Marcelo Reginato

Untangling the phylogeny of Leandra s.str. (Melastomataceae, Miconieae)

Phylogenetic studies in Melastomataceae have demonstrated the need for taxonomic rearrangements in the current classification. Nonetheless, melastomes are among the most diverse groups of plants and several cases of known artificial taxa have been observed and awaiting further resolution. The Leandra s.str. clade, with ca. 200 species, includes the majority of the taxa traditionally treated in the genus Leandra and is almost restricted to eastern Brazil. In earlier studies, some attempts have been made to infer the relationships within Leandra s.str., but the sampling was sparse and the resolution low inside the clade. Here, we attempt to provide an improved phylogenetic hypothesis for this group on which to base further studies. Specifically, we provide a comprehensive taxon sampling and attempt to infer a species tree for this group, dissecting potential noise in the phylogenetic reconstruction, such as paralogy, rogue taxa, hybridization and incomplete lineage sorting. Our data set includes 126 ingroup species (192 terminals) and four partitions (six markers). We implement the (∗)BEAST model for species tree inference and perform several simulation methods to assess model fit and to discuss potential causes for the observed patterns. Major lineages of Leandra s.str. were delineated, a strictly bifurcating species tree model seems to not account for the observed data, and hybridization is very likely an important evolutionary force in this group.

The first complete plastid genomes of Melastomataceae are highly structurally conserved

Background In the past three decades, several studies have predominantly relied on a small sample of the plastome to infer deep phylogenetic relationships in the species-rich Melastomataceae. Here, we report the first full plastid sequences of this family, compare general features of the sampled plastomes to other sequenced Myrtales, and survey the plastomes for highly informative regions for phylogenetics. Methods Genome skimming was performed for 16 species spread across the Melastomataceae. Plastomes were assembled, annotated and compared to eight sequenced plastids in the Myrtales. Phylogenetic inference was performed using Maximum Likelihood on six different data sets, where putative biases were taken into account. Summary statistics were generated for all introns and intergenic spacers with suitable size for polymerase chain reaction (PCR) amplification and used to rank the markers by phylogenetic information. Results The majority of the plastomes sampled are conserved in gene content and order, as well as in sequence length and GC content within plastid regions and sequence classes. Departures include the putative presence of rps16 and rpl2 pseudogenes in some plastomes. Phylogenetic analyses of the majority of the schemes analyzed resulted in the same topology with high values of bootstrap support. Although there is still uncertainty in some relationships, in the highest supported topologies only two nodes received bootstrap values lower than 95%. Discussion Melastomataceae plastomes are no exception for the general patterns observed in the genomic structure of land plant chloroplasts, being highly conserved and structurally similar to most other Myrtales. Despite the fact that the full plastome phylogeny shares most of the clades with the previously widely used and reduced data set, some changes are still observed and bootstrap support is higher. The plastome data set presented here is a step towards phylogenomic analyses in the Melastomataceae and will be a useful resource for future studies.

monographaR: An R package to facilitate the production of plant taxonomic monographs

Taxonomic data are essential in many fields of biology. However, the production of taxonomic treatments is usually very time consuming and few programs are available for taxonomic use. The R-based package monographaR automates the production of some ubiquitous components of plant taxonomic studies, generating a monograph skeleton and figures for publication. The package includes functions to convert tables into taxonomic descriptions, lists of collectors, and examined specimens. Additionally, wrapper functions to batch generate phenology histograms and distributional maps are also available. Automated workflows, such as the one provided by the monographaR package, can facilitate the production of taxonomic treatments, potentially increasing the dynamics of taxonomic data generation and preventing format mistakes in repetitive tasks that are otherwise performed manually.

New species of Behuria, Miconia, and Ossaea (Melastomataceae) from Eastern Brazil

Abstract Three species that occur in montane forests in Eastern Brazil are described here. Behuria capixaba occurs in the state of Espírito Santo and Ossaea loligomorpha in Bahia, while Miconia dorsaliporosa occurs in both states.

