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El género Pisonia es primordialmente americano, se distribuye principalmente en regiones subtropicales y tropicales. En este trabajo se describe y documenta la nueva especie Pisonia calafia. Este taxon consiste de una relativamente pequeña población en la costa de la región de Los Cabos en la península de Baja California. La principal característica que diferencia a P. calafia del resto de las especies de este género es la carencia de sulcos y glándulas en el fruto. En adición a la descripción morfológica, se documenta la afinidad evolutiva del nuevo taxon con base en el análisis filogenético de la secuencia de nrITS. Las poblaciones conocidas consisten de unas pocas docenas de individuos, seriamente amenazados por el desarrollo de proyectos turísticos en la zona.

—Oenotherasect.Pachylophushas proven to be a valuable system in which to study plant-insect coevolution and the drivers of variation in floral morphology and scent. Current species circumscriptions based on morphological characteristics suggest that the section consists of five species, one of which is subdivided into five subspecies. Previous attempts to understand species (and subspecies) relationships at a molecular level have been largely unsuccessful due to high levels of incomplete lineage sorting and limited phylogenetic signal from slowly evolving gene regions. In the present study, target enrichment was used to sequence 322 conserved protein-coding nuclear genes from 50 individuals spanning the geographic range ofOenotherasect.Pachylophus, with species trees inferred using concatenation and coalescent-based methods. Our findings concur with previous research in suggesting thatO. psammophilaandO. harringtoniiare nested within a paraphyleticOenothera cespitosa. By contrast, our results show clearly that the two annual species (O. cavernaeandO. brandegeei) did not arise from theO. cespitosalineage, but rather from a common ancestor ofOenotherasect.Pachylophus. Budding speciation as a result of edaphic specialization appears to best explain the evolution of the narrow endemic speciesO. harringtoniiandO. psammophila. Complete understanding of possible introgression among subspecies ofO. cespitosawill require broader sampling across the full geographical and ecological ranges of these taxa.

Premise of research. Whole-genome duplication is often associated with the evolution of dimorphic sexual systems; however, the association is not universal, and the evolutionary pathway(s) underlyi...

Premise As Baker's law suggests, the successful colonization of oceanic islands is often associated with uniparental reproduction (self-fertility), but the high incidence of dimorphism (dioecy, gynodioecy) on islands complicates this idea. Lycium carolinianum is widespread, occurring on the North American mainland and the Hawaiian Islands. We examined Baker's ideas for mainland and island populations of L. carolinianum and examined inbreeding depression as a possible contributor to the evolution of gynodioecy on Maui. Methods Controlled crosses were conducted in two mainland populations and two populations in Hawaii. Treatments included self and cross pollination, unmanipulated controls, and autogamy/agamospermy. Alleles from the self-incompatibility S-RNase gene were isolated and compared between mainland and island populations. Given self-compatibility in Hawaii, we germinated seeds from self- and cross- treatments and estimated inbreeding depression using seven traits and a measure of cumulative fitness. Results Mainland populations of Lycium carolinianum are predominately self-incompatible with some polymorphism for self-fertility, whereas Hawaiian populations are self-compatible. Concordantly, S-RNase allelic diversity is reduced in Hawaii compared to the mainland. Hawaiian populations also exhibit significant inbreeding depression. Conclusions Self-compatibility in Hawaii and individual variation in self-fertility in mainland populations suggests that a colonization filter promoting uniparental reproduction may be acting in this system. Comparison of S-RNase variation suggests a collapse of allelic diversity and heterozygosity at the S-RNase locus in Hawaii, which likely contributed to mate limitation upon arrival to the Pacific. Inbreeding depression coupled with autonomous self-fertilization may have led to the evolution of gynodioecy on Maui.

