Raw sequence reads of Campylotropis
The shrub genus Campylotropis, comprising approximately 40 species, belongs to the subtribe Lespedezinae within the Fabaceae family. This genus is primarily distributed in the temperate and subtropical regions of East Asia, with its center of diversity in the Hengduan Mountains and southern China. However, historical limitations in sampling and research methodology have obscured its evolutionary history and species relationships. This study presents the most comprehensive phylogenomic analysis of Campylotropis to date, including 91 samples from 42 taxa. Using data from 77 plastid genes and 1,233 single-copy nuclear genes (SCNGs), we reconstructed the phylogenetic relationships within the genus, estimated divergence times, inferred ancestral area distributions, and traced the evolution of its morphological traits. Our results strongly support the monophyly of Campylotropis, distinguishing it from closely related genera. Within Campylotropis, we identified six well-supported clades and clarified previously unresolved relationships within the genus. Global climate change and tectonic activities since the late Miocene have driven the lineage diversification of Campylotropis, while Quaternary climate fluctuations have led to rapid radiation within the genus. Ancestral area reconstruction indicated that Campylotropis originated in the Hengduan Mountains and southern China, subsequently spreading rapidly to adjacent regions in East Asia. Integrating extensive sampling and nuclear genomic data, this study elucidates the evolutionary history of Campylotropis and contributes to our understanding of diversification processes in biodiversity hotspots.