Economic Potential of Selected Native Plants from Cuanza Norte,Northern Angola

Economic Botany - This study examines the economic potential of 12 native Angolan plant species. In October/November 2016, field trips and market analyses were conducted in the province of Cuanza...     

From Forgotten Taxon to a Missing Link? The Position of the Genus Verhuellia (Piperaceae) Revealed by Molecules

BACKGROUND AND AIMS: The species-poor and little-studied genus Verhuellia has often been treated as a synonym of the genus Peperomia, downplaying its significance in the relationships and evolutionary aspects in Piperaceae and Piperales. The lack of knowledge concerning Verhuellia is largely due to its restricted distribution, poorly known collection localities, limited availability in herbaria and absence in botanical gardens and lack of material suitable for molecular phylogenetic studies until recently. Because Verhuellia has some of the most reduced flowers in Piperales, the reconstruction of floral evolution which shows strong trends towards reduction in all lineages needs to be revised. METHODS: Verhuellia is included in a molecular phylogenetic analysis of Piperales (trnT-trnL-trnF and trnK/matK), based on nearly 6000 aligned characters and more than 1400 potentially parsimony-informative sites which were partly generated for the present study. Character states for stamen and carpel number are mapped on the combined molecular tree to reconstruct the ancestral states. KEY RESULTS: The genus Peperomia is generally considered to have the most reduced flowers in Piperales but this study shows that this is only partially true. Verhuellia, with almost equally reduced flowers, is not part of or sister to Peperomia as expected, but is revealed as sister to all other Piperaceae in all analyses, putting character evolution in this family and in the perianthless Piperales in a different light. A robust phylogenetic analysis including all relevant taxa is presented as a framework for inferring patterns and processes of evolution in Piperales and Piperaceae. CONCLUSIONS: Verhuellia is a further example of how a molecular phylogenetic study can elucidate the relationships of an unplaced taxon. When more material becomes available, it will be possible to investigate character evolution in Piperales more thoroughly and to answer some evolutionary questions concerning Piperaceae.     

The extraordinary journey of Peperomia subgenus Tildenia (Piperaceae): insights into diversification and colonization patterns from its cradle in Peru to the Trans‐Mexican Volcanic Belt

Aim Peperomia subgenus Tildenia consists of c. 60 species growing in seasonal habitats of Neotropical mountain areas from Mexico to Argentina. The subgenus can be split geographically, with almost equal diversity in the Northern Hemisphere (centred in Mexico and Guatemala) and in the Southern Hemisphere (centred in Peru and Bolivia). Only a few species are known from a limited number of localities between these two hotspots. As such, Tildenia is an ideal candidate with which to test time, direction and mode of migration of high mountain taxa against the background of the ‘Great American Biotic Interchange’. Location The Andes with focus on the Central Andes, and the Mexican mountain chains, especially the Trans‐Mexican Volcanic Belt. Methods To elucidate the spatio‐temporal origin, subsequent colonization and radiation of Tildenia, we combine Bayesian phylogenetics based on the chloroplast trnK–matK–psbA region, georeferenced distribution data, and fossil calibrated molecular dating approaches using both penalized likelihood and relaxed phylogenetics. Reconstruction of the ancestral distribution area was performed using dispersal–vicariance analysis and dispersal–extinction–cladogenesis. Results Peperomia subgenus Tildenia is subdivided into six Andean clades and one Mexican and Central American clade originating from a north/central Peruvian ancestor. Molecular dating approaches converge on a stem age of c. 38 Ma for Tildenia and a mostly Miocene diversification and colonization. Main conclusions We detect a strong correlation between diversification of Tildenia and orogenetic events in the respective distribution centres. In the Andes, distribution was influenced by the Altiplano–Eastern Cordillera System as well as the Amotape‐Huancabamba Zone, where the latter serves as both migration barrier and migration bridge for different clades. In contrast to most studies of high‐elevation taxa, we provide support for a south–north colonization towards Central America and Mexico, and provide additional, independent evidence for the latest view on the timing of the Great American Biotic Interchange. In Mexico, the Trans‐Mexican Volcanic Belt has played a major role in more recent radiations together with climatic oscillation and the formation of refugia.     

