Analyses of Plastome Sequences Improve Phylogenetic Resolution and Provide New Insight Into the Evolutionary History of Asian Sonerileae/Dissochaeteae

Abstract

Sonerileae/Dissochaeteae (Melastomataceae) comprises ca. 50 genera, two thirds of which occur in Southeast Asia. Phylogenetic relationships within this clade remain largely unclear, which hampers our understanding of its origin, evolution, and biogeography. Here, we explored the use of chloroplast genomes in phylogenetic reconstruction of Sonerileae/Dissochaeteae, by sampling 138 species and 23 genera in this clade. A total of 151 complete plastid genomes were assembled for this study. Plastid genomic data provided better support for the backbone of the Sonerileae/Dissochaeteae phylogeny, and also for relationships among most closely related species, but failed to resolve the short internodes likely resulted from rapid radiation. Trees inferred from plastid genome and nrITS sequences were largely congruent regarding the major lineages of Sonerileae/Dissochaeteae. The present analyses recovered 15 major lineages well recognized in both nrITS and plastid phylogeny. Molecular dating and biogeographical analyses indicated a South American origin for Sonerileae/Dissochaeteae during late Eocene (stem age: 34.78 Mya). Two dispersal events from South America to the Old World were detected in late Eocene (33.96 Mya) and Mid Oligocene (28.33 Mya) respectively. The core Asian clade began to diversify around early Miocene in Indo-Burma and dispersed subsequently to Malesia and Sino-Japanese regions, possibly promoted by global temperature changes and East Asian monsoon activity. Our analyses supported previous hypothesis that Medinilla reached Madagascar by transoceanic dispersal in Miocene. In addition, generic limits of some genera concerned were discussed.

Natural hybridization between Phyllagathis and Sporoxeia species produces a hybrid without reproductive organs

“…The most recent study clearly shows the taxonomic complexity and polyphyly of Phyllagathis and Sporoxeia and that the relationship between the parental species, P. longicalcarata and S. petelotii, is much closer than expected [28]. Both species appear to be nested in a mixed clade with P. hispidissima (C. Chen) C. Chen and other Sporoxeia species [28]. The "intergeneric" hybridization reported in this study provides another line of evidence for the close relationship between P. longicalcarata and S. petelotii, urging for more comprehensive phylogenetic studies aimed at clarifying the delimitation of Phyllagathis and Sporoxeia, in addition to many other taxa within the Sonerileae/Dissochaeteae.…”

“…The most recent study clearly shows the taxonomic complexity and polyphyly of Phyllagathis and Sporoxeia and that the relationship between the parental species, P. longicalcarata and S. petelotii, is much closer than expected [28]. Both species appear to be nested in a mixed clade with P. hispidissima (C. Chen) C. Chen and other Sporoxeia species [28].…”

A Guide to Curating New World Melastomataceae Collections with a Linear Generic Sequence to World-Wide Melastomataceae

“…The linear sequence provided here is based on a compilation of recent published and unpublished phylogenetic analyses (Clausing et al 2000, Clausing and Renner 2001a, Clausing and Renner 2001b, Michelangeli et al 2004, Amorim et al 2009, Penneys et al 2010, Michelangeli et al 2011, Goldenberg et al 2012, Penneys 2013, Penneys and Judd 2013a, Goldenberg et al 2015, Kriebel et al 2015, Rocha et al 2016a, Rocha et al 2016b, Veranso-Libalah et al 2017, Dellinger et al 2018, Rocha et al 2018, Veranso-Libalah et al 2018, Bacci et al 2019, Bochorny et al 2019, Guimarães et al 2019, Veranso-Libalah et al 2019, Wurdack and Michelangeli 2019, Zhou et al 2019a, Zhou et al 2019b. The number of species per genus and comments on generic limits are based on the systematic and/or monographic studies cited below.…”

“…However, early molecular systematics studies suggested that it may be more closely related or even embedded within the mostly Paleotropical Sonerileae Renner 2001b, Clausing andRenner 2001a). More recent analyses with increased taxon and loci sampling have placed it outside the Sonerileae (Zhou et al 2019a). Kartonegoro et al (submitted) provides a well-supported molecular phylogeny of the tribe supporting the recognition and circumscription of six genera of Dissochaeteae.…”

“…The group has a complicated taxonomic history with several small genera segregated and combined through the years (Cellinese 1997, Cellinese 1998. Recent phylogenetic analyses have shown that most of the currently recognized Old World genera are not monophyletic and the tribe is in dire need of a new taxonomic arrangement (Cellinese 1998, Kokubugata et al 2019, Zhou et al 2019a, Zhou et al 2019b. In light of these issues we have opted for separating the genera geographically and then order them alphabetically until the taxonomy is updated.…”