Plastid phylogenomics of tribe Perseeae (Lauraceae) yields insights into the evolution of East Asian subtropical evergreen broad-leaved forests

Abstract

Background: The East Asian subtropical evergreen broad-leaved forests (EBLFs) harbor remarkable biodiversity. However, their historical assembly remains unclear. To gain new insights into the assembly of this biome, we generated a molecular phylogeny of one of its essential plant groups, the tribe Perseeae (Lauraceae). Results: Our plastid tree topologies were robust to analyses based on different plastid regions and different strategies for data partitioning, nucleotide substitution saturation, and gap handling. We found that tribe Perseeae comprised six major clades and began to colonize the subtropical EBLFs of East Asia in the early Miocene. The diversification rates of tribe Perseeae accelerated twice in the late Miocene. Conclusions: Our findings suggest that the intensified precipitation in East Asia in the early Miocene may have facilitated range expansions of the subtropical EBLFs and establishment of tribe Perseeae within this biome. By the late Miocene, species assembly and diversification within the EBLFs had become rapid.