A revision of the South American species of the Morelloid clade (Solanum L., Solanaceae).

The Morelloid clade, also known as the black nightshades or "Maurella" (Morella), is one of the 10 major clades within the mega-diverse genus Solanum L. The clade is most diverse in the central to southern Andes, but species occur around the tropics and subtropics, some extending well into the temperate zone. Plants of the group vary from herbs to short-lived perennials to perennial shrubs that are distinctly woody at the base, they have small mostly white or purplish white flowers and small juicy berries. Due to the complex morphological variation and weedy nature of these plants, coupled with the large number of published synonyms (especially for European taxa), our understanding of species limits and diversity in the Morelloid clade has lagged behind that of other clades in Solanum. Here we provide the last in a three-part series of monographic treatments of the morelloid solanums (see PhytoKeys Vols. 106, 125), treating the 62 species occurring in South America. This region is by far the most diverse in the clade, both in terms of species number and morphological diversity. We provide complete synonymy, nomenclatural details, including lecto- and neotypifications where needed, common names and uses, morphological descriptions, illustrations to aid identification both in herbaria and in the field, and distribution maps for all native, non-cultivated species. We include a key to all species, a synoptic character list for the species treated here and links to synoptic online keys for all species of the Morelloid clade. Preliminary conservation assessments following IUCN guidelines are also provided for all native species.

Fossil berries reveal global radiation of the nightshade family by the early Cenozoic.

Fossil discoveries can transform our understanding of plant diversification over time and space. Recently described fossils in many plant families have pushed their known records farther back in time, pointing to alternative scenarios for their origin and spread. Here, we describe two new Eocene fossil berries of the nightshade family (Solanaceae) from the Esmeraldas Formation in Colombia and the Green River Formation in Colorado (USA). The placement of the fossils was assessed using clustering and parsimony analyses based on 10 discrete and five continuous characters, which were also scored in 291 extant taxa. The Colombian fossil grouped with members of the tomatillo subtribe, and the Coloradan fossil aligned with the chili pepper tribe. Along with two previously reported early Eocene fossils from the tomatillo genus, these findings indicate that Solanaceae were distributed at least from southern South America to northwestern North America by the early Eocene. Together with two other recently discovered Eocene berries, these fossils demonstrate that the diverse berry clade and, in turn, the entire nightshade family, is much older and was much more widespread in the past than previously thought.

Diversification of chiles (Capsicum, Solanaceae) through time and space: New insights from genome-wide RAD-seq data.

Capsicum L. encompasses 43 American species, including the five domesticated worldwide consumed sweet and hot chiles. This study presents new, updated and age-calibrated phylogenetic hypothesis on the genus evolution incorporating nearly all currently accepted Capsicum species. A new model of spatial diversification of Capsicum is proposed based on analyses of several thousands of genome-wide RAD-seq derived SNPs. Maximum likelihood approaches were used to reconstruct phylogenies and to estimate dates of all major splits. Ancestral ranges were inferred and diversification events were modeled in a time frame using a Bayesian approach. Nine clades corresponding to genetically and (mostly) geographically well-defined lineages, which diversified starting around mid-upper Miocene, were recovered with strong support. The Northern and Central Andes were inferred to represent the most likely ancestral range of the genus Capsicum. A few early vicariant and dispersal events were estimated to have driven the geographic divergence of the main Capsicum clades. Each lineage was inferred to have diversified within a distinct region of South America and expanded geographically to different extent. Extant species diversification was inferred to have begun at the beginning of Pliocene and continued through the Pleistocene. The Central Andes, represented mainly by the territory of present-day Bolivia, were proposed to play a central role in the diversification of lineages comprising domesticated capsicums and their wild allies. The genome-wide approach allowed for high resolution and support of deep phylogenetic nodes providing novel insights into the affinities of major lineages and clades as well as on the geographic expansion of Capsicum. This study provides the first dated evolutionary history of the genus encompassing most of the chile species diversity.

Transcription Factors Evolve Faster Than Their Structural Gene Targets in the Flavonoid Pigment Pathway.