Premise Long-distance dispersal has been important in explaining the present distributions of many plant species. Despite being infrequent, such dispersal events have considerable evolutionary consequences, because bottlenecks during colonization can result in reduced genetic diversity. We examined the phylogeographic history of Lycium carolinianum, a widespread taxon that ranges from southeastern North America to several Pacific islands, with intraspecific diversity in sexual and mating systems. Methods We used Bayesian, likelihood, and coalescent approaches with nuclear and plastid sequence data and genome-wide single nucleotide polymorphisms to reconstruct the dispersal history of this species. We also compared patterns of genetic variation in mainland and island populations using single nucleotide polymorphisms and allelic diversity at the S-RNase mating system gene. Results Lycium carolinianum is monophyletic and dispersed once from the North American mainland, colonizing the Pacific islands ca. 40,100 years ago. This dispersal was accompanied by a loss of genetic diversity in SNPs and the S-RNase locus due to a colonization bottleneck and the loss of self-incompatibility. Additionally, we documented at least two independent transitions to gynodioecy: once following the colonization of the Hawaiian Islands and loss of self-incompatibility, and a second time associated with polyploidy in the Yucatan region of Mexico. Conclusions Long-distance dispersal via fleshy, bird dispersed fruits best explains the unusually widespread distribution of L. carolinianum. The collapse of diversity at the S-RNase locus in island populations suggests that self-fertilization may have facilitated the subsequent colonization of Pacific islands following a single dispersal from mainland North America.

Lycium is the only member of tribe Lycieae (Solanoideae, Solanaceae), and it has a cosmopolitan distribution with its greatest diversity in southern South America, southern Africa, and southwestern North America. To date, there has been no attempt to synthesize and evaluate the significance of the available cytogenetical data from a phylogenetic perspective, which is the objective of this study. Firstly, new data on 27 taxa from all its range of distribution (FISH in all of them, banding in 23, Feulgen technique in 14) were provided to fill gaps in the information. The chromosome numbers of L. australe, L. humile, and L. repens were recorded for the first time. Species showed x = 12 with different ploidy levels (mostly diploid or tetraploid), small chromosomes, and symmetrical karyotypes. Lycium fremontii and L. repens were outstanding for having the highest numbers reported for the genus: 10x and 11x, respectively. North American species showed comparatively longer chromosomes. Secondly, cytogenetical traits were mapped on a phylogenetic tree, using character mapping and ancestral states reconstruction, to understand the dynamics of the evolutionary changes. The main cytotaxonomical features were included: chromosome number, presence of polyploidy, total length of the haploid chromosome set, mean chromosome length, karyotype formula, A1 and A2 asymmetry indices, percentage of heterochromatin, number of CMA+ /DAPI− NORs bands, and number and position of 5S and 18S-5.8S-26S sites. The mean chromosome length, total haploid chromosome length, number of 18S-5.8S-26S loci, number of CMA+/DAPI− NORs bands underwent comparatively few transitions compared with the ploidy level and number of 5S loci. The mapping of the characters on the phylogenetic tree showed that the most probable ancestral chromosome number was 2n = 24 with several independent polyploidization events and one pair of eachrDNA locus. The most likely ancestral condition for the genus would be: diploid, with small chromosomes, scarce heterochromatin, asynteny of rDNA loci, and one pair of both 18S-5.8S-26S and 5S loci. Fil: Stiefkens, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Las Peñas, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Levin Rachel A.. Amherst College; Estados Unidos Fil: Miller Jill S.. Amherst College; Estados Unidos Fil: Bernardello, Gabriel Luis Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Premise of the study Floral morphology is expected to evolve following the transition from cosexuality to gender dimorphism in plants, as selection through male and female function becomes dissociated. Specifically, male-biased dimorphism in flower size can arise through selection for larger flowers through male function, selection for smaller flowers through female function, or both. The evolutionary pathway to floral dimorphism can be most effectively reconstructed in species with intraspecific variation in sexual system. We examined the evolution of flower size and shape in Lycium californicum, whose populations are either gender dimorphic with male and female plants, or cosexual with hermaphroditic plants. Methods Floral morphology was characterized in populations spanning the species' complete range. For a subset of the range where cosexual and dimorphic populations are in close proximity, we compared the size and shape of flowers from female and male plants in dimorphic populations to hermaphrodites in cosexual populations, accounting for variation associated with abiotic environmental conditions. Key results The magnitude of flower size dimorphism varied across dimorphic populations. After controlling for environmental variation across cosexual and dimorphic populations, flowers on males were larger than flowers on females and hermaphrodites, whereas flower size did not differ between females and hermaphrodites. Flower shape differences were associated with mating type, sexual system, and environmental variation. Conclusions While abiotic environmental gradients shape both overall flower size and shape, male-biased flower size dimorphism in L. californicum appears to arise through selection for larger flowers in males but not smaller flowers in females.

