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Barboza, G. E.

Publications and source records attributed to Barboza, G. E..

3 recordsLinked to original sources

A new phylogeny and phylogenetic classification for Solanaceae

Solanaceae are a globally distributed family of considerable economic importance. Recent phylogenetic work on various clades in the family has resulted in a plethora of names at various taxonomic levels. This results in a confusing set of names applied to clades at different ranks, and to the use of informal names that are often not accepted in online resources. To solve this problem, we present here a phylogenetic classification following the PhyloCode for the Solanaceae. Traditional taxon names previously recognized at the ranks of tribe, genus, and section were maintained when associated with clades. We base our clade definitions on a newly constructed phylogeny of the family using 10 plastid and nuclear markers with a broad sampling of 1,474 species, roughly half of the diversity of the family. We complement this marker-based analysis with a phylogenomic analysis of 110 taxa (including 97 of the 102 genera in the family) using the Angiosperms353 probe set. This pair of analyses produced highly concordant phylogenies and provides strong support for the clades included in the classification. In total, we propose and define rank-free names for 38 major clades, including 16 infrageneric taxa within the mega-diverse Solanum. This rank-free system intends to promote name stability as new data become available, avoiding name changes to well-known groups.

evolutionary biology↗

Seed fossil record of Solanaceae revisited

The fossil record for Solanaceae has a complex taxonomic history, with many species originally described in the family being subsequently shown to belong in other plant families. In this work, we present an in-depth analysis of the nightshade seed fossil record, which corresponds to the largest amount of fossil material for the family despite having relatively few described taxa. We re-examined 110 fossil seeds previously assigned either to one of the six taxa or unplaced within the family. All fossils were imaged and measured for 14 discrete and continuous characters, and a subset of 22 well-preserved specimens was additionally subjected to micro-CT scanning. In parallel, we scored the same set of characters for seeds from 354 extant taxa of Solanaceae. We carried out a multivariate analysis of the combined extinct and extant dataset to visualize the placement of fossil seeds within Solanaceae seed morphospace. This analysis revealed a wide spread of fossils across morphospace, including a variety of shapes, sizes and testal wall features. For one fossil taxon (Hyoscyosperma daturoides Deanna & S.D.Sm. gen. et sp. nov.), the micro-CT images confirmed the presence of an elaiosome, otherwise only known in the family from the genus Datura L. Based on these analyses, we re-circumscribe three species and describe six new taxa (four in new genera), doubling the number of fossil seed species in the family. The broad geographic and stratigraphic distribution of these diverse taxa, from Eocene North America and Europe to Pleistocene Eurasia, support the notion that the Solanaceae is likely a family of a late Cretaceous origin that attained nearly a cosmopolitan distribution by the Eocene.

paleontology↗

Repeated evolution of a morphological novelty: a phylogenetic analysis of the inflated fruiting calyx in the Physalideae tribe (Solanaceae)

PREMISE OF THE STUDYThe evolution of novel fruit morphologies has been integral to the success of angiosperms. The inflated fruiting calyx, in which the balloon-like calyx swells to completely surround the fruit, has evolved repeatedly across angiosperms and is postulated to aid in protection and dispersal. Here we investigate the evolution of this trait in the tomatillos and their allies (Physalideae, Solanaceae), using a newly estimated phylogeny and a suite of comparative methods to infer evolutionary gains and losses.\n\nMETHODSThe Physalideae phylogeny was estimated using DNA sequences from four regions (ITS, LEAFY, trnL-F, waxy) using maximum likelihood and Bayesian Inference. Maximum likelihood model selection was used to determine the best fitting model of trait evolution. Using this model, we estimated ancestral states along with the numbers of gains and losses of fruiting calyx accrescence and inflation with Bayesian stochastic mapping. Also, phylogenetic signal in calyx morphology was examined with two metrics (parsimony score and Fritz and Purvis D).\n\nKEY RESULTSThe well resolved phylogeny points to multiple taxa in need of revision, including the eight genera that are non-monophyletic as presently circumscribed. Model fitting indicated that calyx evolution has proceeded in stepwise fashion, from non-accrescent, to accrescent, to inflated. Moreover, these transitions appear to be largely irreversible. Among the 215 sampled Physalideae, we inferred 24 gains of fruiting calyx accrescence, 24 subsequent transitions to a fully inflated calyx and only two reversals. A median of 50 shifts were estimated in total across the clade from the ancestral non-accrescent calyx. Nonetheless, fruiting calyx accrescence and inflation show strong phylogenetic signal.\n\nCONCLUSIONSOur phylogeny greatly improves the resolution of Physalideae and highlights the need for taxonomic work. The analyses of trait evolution reveal that the inflated fruiting calyx has evolved many times and that the trajectory towards this phenotype is generally stepwise and directional. These results provide a strong foundation for studying the genetic and developmental mechanisms responsible for the repeated origins of this charismatic fruit trait.

evolutionary biology↗