Dissecting the relationship between gene function and substitution rates is key to understanding genome-wide patterns of molecular evolution. Biochemical pathways provide powerful systems for investigating this relationship because the functional role of each gene is often well characterized. Here, we investigate the evolution of the flavonoid pigment pathway in the colorful Petunieae clade of the tomato family (Solanaceae). This pathway is broadly conserved in plants, both in terms of its structural elements and its MYB, basic helix-loop-helix, and WD40 transcriptional regulators, and its function has been extensively studied, particularly in model species of petunia. We built a phylotranscriptomic data set for 69 species of Petunieae to infer patterns of molecular evolution across pathway genes and across lineages. We found that transcription factors exhibit faster rates of molecular evolution (dN/dS) than their targets, with the highly specialized MYB genes evolving fastest. Using the largest comparative data set to date, we recovered little support for the hypothesis that upstream enzymes evolve slower than those occupying more downstream positions, although expression levels do predict molecular evolutionary rates. Although shifts in floral pigmentation were only weakly related to changes affecting coding regions, we found a strong relationship with the presence/absence patterns of MYB transcripts. Intensely pigmented species express all three main MYB anthocyanin activators in petals, whereas pale or white species express few or none. Our findings reinforce the notion that pathway regulators have a dynamic history, involving higher rates of molecular evolution than structural components, along with frequent changes in expression during color transitions.

Monograph of wild and cultivated chili peppers (Capsicum L., Solanaceae).

Capsicum L. (tribe Capsiceae, Solanaceae) is an American genus distributed ranging from the southern United States of America to central Argentina and Brazil. The genus includes chili peppers, bell peppers, ajíes, habaneros, jalapeños, ulupicas and pimientos, well known for their economic importance around the globe. Within the Solanaceae, the genus can be recognised by its shrubby habit, actinomorphic flowers, distinctive truncate calyx with or without appendages, anthers opening by longitudinal slits, nectaries at the base of the ovary and the variously coloured and usually pungent fruits. The highest diversity of this genus is located along the northern and central Andes. Although Capsicum has been extensively studied and great advances have been made in the understanding of its taxonomy and the relationships amongst species, there is no monographic treatment of the genus as a whole. Based on morphological and molecular evidence studied from field and herbarium specimens, we present here a comprehensive taxonomic treatment for the genus, including updated information about morphology, anatomy, karyology, phylogeny and distribution. We recognise 43 species and five varieties, including C.mirum Barboza, sp. nov. from São Paulo State, Brazil and a new combination C.muticum (Sendtn.) Barboza, comb. nov.; five of these taxa are cultivated worldwide (C.annuumL.var.annuum, C.baccatumL.var.pendulum (Willd.) Eshbaugh, C.baccatumL.var.umbilicatum (Vell.) Hunz. & Barboza, C.chinense Jacq. and C.frutescens L.). Nomenclatural revision of the 265 names attributed to chili peppers resulted in 89 new lectotypifications and five new neotypifications. Identification keys and detailed descriptions, maps and illustrations for all taxa are provided.

Living in extreme environments: distribution of Lyciumhumile (Solanaceae), an endemic halophyte from the Altiplano-Puna region, South America.

Very few Solanaceae species are able to grow in saline soils; one of them is Lyciumhumile. This species is endemic to the Altiplano-Puna region (Central Andes, South America) where there are multiple extreme environmental conditions such as hypersaline soils. Here we present an updated description and distribution of L.humile including its new record for Bolivia at the edges of "Salar de Uyuni", the largest salt flat in the world; we discuss its ecological role in saline environments by analyzing soil salinity and cover-abundance values ​​of the studied sites. According to IUCN criteria, we recommend a category of Least Concern for L.humile, but the growing development of lithium mining in saline environments of the Altiplano-Puna region may potentially threaten exclusive communities.

New insights into the salt tolerance of the extreme halophytic species Lycium humile (Lycieae, Solanaceae).

