Delimitation of the genus Margaritopsis (Rubiaceae) in the Asian, Australasian and Pacific region, based on molecular phylogenetic inference and morphology

摘要: In the past, circumscription of large genus Psychotria (Rubiaceae) was difficult, until molecular phylogenetic studies revealed its considerable paraphyly, enabling delimitation major lineages and grouping related genera, most notably separation relatives (former Psychotrieae) into two tribes: Psychotrieae Palicoureeae. The Margaritopsis, which is included in Palicoureeae, encompasses 27 Neotropical species, previous these have been shown to be close a group eight species that occur over region extending from South-East Asia tropical South Pacific through Malesia (= AMP region, defined as including Asia, Malesia, Australia, Melanesia, Micronesia, New Caledonia Polynesia). A study, using one nuclear DNA (ITS) four plastid regions (ndhF, rps16, trnH-psbA, trnT-F), undertaken order test placement 17 within results show they form monophyletic clade G), also includes monotypic Fijian Readea Hodgkinsonia frutescens Australia. Clade G embedded well-supported grade with five representatives Margaritopsis. morphological survey based on twenty characters, potential circumscribe generic entities, shows monophyly supported by character combination similar confirming their inclusion this genus. Taxonomic nomenclatural work required formalize implications. Based same set but absence data, 28 other were detected likely candidates for allowing estimation richness minimum 47 species. Within G, subclades lineage are delimited each generally unique features. Phylogenetic topologies reveal biogeographical patterns, main route dispersal western eastern parts subsequent dispersals between archipelagos region.