Delimitation of Sauropus (Phyllanthaceae) based on plastid matK and nuclear ribosomal ITS DNA Sequence data.
OBJECTIVE
A recent molecular phylogenetic study showed that Sauropus is deeply embedded within Phyllanthus together with its allies, Breynia and Glochidion. As relationships within Sauropus are still problematic and the relationship with Breynia has long been doubted, more molecular data are needed to test/corroborate such a broad definition of Phyllanthus. This study aims to clarify the status and delimitation of Sauropus and establish its position within Phyllanthaceae.


METHODS
Plastid matK and nuclear ribosomal ITS DNA sequence data for Sauropus and its allies were used to construct phylogenetic trees using maximum parsimony and Bayesian methods.


RESULTS
Within Phyllanthus, Sauropus can be split into the mainly south-east Asian Sauropus sensu stricto (s.s.) plus Breynia and the mainly Australian Sauropus (formerly Synostemon). Sauropus s.s. plus Breynia comprise two distinct clades; one is the combination of Sauropus sections Glochidioidei, Sauropus and Schizanthi and the other is the combination of Sauropus sections Cryptogynium and Hemisauropus and the monophyletic genus Breynia.


CONCLUSIONS
Molecular data indicate that Synostemon should be reinstated at the same level as Sauropus s.s. and that Sauropus s.s. should be united with Breynia under the latter, older name. The molecular data corroborate only two of the five infrageneric groups of Sauropus recognized on the basis of morphological data.
National Herbarium of the Netherlands, Leiden University, PO Box 9514, 2300 RA Leiden, The Netherlands. pruesapan@nhn.leidenuniv.nl
Kanchana
K
Pruesapan
Ian R H
IR
Telford
Jeremy J
JJ
Bruhl
Stefano G A
SG
Draisma
Peter C
PC
Van Welzen
D001483:Base Sequence; D002467:Cell Nucleus / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D017343:Genes, Plant; D029803:Phyllanthus / Q000235:genetics*; D010802:Phylogeny; D018087:Plastids / Q000235:genetics*
D021903:DNA, Ribosomal Spacer