Knowledge about Solanaceae species naturally adapted to salinity is scarce, despite the fact that a considerable number of Solanaceae has been reported growing in saline environments. Lycium humile Phil. inhabits extreme saline soils in the Altiplano-Puna region (Central Andes, South America) and represents a promising experimental model to study salt tolerance in Solanaceae plants. Seeds, leaves and roots were collected from a saline environment (Salar del Diablo, Argentina). Seeds were scarified and 30 days after germination salt treatments were applied by adding NaCl salt pulses (up to 750 or 1000 mM). Different growth parameters were evaluated, and leaf spectral reflectance, endogenous phytohormone levels, antioxidant capacity, proline and elemental content, and morpho-anatomical characteristics in L. humile under salinity were analyzed both in controlled and natural conditions. The multiple salt tolerance mechanisms found in this species are mainly the accumulation of the phytohormone abscisic acid, the increase of the antioxidant capacity and proline content, together with the development of a large leaf water-storage parenchyma that allows Na+ accumulation and an efficient osmotic adjustment. Lycium humile is probably one of the most salt-tolerant Solanaceae species in the world, and, in controlled conditions, can effectively grow at high NaCl concentrations (at least, up to 750 mM NaCl) but also, in the absence of salts in the medium. Therefore, we propose that natural distribution of L. humile is more related to water availability, as a limiting factor of growth in Altiplano-Puna saline habitats, than to high salt concentrations in the soils.

An amazing new Capsicum (Solanaceae) species from the Andean-Amazonian Piedmont.

Capsicum regale Barboza & Bohs, sp. nov., a new species from the tropical wet forests of the eastern Andean slopes (Colombia, Ecuador, and Peru) is described and illustrated. This new species belongs to the Andean clade (all species 2n = 26) of Capsicum and is similar to C. longifolium Barboza & S.Leiva in its glabrescence, calyx morphology, and corolla and seed color but differs in its membranous and elliptic leaves, fleshy calyces, deeper stellate corollas, longer filaments, longer and purple fruiting pedicels, purple berries, and larger seeds. Its chromosome number was counted (2n = 26), a preliminary assessment of conservation status is given and discussed, and an updated identification key to the species of the Andean clade is provided.

The Morelloid clade of Solanum L. (Solanaceae) in Argentina: nomenclatural changes, three new species and an updated key to all taxa.

Since the publication of the Solanaceae treatment in "Flora Argentina" in 2013 exploration in the country and resolution of outstanding nomenclatural and circumscription issues has resulted in a number of changes to the species of the Morelloid clade of Solanum L. (Solanaceae) for Argentina. Here we describe three new species: Solanum hunzikeri Chiarini & Cantero, sp. nov., from wet high elevation areas in Argentina (Catamarca, Salta and Tucumán) and Bolivia (Chuquisaca and Tarija), S. marmoratum Barboza & S. Knapp, sp. nov., from central Argentina in Catamarca, La Pampa, La Rioja, San Juan and San Luis, and S. tiinae Barboza & S. Knapp, sp. nov., from the mountains of Jujuy, La Rioja, Salta and Tucumán. We provide descriptions, illustrations and distribution maps for all new taxa. A table of nomenclatural changes and additional taxa now known to occur in Argentina summarizes additions and changes since the "Flora Argentina". We also provide an updated key, including all new taxa for the country, to facilitate identification and further exploration.

Solanaceae diversity in South America and its distribution in Argentina.

Solanaceae is one of the most diverse families in the Americas, particularly in Argentina where it represents the fourth family in terms of species number. Although checklists for most South American countries have been published, some are outdated and there has been no analysis of Solanaceae diversity at country level. We present an updated summary of Solanaceae diversity in South America, an analysis of its distribution in Argentina, and preliminary conservation assessments for all species endemic to Argentina. Regression analyses were used for evaluating the ratio between taxa/area and endemic/total species, multivariate ordering methods were used to analyze the relationships between Argentine ecoregions, and the IUCN criteria were applied for conservation assessments. Results show that Solanaceae comprises 1611 species in South America. The highest diversity is in Peru, which, together with Ecuador, possesses more diversity than expected for the area; Chile and Brazil have the greatest percentage of endemic species. In Argentina, the Chaco ecoregion hosts the highest number of taxa, but largest number of endemic species is found in the Monte ecoregion. According to the IUCN criteria, 28 endemic species from Argentina are considered threatened. We discuss South American countries and Argentine ecoregions in terms of conservation priorities.

Withanolides from the genus Exodeconus (Solanaceae). Chemotaxonomical considerations.

