Repeatome landscapes and cytogenetics of hortensias provide a framework to trace Hydrangea evolution and domestication

• DOI: 10.1093/aob/mcae184
• Publication Date: 2025-01-06T12:13:03Z
• Authors: Sara Ishiguro; Shota Taniguchi; Nicola Schmidt; Matthias Jost; Stefan Wanke; Tony Heitkam; Nobuko Ohmido
• Keywords: 580; info:eu-repo/classification/ddc/580

Abstract Background and Aims Ornamental hortensias are bred from a reservoir of over 200 species in the genus Hydrangea s.l. (Hydrangeaceae), valued gardens, households landscapes across globe. The phenotypic diversity hortensia cultivars, hybrids wild relatives is mirrored by their genomic variation, with differences genome size, base chromosome numbers ploidy level. We aim to understand chromosomal basis variation. Therefore, we analysed six different origins setups for repeatome divergence, fraction highest sequence turnover. This holds information hortensias’ evolutionary paths can guide breeding initiatives. Methods compiled genotype panel representing members sections Macrophyllae, Hydrangea, Asperae Heteromallae reconstructed plastome-based phylogenetic hypothesis as all our analyses. comprehensively characterized repeatomes whole-genome sequencing comparative repeat clustering. Major tandem repeats were localized multicolour FISH. Key Results show differing profiles reflecting separation into two major clades: diploid Japan conserved profile, distinguishing them Japanese polyploids well Chinese American hortensias. These results line phylogenies. presence specific indicates that H. paniculata was not polyploidized directly common ancestor species, but evolved distinct progenitor. satellite DNAs detected macrophylla chromosomes. Conclusions Repeat composition among varies congruence phylogeny. Identified species-specific satDNAs may be used cytogenetic markers identify infer parental old varieties. cytogenetics helps expand genetic toolbox tracing evolution guiding future breeding.