A taxonomic revision of Pleiochiton (Melastomataceae, Miconieae)

The genus Pleiochiton has frequently been recognized by dubious characters and seldom treated in taxonomic and floristic surveys. Nevertheless, monophyly of the genus has been highly supported by recent molecular and morphological data, and it can be morphologically recognized by the epiphytic growth and succulent roots. Following the current circumscription, the genus has 12 species, all endemic to the Atlantic Forest sensu stricto in eastern Brazil. The species occur in well conserved middle elevation forests and most are narrowly distributed, with four recorded from only a single locality. In this paper we present a taxonomic revision of the genus and provide an identification key, distribution maps, descriptions, and illustrations for all species. The new species P. amorimii is described, and the known distribution of the genus is expanded northwards, into the “brejos de altitude” of Pernambuco state.

Taxonomic notes on Leandra (Melastomataceae, Miconieae)

In this paper we propose 11 synonyms and six lectotypes for eastern Brazilian species of Leandra. Leandra urophylla and L. nutans are placed in the synonymy of L. acutiflora; Leandra atropurpurea in the synonymy of L. australis; Ossaea ramboi in the synonymy of L. catharinensis; Leandra pulchra in the synonymy of L. clidemioides; Leandra furfurella in the synonymy of L. cordigera; Leandra macrosepala in the synonymy of L. laevigata; Leandra dusenii in the synonymy of L. microphylla; Leandra dolichodons in the synonymy of L. penduliflora; Leandra dasytricha and L. mosenii in the synonymy of L. variabilis. We also propose lectotypes for L. australis, L. atropurpurea, L. cordigera, L. dusenii, L. laevigata, and L. pulchra.

Diversity and constraints in the floral morphological evolution of Leandra s.str. (Melastomataceae)

BACKGROUND AND AIMS Putative processes related to floral diversification and its relation to speciation are still largely unaccounted for in the Melastomataceae. Leandra s.str. is one of the most diverse lineages of the Neotropical Miconieae and ranks among the ten most diverse groups in the Atlantic Forest. Here, we describe the floral diversity of this lineage in a continuous framework and address several questions related to floral evolution and putative developmental and environmental constraints in its morphology. METHODS The morphological data set includes individual size measurements and shape scores (from elliptical Fourier analysis) for hypanthia, petals, stamens and styles. We evaluate whether there is evidence of correlation among these floral structures, shifts and convergent patterns, and association of these traits with elevation. KEY RESULTS Leandra s.str. flower structures present a strong phylogenetic signal and tend to be conserved among close relatives. The extremes in flower regimes seem to be quite distinct, but non-overlapping discrete flower types are not observed. Overall, the morphology of Leandra s.str. floral structures is correlated, and anther colour and inflorescence architecture correlate with flower structures. Additionally, the rates of species diversification and morphological evolution are correlated in most clades. CONCLUSIONS Although some flower regimes tend to occur in different elevational ranges, no significant association is observed. The general idea that hypanthium-ovary fusion is associated with fruit types in the Melastomataceae does not hold for Leandra s.str., where, instead, hypanthium-ovary fusion seems to be associated with anther shape. The lowest rate of flower morphological change, when compared with species diversification rates, is observed in the clade that possesses the most specialized flowers in the group. While stuck on a single general pollination system, Leandra s.str. seems to be greatly wandering around it, given the flower diversity and convergent patterns observed in this group.

Primers for Low-Copy Nuclear Genes in the Melastomataceae

Premise of the study: Low-copy nuclear gene primers were developed for phylogenetic studies across the Melastomataceae. Methods and Results: Total genomic libraries from eight species in the Melastomataceae along with one transcriptome were used for marker identification and primer design. Eight exon-primed intron-crossing markers were amplified with success in taxa of nine tribes in the Melastomataceae. The new markers were directly sequenced for eight samples of closely related species of Miconia (Chaenanthera clade) in the tribe Miconieae. The DNA sequences for the eight loci ranged from 660 to 818 aligned base pairs. Compared with four commonly used markers in other studies, the loci developed here had a higher number of variable sites than plastid spacers (7–16 vs. 26–45) and comparable variation to the ribosomal spacers (28–39). Conclusions: The novel primer pairs should be useful for a broad range of studies of systematics and evolution in the diverse Melastomataceae.