Five Exodeconus species were phytochemically analyzed. From the aerial parts of E. pusillus, the 7α,27-dihydroxy-1-oxo-22R-witha-2,5,24-trienolide and three other previously unreported normal-type withanolides were isolated. All the studied species had normal type and/or ring-D aromatic withanolides, and some had already been isolated from other Solanaceae genera, and therefore, these compounds are not chemotaxonomic markers at the generic level. The chemical composition of an undescribed Exodeconus species analyzed here supports the designation of this taxon as a new entity. The integral chemical profile of Exodeconus can be evaluated for its taxonomic implication when a more robust phylogeny of Solanaceae is available that allows the phylogenetic relationships with its closest genera to be clarified.

Capsicum carassense (Solanaceae), a new species from the Brazilian Atlantic Forest.

Capsicum carassense Barboza & Bianchetti sp. nov., a species from mid-elevation of the Atlantic Forest (Minas Gerais, Brazil) is described and illustrated. This endemic new species is distinguished from the most similar C. mirabile Mart. by its moderate to dense general pubescence, narrowly elliptic leaves and larger calyx appendages and corollas. A key for the native Brazilian species of Capsicum growing in the state of Minas Gerais is also provided.

Synthetic Lethal Activity of Benzophenanthridine Alkaloids From Zanthoxylum coco Against BRCA1-Deficient Cancer Cells.

Several plants from South America show strong antitumoral properties based on anti-proliferative and/or pro-apoptotic activities. In this work we aimed to identify selective cytotoxic compounds that target BRCA1-deficient cancer cells by Synthetic Lethality (SL) induction. Using a high-throughput screening technology developed in our laboratory, we analyzed a collection of extracts from 46 native plant species from Argentina using a wide dose-response scheme. A highly selective SL-induction capacity was found in an alkaloidal extract from Zanthoxylum coco (Fam. Rutaceae). Bio-guided fractionation coupled to HPLC led to the identification of active benzophenanthridine alkaloids. The most potent SL activity was found with the compound oxynitidine, which showed a remarkably low relative abundance in the active fractions. Further validation experiments were performed using the commercially available and closely related analog nitidine, which showed SL-induction activity against various BRCA1-deficient cell lines with different genetic backgrounds, even in the nanomolar range. Exploration of the underlying mechanism of action using BRCA1-KO cells revealed AKT and topoisomerases as the potential targets responsible of nitidine-triggered SL-induction. Taken together, our findings expose an unforeseen therapeutic activity of alkaloids from Zanthoxylum-spp. that position them as novel lead molecules for drug discovery.

A revision of the Morelloid Clade of Solanum L. (Solanaceae) in North and Central America and the Caribbean.

The Morelloid Clade, also known as the black nightshades or "Maurella" (Morella), is one of the 10 major clades within the mega-diverse genus Solanum L. The clade is most species rich in the central to southern Andes, but species occur around the tropics and subtropics, some extending well into the temperate zone. Plants of the group are herbaceous or short-lived perennials, with small white or purplish white flowers, and small juicy berries. Due to the complex morphological variation and weedy nature of these plants, coupled with the large number of published synonyms (especially for European taxa), our understanding of species limits and diversity in the Morelloid Clade has lagged behind that of other major groups in Solanum. Here we provide the second in a three-part series of revisions of the morelloid solanums treating the species occurring in North and Central America and the Caribbean (for the Old World see "PhytoKeys 106", the third part will treat species of South America). Synonymy, morphological descriptions, distribution maps, and common names and uses are provided for all 18 species occurring in this region. We treat 10 of these species as native, and eight as putatively naturalised, introduced and/or invasive in the region. We provide complete descriptions with nomenclatural details, including lecto- and neotypifications, for all species. Keys to all species occurring in the whole region and for each area within it (i.e., North America, Central America and Mexico, and the islands of the Caribbean), illustrations to aid identification both in herbaria and in the field, and distribution maps are provided. Preliminary conservation assessments are provided for all species. Details of all specimens examined are provided in three Supplementary materials sections.

Historical biogeography of the fern genus Polystichum (Dryopteridaceae) in Austral South America.

