First Bignoniaceae liana from the Miocene of South America and its evolutionary significance.

PREMISE: Two Bignoniaceae stems with the distinctive anatomy of a liana are described from the Miocene of South America. They are the first fossil evidence of climbing habit in Bignoniaceae. METHODS: The fossil lianas are siliceous permineralizations. Transverse, tangential, and radial thin sections of the woods were prepared for study using standard petrographic techniques and observed under both light and scanning electron microscopy. RESULTS: The stems consist of wood and presumably bark (peripheral tissues). They exhibit phloem wedges, a cambial variant associated with the climbing habit in Bignoniaceae. The wood is diffuse-porous; solitary and in radial multiples vessels; alternated intervessel pitting; ray-vessel pitting with distinct borders; simple perforation plates; rays 1-3 seriate, composed of procumbent cells or body ray cells procumbent with one or two-row of upright or square marginal cells; fibers septate and non-septate, with simple to minutely bordered pits; axial parenchyma scanty paratracheal, vasicentric, septate; perforated ray cells; prismatic crystals in rays, and rays and fibers irregularly storied. The fossil stems are related to extant Dolichandra unguis-cati (L.) Miers. CONCLUSIONS: The fossils represent a new taxon, Dolichandra pacei sp. nov., which confirms the presence of a neotropical Bignoniaceae liana from the Miocene and provides the first and oldest evidence of the climbing habit in the family. Paleobotanical studies in the Mariño Formation, with the record of Bignoniaceae and Verbenaceae, and phylogenetic and biogeographical studies have great importance to understand plant evolution and diversification in South American Andes.

Interspecific anatomical differences result in similar highly flexible stems in Bignoniaceae lianas.

PREMISE: Lianas are intriguing forest components in the tropics worldwide. They are characterized by thin and flexible stems, which have been related to a unique stem anatomy. Here, we hypothesized that the anatomical diversity of lianas, varying in shapes, proportions, and dimensions of tissues and cell types, would result in different stem bending stiffnesses across species. To test this hypothesis, we chose four abundant liana species of central Amazonia belonging to the monophyletic tribe Bignonieae (Bignoniaceae) and compared their basal stems for their anatomical architectures and bending properties. METHODS: Measurements of anatomical architecture and bending stiffness (structural Young's modulus) included light microscopy observations and three-point bending tests, which were performed on basal stems of eight individuals from four Bignonieae species. All analyses, including comparisons among species and relationships between stem stiffness and anatomical architecture, were performed using linear models. RESULTS: Although the anatomical architecture of each species consists of different qualitative and quantitative combinations of both tissues and cell types in basal stems, all species analyzed showed similarly lower bending stiffnesses. This similarity was shown to be directly related to high bark contribution to the second moment of area, vessel area and ray width. CONCLUSIONS: Similar values of stem bending stiffness were encountered in four liana species analyzed despite their variable anatomical architectures. This pattern provides new evidence of how different quantitative combinations of tissue and cell types in the basal stems of lianas can generate similarly low levels of stiffness in a group of closely related species.

Complete chloroplast genome sequences contribute to plant species delimitation: A case study of the Anemopaegma species complex.

PREMISE OF THE STUDY: Bignoniaceae is an important component of neotropical forests and a model for evolutionary and biogeographical studies. A previous combination of molecular markers and morphological traits improved the phylogeny of the group. Here we demonstrate the value of next-generation sequencing (NGS) to assemble the chloroplast genome of eight Anemopaegma species and solve taxonomic problems. METHODS: Three NGS platforms were used to sequence total DNA of Anemopaegma species. After genome assembly and annotation, we compared chloroplast genomes within Anemopaegma, with other Lamiales species, and the evolutionary rates of protein-coding genes using Tanaecium tetragonolobum as the outgroup. Phylogenetic analyses of Anemopaegma with different data sets were performed. KEY RESULTS: Chloroplast genomes of Anemopaegma species ranged from 167,413 bp in A. foetidum to 168,987 bp in A. acutifolium ("typical" form). They exhibited a characteristic quadripartite structure with a large single-copy region (75,070-75,761 bp), a small single-copy region (12,766-12,817 bp) and a pair of inverted repeat regions (IRs) (39,480-40,481) encoding an identical set of 112 genes. An inversion of a fragment with ca. 8 kb, located in the IRs and containing the genes trnI-AAU, ycf2, and trnL-CAA, was observed in these chloroplast genomes when compared with those of other Lamiales. CONCLUSIONS: Anemopaegma species have the largest genomes within the Lamiales possibly due to the large amount of repetitive sequences and IR expansion. Variation was higher in coding regions than in noncoding regions, and some genes were identified as markers for differentiation between species. The use of the entire chloroplast genome gave better phylogenetic resolution of the taxonomic groups. We found that two forms of A. acutifolium result from different maternal lineages.

