Fruit Evolution Is Key to Ecological Niches and Distribution Ranges Divergence in the Tribe Ligustrinae (Oleaceae)

ABSTRACT Aim To investigate how fruit type evolution influences ecological divergence, species diversification, and biogeographic history in tribe Ligustrinae (Oleaceae). Location Temperate and subtropical regions across the Northern Hemisphere. Taxon Tribe Ligustrinae, comprising Syringa and Ligustrum . Methods We reconstructed a robust phylogeny and estimated divergence times using plastome sequences. Ecological niches modelling and ancestral niche reconstruction were performed to infer habitat preferences. Biogeographic analyses and paleodistribution modelling were used to explore historical range dynamics and niche evolution across different fruit types. Results Capsules were primarily associated with humid, temperate regions, while drupes occupied broader ecological niches, expanding into warmer, humid subtropical zones. Biogeographic reconstruction indicated a north‐to‐south expansion of tribe Ligustrinae, coinciding with the transition from capsules to drupes. Paleodistribution models revealed fruit‐type‐specific ecological dynamics and niche expansion patterns over time. Main Conclusions Fruit type evolution in tribe Ligustrinae is closely linked to ecological divergence, lineage diversification, and biogeographic patterns. Drupes and capsules occupy distinct ecological niches and distributions, reflecting coordinated changes between reproductive traits and environmental adaptation. These findings highlight the combined role of fruit morphology and climatic factors in shaping plant diversity, adaptation, and distribution.