A group of seven endemic Polystichum species inhabit Patagonia, the southern region of South America. To date, evolutionary relationships of these Austral South American Polystichum remain unknown. The biota of the Southern Andes appears to be more closely related to the temperate Australasian species than to northern South American ones. Differences in morphological characters suggested that Austral South American Polystichum follows that biogeographical pattern, not being closely related to their congeners in the Northern and Central Andes. We sought to reveal the evolutionary relationships, estimate the divergence times and reconstruct both ancestral areas and ancestral ploidy levels of Austral South America Polystichum. Phylogenetic relationships were estimated using maximum likelihood and Bayesian approaches. The seven Austral South American species plus 31 Polystichum species spanning all other major biogeographic regions were sampled for three DNA markers. Divergence times were estimated in BEAST and Bayesian binary Markov chain Monte Carlo reconstruction was applied in order to infer ancestral areas. The evolution of ploidy was reconstructed on the maximum clade credibility tree, using stochastic character mapping. Austral South American Polystichum was recovered as monophyletic. The earliest divergence reconstructed within the Austral South American Clade was that of Polystichum andinum; subsequently two other lineages diverged comprising the remaining Austral South American species. The Austral South American lineage is not closely allied to North and Central Andes congeners. Long-distance dispersal of an ancestral tetraploid from Australasia during the late Miocene is the most likely explanation for the origin of Patagonian Polystichum. Then, Pliocene and Pleistocene orogenic and climatic changes may have shaped its diversification in Patagonia.

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

PREMISE OF THE STUDY: The 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. We investigated the evolution of this trait in the tomatillos and their allies (Physalideae, Solanaceae). METHODS: The Physalideae phylogeny was estimated using four regions (ITS, LEAFY, trnL-F, waxy) with maximum likelihood (ML) and Bayesian inference. Under the best-fitting ML model of trait evolution, 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's D). KEY RESULTS: Based on our well-resolved and densely sampled phylogeny, we infer that calyx evolution has proceeded in a stepwise and directional fashion, from non-accrescent to accrescent to inflated. In total, we inferred 24 gains of accrescence, 24 subsequent transitions to a fully inflated calyx, and only two reversals. Despite this lability, fruiting calyx accrescence and inflation showed strong phylogenetic signal. CONCLUSIONS: Our phylogeny greatly improves the resolution of Physalideae and highlights the need for taxonomic work. The comparative analyses reveal that the inflated fruiting calyx has evolved many times and that the trajectory toward this phenotype is generally stepwise and irreversible. These results provide a strong foundation for studying the genetic and developmental mechanisms responsible for the repeated origins of this charismatic fruit trait.

Four new species of Capsicum (Solanaceae) from the tropical Andes and an update on the phylogeny of the genus.

Four new species of Capsicum (Capsiceae, Solanaceae) from Andean tropical forests in South America are described. Capsicum benoistii Hunz. ex Barboza sp. nov. (incertae sedis) is endemic to a restricted area in south-central Ecuador and is most similar to the more widespread C. geminifolium (Dammer) Hunz. (Colombia, Ecuador, and Peru). Capsicum piuranum Barboza & S. Leiva sp. nov. (Andean clade) is found in northern Peru (Department Piura) and is morphologically most similar to C. caballeroi M. Nee of the Bolivian yungas (Departments Santa Cruz and Cochabamba) but closely related to C. geminifolium and C. lycianthoides Bitter. Capsicum longifolium Barboza & S. Leiva sp. nov. (Andean clade) occurs from northern Peru (Departments Amazonas, Cajamarca, and Piura) to southern Ecuador (Province Zamora-Chinchipe), and is morphologically most similar to C. dimorphum (Miers) Kuntze (Colombia, Ecuador, and Peru). Capsicum neei Barboza & X. Reyes sp. nov. (Bolivian clade) is endemic to southeastern Bolivia (Departments Chuquisaca and Santa Cruz) in the Boliviano-Tucumano Forest, is morphologically most similar to another Bolivian endemic species C. minutiflorum Rusby (Hunz.), and is closely related to C. caballeroi. Complete descriptions, illustrations, distributions and conservation assessments of all new species are given. Chromosome numbers for C. piuranum and C. longifolium are also provided. Three of the new species were included in a new phylogenetic analysis for Capsicum; their positions were strongly resolved within clades previously recognized in the genus.