A genomic approach for isolating chloroplast microsatellite markers for Pachyptera kerere (Bignoniaceae).

PREMISE OF THE STUDY: In this study, we developed chloroplast microsatellite markers (cpSSRs) for Pachyptera kerere (Bignoniaceae) to investigate the population structure and genetic diversity of this species. METHODS AND RESULTS: We used Illumina HiSeq data to reconstruct the chloroplast genome of P. kerere by a combination of de novo and reference-guided assembly. We then used the chloroplast genome to develop a set of cpSSRs from intergenic regions. Overall, 24 primer pairs were designed, 21 of which amplified successfully and were polymorphic, presenting three to nine alleles per locus. The unbiased haploid diversity per locus varied from 0.207 (Pac28) to 0.817 (Pac04). All but one locus amplified for all other taxa of Pachyptera. CONCLUSIONS: The markers reported here will serve as a basis for studies to assess the genetic structure and phylogeographic history of Pachyptera.

Structure and distribution of glandular trichomes in three species of Bignoniaceae / Estrutura e distribuição de tricomas glandulares em três espécies da família Bignoniaceae

Glandular trichomes play a major role in the morphological characterization of the Bignoniaceae. Due to their great diversity of forms and functions, this study aimed to inventory the glandular trichomes present in the aerial vegetative axis of Amphilophium magnoliifolium, Martinella obovata and Stizophyllum riparium, analyze their structure and register the participation of ants in these plants. Fresh samples from the nodal region, petiole and from medium to apical regions of the leaflet blade were fixed and processed according to usual methods in light and scanning electron microscopies. The glandular trichomes found were: peltate, capitate, stipitate, and patelliform/cupular. Peltate trichomes are the most abundant ones and present the most uniform distribution. Patelliform/cupular trichomes occur at specific regions, such as prophylls, leaflet blade and nodal regions. Martinella obovata is the only species that presents capitate and stipitate trichomes, which are widely distributed along the entire aerial vegetative axis. Ants were found in all species, mainly at nodal regions. The occurrence of the capitate-type trichome is reported for the first time to the genus.(AU)

Tricomas glandulares desempenham papel importante na caracterização morfológica de Bignoniaceae e, devido à grande diversidade de formas e funções que esses tricomas apresentam, o objetivo desse estudo foi inventariar os tricomas glandulares presentes no eixo vegetativo aéreo de Amphilophium magnoliifolium, Martinella obovata. e Stizophyllum riparium, bem como analisar sua estrutura e registrar a participação de formigas nessas espécies. Amostras frescas da região mediana à apical das lâmina foliolar, pecíolo e nó foram fixadas e processadas de acordo com os métodos usuais para microscopia de luz e eletrônica de varredura. Os tricomas glandulares encontrados nas espécies foram: peltados, capitados, estipitados e pateliformes/cupuliformes. Dentre esses tipos o mais abundante foi o tricoma peltado, apresentando também uma distribuição mais uniforme que os demais. Os tricomas pateliformes/cupuliformes estavam em regiões mais específicas, como profilos, lâmina foliolar e na região nodal. Martinella obovata foi a única espécie que apresentou os tricomas capitados e estipitados, amplamente distribuídos ao longo de todo eixo vegetativo aéreo. Em todas as espécies foram encontradas formigas, principalmente nas regiões nodais. A ocorrência do tricoma capitado é relatada pela primeira vez para o gênero.(AU)

Structure and distribution of glandular trichomes in three species of Bignoniaceae / Estrutura e distribuição de tricomas glandulares em três espécies da família Bignoniaceae

Glandular trichomes play a major role in the morphological characterization of the Bignoniaceae. Due to their great diversity of forms and functions, this study aimed to inventory the glandular trichomes present in the aerial vegetative axis of Amphilophium magnoliifolium, Martinella obovata and Stizophyllum riparium, analyze their structure and register the participation of ants in these plants. Fresh samples from the nodal region, petiole and from medium to apical regions of the leaflet blade were fixed and processed according to usual methods in light and scanning electron microscopies. The glandular trichomes found were: peltate, capitate, stipitate, and patelliform/cupular. Peltate trichomes are the most abundant ones and present the most uniform distribution. Patelliform/cupular trichomes occur at specific regions, such as prophylls, leaflet blade and nodal regions. Martinella obovata is the only species that presents capitate and stipitate trichomes, which are widely distributed along the entire aerial vegetative axis. Ants were found in all species, mainly at nodal regions. The occurrence of the capitate-type trichome is reported for the first time to the genus.

