diversity of Bulgarian representatives of genus Carduus L. (Asteraceae) as revealed by variability in sequences of internal transcribed spacers region

ABSTRACTThe biodiversity of genus Carduus in Bulgaria is grossly under-studied with modern methods, which leads to unclear status of species and hampers the assessment of their habitats and conservation status. In this study, we used the variability of internal transcribed spacers (ITS) to investigate the biodiversity of Carduus species collected from different floristic regions of Bulgaria. Thirty-three samples were processed. Among the studied species, C. acanthoides exhibited the highest ITS variability (eight single nucleotide polymorphisms were found). High ITS variability was also found in C. crispus and C. hamulosus, demonstrating that some of the local Carduus species possesses unique genetic diversity, which can serve as source for future divergence of new forms and subspecies. For each species, unique nucleotides suitable as molecular taxonomy markers were identified. However, C. nutans and C. thoermeri displayed completely identical ITS sequences, which is in agreement with all ITS sequences of...