A revision of the Old World Black Nightshades (Morelloid clade of Solanum L., Solanaceae).

The Morelloid clade, also known as the black nightshades or "Maurella" (Morella), is one of the 10 major clades within Solanum L. The pantropical clade consists of 75 currently recognised non-spiny herbaceous and suffrutescent species with simple or branched hairs with or without glandular tips, with a centre of distribution in the tropical Andes. A secondary centre of diversity is found in Africa, where a set of mainly polyploid taxa occur. A yet smaller set of species is found in Australasia and Europe, including Solanum nigrum L., the type of the genus Solanum. Due to the large number of published synonyms, combined with complex morphological variation, our understanding of species limits and diversity in the Morelloid clade has remained poor despite detailed morphological studies carried out in conjunction with breeding experiments. Here we provide the first taxonomic overview since the 19th century of the entire group in the Old World, including Africa, Asia, Australia, Europe and islands of the Pacific. Complete synonymy, morphological descriptions, distribution maps and common names and uses are provided for all 19 species occurring outside the Americas (i.e. Africa, Asia, Australia, Europe and islands of the Pacific). We treat 12 species native to the Old World, as well as 7 taxa that are putatively introduced and/or invasive in the region. The current knowledge of the origin of the polyploid species is summarised. A key to all of the species occurring in the Old World is provided, together with line drawings and colour figures to aid identification both in herbaria and in the field. Preliminary conservation assessments are provided for all species.

Phylogenetic relationships of Deprea: New insights into the evolutionary history of physaloid groups.

Deprea is the genus with the second highest species richness in tribe Physalideae (Solanaceae) and comprises 50 species that are mainly distributed in the Andes of South America. The taxonomy of Deprea has been unstable after controversial hypotheses about its position and circumscription. Additionally, biogeographical inferences are only based on observations of the restricted area of distribution of some species and no ancestral area estimation have been performed. Here, we present a phylogenetic analysis and an ancestral area reconstruction of Deprea in order to establish its circumscription, resolve its position within Physalideae, and reconstruct its biogeographical history. Phylogenetic analyses were conducted using Maximum Likelihood and Bayesian approaches. Forty-three Deprea species and 26 related taxa were sampled for three DNA markers (psbA-trnH, ITS, and waxy). A Bayesian binary MCMC model was applied in order to infer ancestral areas. Deprea is resolved as a strongly supported monophyletic group according to its current circumscription and is placed within subtribe Withaninae of Physalideae. The phylogenetic relationships enabled us to solve taxonomic problems including the rejection and acceptance of previous synonyms. The most probable ancestral area for Deprea is the Northern Andes of South America and the Amotape-Huancabamba zone. Our phylogeny provides increased resolution and support for the current position and circumscription of Deprea. Better resolution of interspecific relationships was also obtained, although some affinities remain unclear. The phylogenetic and ancestral area reconstructions provide a framework for addressing taxonomic problems and investigating new evolutionary questions.

Phytochemical Study of the Genus Salpichroa (Solanaceae), Chemotaxonomic Considerations, and Biological Evaluation in Prostate and Breast Cancer Cells.

Twelve Salpichroa taxa have been phytochemically analyzed. From the aerial parts of S. scandens, four known salpichrolides A, C, I, S, and an unreported withanolide named salpichrolide V (1), were isolated. In S. dependens, S. gayi, S. glandulosa subsp. glandulosa, S. glandulosa subps. weddellii, S. leucantha, S. micrantha, S. microloba, S. proboscidea, S. ramosissima, S. tristis var. tristis, and S. weberbauerii, no withanolides were found. The chemical content of ca. 85% of the Salpichroa taxa is in agreement with molecular studies, which suggest that Salpichroa and Jaborosa, a genus considered morphologically close to Salpichroa, are distant in the systematic of the Solanoideae subfamily. Moreover, the in vitro cytotoxic activity of a set of natural salpichrolides and derivatives was examined against two prostate carcinoma cell lines (PC3 and LNCaP) and two human breast cancer cell lines (MCF-7 and T47D). Several compounds showed moderate activity (IC50  = 64.91 - 29.97 µm).