Towards a species-level phylogeny for Neotropical Myrtaceae: Notes on topology and resources for future studies

Abstract

Premise: Increasingly complete phylogenies underpin studies in systematics, ecology,and evolution. Myrteae (Myrtaceae), with ~2700 species, is a key component of theexceptionally diverse Neotropical flora, but given its complicated taxonomy,automated assembling of molecular supermatrices from public databases often leadto unreliable topologies due to poor species identification.Methods: Here, we build a taxonomically verified molecular supermatrix ofNeotropical Myrteae by assembling 3909 published and 1004 unpublished sequencesfrom two nuclear and seven plastid molecular markers. We infer a time calibratedphylogenetic tree that covers 712 species of Myrteae (~28% of the total diversity in theclade) and evaluate geographic and taxonomic gaps in sampling Results: The tree inferred from the fully concatenated matrix mostly reflects thetopology of the plastid data set and there is a moderate to strong incongruencebetween trees inferred from nuclear and plastid partitions. Large, species rich generaare still the poorest sampled within the group. Eastern South America is the best represented area in proportion to its species diversity, while Western Amazon,Mesoamerica, and the Caribbean are the least represented.Conclusions: We provide a time calibrated tree that can be more reliably used toaddress finer scale eco evolutionary questions that involve this group in theNeotropics. Gaps to be filled by future studies include improving representation oftaxa and areas that remain poorly sampled, investigating causes of conflict betweennuclear and plastid partitions, and the role of hybridization and incomplete lineagesorting in relationships that are poorly supported.