HIDDEN DRIVERS OF HETEROZYGOSITY IN CIRSIUM (ASTERACEAE)

• Authors: MAHADURA Ashini Dias; ŠMERDA Jakub; ZEDEK František; BUREŠ Petr
• Year of publication: 2026
• Type: Conference abstract
• MU Faculty or unit: Faculty of Science
• Description: HIDDEN DRIVERS OF HETEROZYGOSITY IN CIRSIUM (ASTERACEAE) Ashini Dias Mahadura* , Jakub Šmerda, František Zedek, Petr Bureš* Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic *[e-mail] / [e-mail] Heterozygosity, as a fundamental component of genetic diversity, is shaped by complex interactions among reproductive systems, life-history strategies, hybridization, and polyploidy. Yet, the relative contribution of these factors remains poorly understood across species-rich plant genera. Here, we investigate genome-wide patterns of heterozygosity in 17 Central European species of Cirsium (Asteraceae), a genus characterized by exceptional diversity in sexual systems (hermaphroditism, gynodioecy, and dioecy), life histories (monocarpic versus polycarpic), ploidy levels, and extensive interspecific hybridization [1,2]. Using restriction-site associated DNA sequencing (RAD-seq), we quantify heterozygosity across species and evaluate the effects of female frequency, life history, hybrid origin, and polyploidy. Field surveys revealed pronounced interspecific variation in female frequency. Genome-wide analyses demonstrated that monocarpic species consistently exhibit reduced heterozygosity compared to polycarpic species. In contrast, species with documented histories of hybridization and polyploidy show markedly elevated heterozygosity, highlighting the pivotal role of genome duplication and interspecific gene flow in shaping genetic diversity within Cirsium. Our results reveal that heterozygosity in Cirsium is not driven by a single trait but emerges from the interplay of life history, reproductive biology, and genomic architecture. These findings underscore the evolutionary significance of hybridization and polyploidy as hidden yet powerful drivers of genetic diversity in flowering plants. REFERENCES [1] P. Bureš et al., Preslia. 82 (2010) 391–422. [2] P. Bureš et al., Plant Biol J. 26 (2024) 749-763.