Format: ORAL

Terezie Mandkov1, Michael D. Windham2, Martin A. Lysak1

1 Central European Institute of Technology, Masaryk University, Brno, Czech Republic 2 Department of Biology, Duke University, Durham, NC, USA

The genus Boechera (Brassicaceae) comprises approximately 480 genetically distinct taxa, predominantly distributed in North America. Characterized by a basic chromosome number of x= 7, the genus includes diploid sexuals (2n = 14), diploid apomicts (2n = 14, 15), and triploid apomicts (2n = 21, 22). The extensive morphological diversity within the genus arises from frequent hybridization among diploid species, leading to the emergence of apomictic diploid hybrids. Triploids have independently arisen through hybridization between sexual and apomictic diploids. Notably, apomictic Boechera plants feature two heterochromatic B-like chromosomes (Het and Del). With a small genome size, close evolutionary ties to Arabidopsis, and the coexistence of diploid sexual and apomictic lines, Boechera stands as a unique model system for exploring genomic changes associated with apomixis. This study, employing cutting-edge cytogenomics and phylogenomics approaches, delves into the genome structure and evolutionary dynamics of sexual and apomictic Boechera plants. By unveiling the origins of chromosomes linked with apomixis, our findings contribute valuable insights into the broader cytogenetic foundations of apomixis, advancing our understanding of reproductive strategies in plants. This work was supported by the Czech Science Foundation (grant number 24-11371S).