Tricomas glandulares desempenham papel importante na caracterização morfológica de Bignoniaceae e, devido à grande diversidade de formas e funções que esses tricomas apresentam, o objetivo desse estudo foi inventariar os tricomas glandulares presentes no eixo vegetativo aéreo de Amphilophium magnoliifolium, Martinella obovata. e Stizophyllum riparium, bem como analisar sua estrutura e registrar a participação de formigas nessas espécies. Amostras frescas da região mediana à apical das lâmina foliolar, pecíolo e nó foram fixadas e processadas de acordo com os métodos usuais para microscopia de luz e eletrônica de varredura. Os tricomas glandulares encontrados nas espécies foram: peltados, capitados, estipitados e pateliformes/cupuliformes. Dentre esses tipos o mais abundante foi o tricoma peltado, apresentando também uma distribuição mais uniforme que os demais. Os tricomas pateliformes/cupuliformes estavam em regiões mais específicas, como profilos, lâmina foliolar e na região nodal. Martinella obovata foi a única espécie que apresentou os tricomas capitados e estipitados, amplamente distribuídos ao longo de todo eixo vegetativo aéreo. Em todas as espécies foram encontradas formigas, principalmente nas regiões nodais. A ocorrência do tricoma capitado é relatada pela primeira vez para o gênero.

Synopsis of Martinella Baill. (Bignonieae, Bignoniaceae), with the description of a new species from the Atlantic Forest of Brazil.

Martinella has traditionally included two species, Martinella iquitoensis and Martinella obovata, that are characterized by the presence of interpetiolar ridges surrounding the stems and minute prophylls of the axillary buds. A third species, Martinella insignis, is here described as new, illustrated and compared to other species in the genus. Martinella insignis is the first record of the genus in the Atlantic Forest of Brazil, and differs from other species of Martinella by the yellow corolla (vs. red to dark purple) and 5-lobed calices (vs. 2-4-lobed).

Phenotypic integration in flowers of neotropical lianas: diversification of form with stasis of underlying patterns.

Phenotypic integration is essential to the understanding of organismal evolution as a whole. In this study, a phylogenetic framework is used to assess phenotypic integration among the floral parts of a group of Neotropical lianas. Flowers consist of plant reproductive organs (carpels and stamens), usually surrounded by attractive whorls (petals and sepals). Thus, flower parts might be involved in different functions and developmental constraints, leading to conflicting selective forces. We found that Bignonieae flowers have very similar patterns of variance/covariance among traits and that such patterns are uncorrelated with the phylogenetic relationships between species. However, in spite of pattern stasis, our results also indicate that diversification of floral morphology in this group has occurred throughout the evolution of magnitudes of correlation among traits. Thus, we suggest that stabilizing selection has played an important role in phenotypic integration, resulting in the long-term stasis of covariance patterns underlying flower diversification during the ca. 50 Myr of evolution of Bignonieae. This is the first report of long-term stasis in the phenotypic integration of angiosperms, suggesting that patterns of floral morphology can be recognizable as specific attributes of distinct botanical families.

Primers for phylogeny reconstruction in Bignonieae (Bignoniaceae) using herbarium samples.

PREMISE OF THE STUDY: New primers were developed for Bignonieae to enable phylogenetic studies within this clade using herbarium samples. • METHODS AND RESULTS: Internal primers were designed based on available sequences of the plastid ndhF gene and the rpl32-trnL intergenic spacer region, and the nuclear gene PepC. The resulting primers were used to amplify DNA extracted from herbarium materials. High-quality data were obtained from herbarium samples up to 53 yr old. • CONCLUSIONS: The standardized methodology allows the inclusion of herbarium materials as alternative sources of DNA for phylogenetic studies in Bignonieae.