Premise of research. Whereas most Lycium species are diploid and hermaphroditic, an association across Lycium species has been demonstrated between higher ploidy levels and gender dimorphism. Previous monographic work, in combination with a single tetraploid chromosome count, suggested that the Galapagos endemic Lycium minimum may be dimorphic. If substantiated, this would be the only documented Lycium species from South America to be dimorphic in gender expression, which is especially notable given that species diversity is highest in South America. The goals of this study are to (1) test the monophyly, characterize population-level genetic diversity, and determine the closest mainland relatives of L. minimum; (2) infer the sexual system of L. minimum; and (3) assess/verify ploidy using DNA content measurements.Methodology. Phylogenetic, morphological, and cytometric approaches were used to document evolutionary affinities, gynodioecy, and polyploidy. Phylogenetic analyses were conducted with DNA sequenc...

 Premise of the study: An association between polyploidy and gender dimorphism has been noted in several plant lineages. Whereas the majority of Lycium species are diploid and have hermaphroditic fl owers in cosexual populations, gender dimorphism (gynodioecy, dioecy) has been shown to be uniformly associated with polyploidy in previous studies. Preliminary fi eld observations suggested that some populations of Lycium carolinianum were dimorphic, providing a test of this association.  Methods: We assessed sexual systems and cytotype variation (to infer ploidy) across 17 populations of L. carolinianum . Comparison of fl owers in cosexual and dimorphic populations were used to infer changes in reproductive morphology associated with the evolution of gynodioecy.  Key results: The majority of populations were cosexual in gender expression, but dimorphism was present in the Yucat a�n and in some populations in Hawaii. Populations varied in ploidy and were either diploid or tetraploid. Floral sexual dimorphism was present in all gynodioecious populations, though the magnitude differed and was cryptic in some cases. Our results are consistent with the hypothesis that following the evolution of gynodioecy, fl owers on hermaphrodites increased in size.  Conclusions: Dimorphic sexual systems have likely evolved convergently in L. carolinianum . In contrast to previous studies, dimorphism is not perfectly associated with polyploidy. Although our sample from the Yucat a�n was both tetraploid and dimorphic, all populations in Hawaii were diploid regardless of sexual system. Ongoing phylogeographic and mating system studies will contribute to our understanding of reproductive evolution in this widespread, polymorphic species.

The identification of plastid DNA markers that provide sufficient phylogenetic resolution at the species and population levels is an important challenge for plant systematics. This is mainly due to the relatively slow rate of evolution of the plastid genome. In this study, we examine the utility of several plastid DNA regions for phylogenetic inference at low taxonomic levels in tribe Lycieae (Solanaceae). The regions employed here previously provided considerable numbers of potentially informative characters in investigations of sequence variation across the plastid genome, and one region (trnH-psbA) has been advocated for use in DNA barcoding. We sequenced nine noncoding plastid DNA regions (∼8,400 bp) for a diverse sample of Lycium species and Phrodus microphyllus (tribe Lycieae), as well as the outgroup Nolana, and included published sequences from the distant outgroup Atropa. The nine regions varied with regard to their phylogenetic utility, as measured by the numbers of variable and parsimo...

