Genetic diversity and conservation significance of the endangered endemic Oreocharis cotinifolia across Danxia-like landscapes

Danxia-like landforms resemble typical Danxia landforms in landscape structure and biodiversity but differ only in tectonic background and erosion processes. Oreocharis cotinifolia is an endangered plant species with a limited distribution, confined to the Danxia-like region of the Dayao Mountains in Guangxi, China. To support effective conservation, we investigated its genetic diversity, population structure, and demographic history with ddRAD-seq. A total of 128 individuals from eight populations were analyzed, generating 17,033 single nucleotide polymorphisms (SNPs). The results revealed low genetic diversity, pronounced population structure, and limited gene flow, with populations clustered into two major genetic groups. Demographic analyses indicated a severe population contraction approximately 300 years ago, succeeded by a gradual recovery beginning around 200 years ago. Our findings suggest that habitat fragmentation, anthropogenic disturbance, and restricted dispersal have jointly shaped the current genetic landscape of O. cotinifolia . This research provides a scientific foundation for the conservation administration of this species and offers valuable insights for safeguarding endemic and endangered plants in fragmented Danxia-like landscapes.