摘要
The genus Salix is a common component of the Northern Hemisphere dendroflora with important ecological and economic value.However,taxonomy and systematics of Salix is extremely difficult and relationships between main lineages,especially deep phylogenies,remain largely unresolved.In this study,we used genome-skimming,plastome assembly,and single-copy orthologs(SCOs)from 66 Salix accessions,along with publicly available plastome and sequence read archive(SRA)datasets to obtain a robust backbone phylogeny of Salix,clarify relationships between its main lineages,and gain a more precise understanding of the origin and diversification of this species-rich genus.The plastome and SCO datasets resolved Salix into two robust clades,with plastome-based phylogenies lacking inner resolution and SCO offering fully resolved phylogenies.Our results support the classification of Salix into five subgenera:Salix,Urbaniana,Triandrae,Longifoliae and Vetrix.We observed a significant acceleration in the diversification rate within the Chamaetia-Vetrix clade,while Salix exhibited increased rates of diversification spanning from the early Oligocene to the late Miocene.These changes coincided with contemporaneous tectonic and climate change events.Our results provide a foundation for future systematic and evolutionary studies of Salix.Additionally,we showed that genome skimming data is an efficient,rapid,and reliable approach for obtaining extensive genomic data for phylogenomic studies,enabling the comprehensive elucidation of Salix relationships.
基金
supported by NSFC(32070226,32360065)
the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U23A20149)
the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2024QZKK0200)
Yunnan Fundamental Research Projects(202101AS070032)
the CAS“Light ofWest China”Program(xbzg-zdsys-202110)
the Yunnan Innovation Team Project(202305AS350004,with LD/NY/SB/CJG/CJH as the core member).