Genetic diversity in the locally declining <Emphasis Type="Italic">Laserpitium prutenicum</Emphasis> L. and the more common <Emphasis Type="Italic">Selinum carvifolia</Emphasis> (L.) L.: a “silent goodbye”?

Evaluating the consequences of the decline of threatened species on their population genetic structure is crucial for establishing effective conservation strategies in the strongly fragmented landscapes of Central Europe. Laserpitium prutenicum is a bi- to perennial forb occurring in intermittently wet meadows and light oak forests throughout central to eastern and south-eastern Europe. During the past 70 years, the western limit of its distributional range retracted dramatically, the number of populations decreased and the remaining populations faced a considerable increase of fragmentation. To study the effects of this decline on the genetic diversity of L. prutenicum, we conducted an AFLP study on 20 populations from Germany, Poland and the Czech Republic. For comparison, we collected the same data on Selinum carvifolia, a taxonomically related and both ecologically and morphologically similar species, which is still more common in the study area. Both species showed similarly weak spatial genetic structuring and intermediate genetic diversities. We attribute this result to the loss of habitat being faster than the loss of genetic diversity in smaller and fragmented populations. Depending on the ecological characteristics of a species, even a gradual disappearance is not necessarily accompanied by any detectable effect at the population genetic level (“silent goodbye”). In the case of L. prutenicum, habitat preservation should be given priority over all other conservation measures.     

Wettability and Contaminability of Insect Wings as a Function of Their Surface Sculptures

Abstract The wing surfaces of 97 insect species from virtually all relevant major groups were examined by high resolution scanning-electron-microscopy, in order to identify the relationships between the wing microstructures, their wettability with water and their behaviour under the influence of contamination. Isolated wings with contact angles between 31.6° and 155.5° were artificially contaminated with silicate dusts and subsequently fogged until drops of water (“dew”) formed and rolled off. The remaining particles were counted via a digital image analysis system. Remaining particle values between 0.41% and 103% were determined in comparison with unfogged controls. Some insects with very unwettable wings show a highly significant “self-cleaning” effect under the influence of rain or dew. Detailed analysis revealed that there is a correlation between the wettability and the “SM Index” (quotient of wing surface/(body mass)^0.67) with values ranging from 2.42 to 57.0. Furthermore, there is a correlation between the “self-cleaning” effect and the SM Index, meaning that taxa with a high SM Index, e.g. “large-winged” Ephemeroptera, Odonata, Planipennia, and many Lepidoptera, have very unwettable wings and show high particle removal due to dripping water drops. The “small-winged” insects, such as Diptera and Hymenoptera, and insects with elytra, such as Blattariae, Saltatoria, Heteroptera and Coleoptera, show completely opposite effects. This is clearly a result of the fact that species with a high SM Index are, in principle, more restricted in flight by contamination than species with a low SM Index which can also actively clean their own wings. The wings primarily serve a protection function in insects with elytra, so that the effects of contamination are probably of minor importance in these insects. Copyright © 1996 The Royal Swedish Academy of Sciences. Published by Elsevier Science Ltd.     

Plant pressure sensitive adhesives: similar chemical properties in distantly related plant lineages

Main conclusion

A mixture of resins based on aliphatic esters and carboxylic acids occurs in distantly related genera Peperomia and Roridula , serving different functions as adhesion in seed dispersal and prey capture. According to mechanical characteristics, adhesive secretions on both leaves of the carnivorous flypaper Roridula gorgonias and epizoochorous fruits of Peperomia polystachya were expected to be similar. The chemical analysis of these adhesives turned out to be challenging because of the limited available mass for analysis. Size exclusion chromatography and Fourier transform infrared spectroscopy were suitable methods for the identification of a mixture of compounds, most appropriately containing natural resins based on aliphatic esters and carboxylic acids. The IR spectra of the Peperomia and Roridula adhesive resemble each other; they correspond to that of a synthetic ethylene–vinyl acetate copolymer, but slightly differ from that of natural tree resins. Thus, the pressure sensitive adhesive properties of the plant adhesives are chemically proved. Such adhesives seem to appear independently in distantly related plant lineages, habitats, life forms, as well as plant organs, and serve different functions such as prey capture in Roridula and fruit dispersal in Peperomia. However, more detailed chemical analyses still remain challenging because of the small available volume of plant adhesive.