Species of Solanum subgenus Leptostemonum comprise almost one third of the genus and are distributed worldwide. Members of this group are defined by their sharp epidermal prickles; thus, they are commonly referred to as the ‘‘spiny solanums.’’ This subgenus includes a number of economically important species such as the Old World eggplants, as well as locally cultivated New World species such as the naranjilla and cocona. Given the size and importance of this group we have examined phylogenetic relationships across subgenus Leptostemonum, including a large sampling of species from previously defined species groups within the subgenus. Evolutionary relationships were inferred using DNA sequence data from two nuclear regions (ITS and the granule-bound starch synthase gene [GBSSI or waxy]) and one chloroplast spacer region (trnS-trnG). Results suggest that Solanum subgenus Leptostemonum is monophyletic when the S. wendlandii and S. nemorense species groups are excluded. We have defined 10 clades within subgenus Leptostemonum, some of which correspond to previously circumscribed species groups or sections. Most of the Old World species of subgenus Leptostemonumbelong to a single species-rich clade. Sharp prickles and/or stellate hairs evolved more than once in Solanum, and floral heterandry originated multiple times within the ‘‘spiny solanums.’’ waxy.

The "spiny solanums," Solanum subgenus Leptostemonum (Solanaceae), comprise a large lineage with over 350 species and include the cultivated eggplant, Solanum melongena. Despite the importance of this subgenus, phylogenetic relationships among these taxa are currently unclear. The present research contributes to this understanding while focusing on Solanum section Acanthophora, a group of ca. 19 species defined by the presence of simple hairs, rather than the stellate hairs common across the rest of subgenus Leptostemonum. In this study we inferred phylogenetic relationships among 29 Solanum taxa, including 14 species of section Acanthophora, using DNA sequence data from two nuclear regions (ITS and the granule-bound starch synthase gene [GBSSI or waxy]) and two chloroplast regions (trnT-trnF and trnS-trnG). This combination of gene regions resulted in a well resolved phylogenetic hypothesis, with results strongly suggesting that Solanum sect. Acanthophora is not monophyletic, although the majority of taxa comprise a monophyletic lineage that is sister to Solanum section Lasiocarpa. Of the four gene regions, waxy was especially useful for phylogenetic inference, with both a high percentage of parsimony-informative sites as well as a low level of homoplasy. Further studies in progress will help elucidate relationships of sect. Acanthophora with respect to other members of subgenus Leptostemonum.

GC-MS analyses of nocturnal and diurnal floral volatiles from nine tobacco species (Nicotiana; Solanaceae) resulted in the identification of 125 volatiles, including mono- and sesquiterpenoids, benzenoid and aliphatic alcohols, aldehydes and esters. Fragrance chemistry was species-specific during nocturnal emissions, whereas odors emitted diurnally were less distinct. All species emitted greater amounts of fragrance at night, regardless of pollinator affinity. However, these species differed markedly in odor complexity and emission rates, even among close relatives. Species-specific differences in emission rates per flower and per unit fresh or dry flower mass were significantly correlated; fragrance differences between species were not greatly affected by different forms of standardization. Flowers of hawkmoth-pollinated species emitted nitrogenous aldoximes and benzenoid esters on nocturnal rhythms. Four Nicotiana species in section Alatae sensu strictu have flowers that emit large amounts of 1,8 cineole, with smaller amounts of monoterpene hydrocarbons and alpha-terpineol on a nocturnal rhythm. This pattern suggests the activity of a single biosynthetic enzyme (1,8 cineole synthase) with major and minor products; however, several terpene synthase enzymes could contribute to total monoterpene emissions. Our analyses, combined with other studies of tobacco volatiles, suggest that phenotypic fragrance variation in Nicotiana is shaped by pollinator- and herbivore-mediated selection, biosynthetic pathway dynamics and shared evolutionary history.

Despite intensive morphological and molecular studies of Onagraceae, relationships within the family are not fully understood. One drawback of previous analyses is limited sampling within the large tribe Onagreae. In addition, the monophyly of two species-rich genera in Onagreae, Camissonia and Oenothera, has never been adequately tested. To understand relationships within Onagraceae, test the monophyly of these two genera, and ascertain the affinities of the newly discovered genus Megacorax, we conducted parsimony and maximum likelihood analyses with rbcL and ndhF sequence data for 24 taxa representing all 17 Onagraceae genera and two outgroup Lythraceae. Results strongly support a monophyletic Onagraceae, with Ludwigia as the basal lineage and a sister-taxon relationship between Megacorax and Lopezia. Gongylocarpus is supported as sister to Epilobieae plus the rest of Onagreae, although relationships within the latter clade have limited resolution. Thus, we advocate placement of Gongylocarpus in a monogeneric tribe, Gongylocarpeae. Most relationships within Onagreae are weakly resolved, suggesting a rapid diversification of this group in western North America. Neither Camissonia nor Oenothera appears to be monophyletic; however, increased taxon sampling is needed to clarify those relationships. Morphological characters generally agree with the molecular data, providing further support for relationships.

We infer phylogenetic relationships among Lycium, Grabowskia, and the monotypic Phrodus microphyllus, using DNA sequence data from the nuclear granule-bound starch synthase gene (GBSSI, waxy) and the chloroplast region trnT-trnF. This is the first comprehensive molecular phylogenetic study of tribe Lycieae (Solanaceae). In addition to providing an understanding of evolutionary relationships, we use the phylogenetic hypotheses to frame our studies of breeding system transitions, floral and fruit evolution, and biogeographical patterns within Lycieae. Whereas Lycium is distributed worldwide, Phrodus and the majority of Grabowskia species are restricted to South America. Tribe Lycieae is strongly supported as monophyletic, but Lycium likely includes both Grabowskia and Phrodus. Results also suggest a single dispersal event from the Americas to the Old World, and frequent dispersal between North and South America. The diversity of fruit types in Lycieae is discussed in light of dispersal patterns and recent work on fruit evolution across Solanaceae. Dimorphic gender expression has been studied previously within Lycium, and results indicate that transitions in sexual expression are convergent, occurring multiple times in North America (a revised estimate from previous studies) and southern Africa.

We present results of dynamic head-space collections and GC–MS analyses of floral and vegetative fragrances for 20 species in three genera of Nyctaginaceae: Acleisanthes, Mirabilis and Selinocarpus. Most of the species included in this study are either hawkmoth or noctuid moth-pollinated. A wide variety of compounds were observed, including mono- and sesquiterpenoids, aromatics (both benzenoids and phenylpropanoids), aliphatic compounds, lactones, and nitrogen-bearing compounds. Intraspecific variation in fragrance profiles was significantly lower than interspecific variation. Each species had a unique blend of volatiles, and the fragrance of many species contained species-specific compounds. The fragrance profiles presented here are generally consistent with previous studies of fragrance in a variety of moth-pollinated angiosperms.

Recent molecular and morphological studies suggest that neither Acleisanthes nor Selinocarpus (Nyctaginaceae) are monophyletic as currently circumscribed. Further, these data provide no basis for continued recognition of the monotypic genus Ammocodon as separate from these other two genera. Therefore, all 8 Selinocarpus species and the monospecific Ammocodon are transferred to Acleisanthes; 3 additional Selinocarpus species are reduced to synonymy. The genus Acleisanthes is now composed of 16 species, distributed primarily in the Chihuahuan Desert of North America. Diagnostic features of Acleisanthes include an herbaceous or woody perennial habit in arid environments, and the presence of both cleistogamous and chasmogamous flowers often simultaneously on an individual plant. Further, flowers are usually axillary and subtended by 1 to 4 subulate bracts, with chasmogamous flowers frequently white or yellow and funnelform to salverform.

Nyctaginaceae are a small family of mainly New World tropical and subtropical trees, shrubs, and herbs. To date phylogenetic relationships within the family have not been examined. This study provides the first phylogenetic hypothesis of relationships within Nyctaginaceae tribe Nyctagineae based on sequence data from both nuclear (ITS) and chloroplast (accD 5‘coding region and intergenic region between the rbcL and accD genes). Morphological characters are also discussed as they relate to the phylogeny inferred using molecular data. Results suggest that neither Acleisanthes nor Selinocarpus is monophyletic but that together they comprise a monophyletic lineage. The genus Mirabilis is strongly supported as monophyletic, but the monophyly of two of its sections is suspect. Morphology generally agrees with the molecular data and in some instances reinforces clades weakly supported by nuclear and chloroplast data. Further sampling will help clarify relationships of these genera within Nyctaginaceae. ...