     

Plants from disturbed savannah vegetation and their usage by Bakongo tribes in Uíge,Northern Angola

Background

This study represents the first in-depth ethnobotanical study in the province of Uíge in northern Angola and documents the traditional knowledge of the Bakongo people living in the area. Due to deforestation and frequent fires, degraded savannahs dominate the landscape in the study region. Here we provide a list of useful plants from these savannahs including quantitative data about cultural importance of the respective species, aiming on the one hand to conserve the local knowledge and on the other hand to create a reliable basis for research projects in the region.

Methods

Field work was conducted in April and May 2014 in 5 municipalities of Uíge province. The study is based on 32 semi-structured and free-listing interviews, group discussions of varying scope and 14 field trips, involving a total of 82 informants. Throughout the course of the study herbarium specimens of the useful species were collected for later identification. Cultural importance index was applied to analyse the data sets recorded and to determine the best-known useful species in the region. All data sets were compared to the literature available for the region.

Results

The study documents a total of 498 citations for the use of 122 plants from 48 families, 34.0 % of which were unknown according to the literature used for comparison. The high amount (71 %) of medical use-reports indicates that plants still play a crucial role in rural health care. We identified 14 plant species of special interest for pharmacological analysis. Species of highest cultural importance are Annona senegalensis Pers. and Sarcocephalus latifolius (Sm.) E.A., both of which are frequently found in disturbed savannahs.

Conclusions

The study points out the importance of savannahs even if degraded in terms of useful plants and provides a valuable addition to current knowledge of plant use in Northern Angola. This is not only essential for further studies, i.e. regarding pharmaceutical agents, but also for the design of a planned botanical garden of the University Kimpa Vita in Uíge, which aims at communicating the findings to the local people.

     

Smart skin patterns protect springtails

Springtails, arthropods who live in soil, in decaying material, and on plants, have adapted to demanding conditions by evolving extremely effective and robust anti-adhesive skin patterns. However, details of these unique properties and their structural basis are still unknown. Here we demonstrate that collembolan skin can resist wetting by many organic liquids and at elevated pressures. We show that the combination of bristles and a comb-like hexagonal or rhombic mesh of interconnected nanoscopic granules distinguish the skin of springtails from anti-adhesive plant surfaces. Furthermore, the negative overhang in the profile of the ridges and granules were revealed to be a highly effective, but as yet neglected, design principle of collembolan skin. We suggest an explanation for the non-wetting characteristics of surfaces consisting of such profiles irrespective of the chemical composition. Many valuable opportunities arise from the translation of the described comb-like patterns and overhanging profiles of collembolan skin into man-made surfaces that combine stability against wear and friction with superior non-wetting and anti-adhesive characteristics.     

Diversity and potential correlations to the function of Collembola cuticle structures

Collembola (springtails) are soil arthropods, representing the most widespread hexapod group worldwide. Being skin-breathing animals, Collembola evolved special cuticular patterns, which are robust and antiadhesive allowing cuticular respiration under humid conditions in the soil environment. Details about function and formation of these unique cuticle characters are still unknown. Here we demonstrate that a high diversity of cuticular structures exists and that the different observed structural patterns of Collembola cuticles might go along with specific adaptations to life in soil. We examined the cuticle structures of 40 different species using scanning electron microscopy and compared the cuticle patterns of the different species with information about their preferred habitat. In addition, we compare the results with current systematic concepts, showing that certain cuticle structures are typical for different collembolan groups.