Screening for inhibitory activity of volatile oils from Piper spp. on acetylcholinesterase and α-glucosidase

The Atlantic Forest is regarded a rich source of aromatic plants with a broad spectrum of biological properties. The leaves of seven Piper species were collected from the Atlantic Forest domain in the coastal region of Paraná state in winter (W) and spring (S). The volatile oils were extracted from the leaves through hydrodistillation method. The volatile oils were characterized by means of GC-FID and GC-MS. Sesquiterpenes were among the major compounds in all species studied, with many dozens of representatives. However, very low concentrations of monoterpenes were observed; α-pinene in Piper mosenii and P. cernuum, δ-3-carene in P. rivinoides, camphene and β-pinene in P. cernuum are exceptions. The arylpropanoides myristicine and elemicin were found in considerable amount in P. diospyrifolium (26.2%/S) and P. mosenii (16.4%/W), respectively. These oils were also screened for inhibitory activities against acetylcholinesterase (AChE) and α-glucosidase (AG). For AChE the most active samples were P. diospyrifolium, P. aduncum and P. cernuum, with inhibiting level > 93%. For the less sensitive AG, the most promising candidates were P. diospyrifolium and P. mosenii, with inhibiting level > 65%. These results highlight the importance of native plants as renewable source of new inhibitors for AChE and AG. Further investigation is required to identify the most active constituents or fractions from the selected volatile oils.

Impact of saline solution on growth and photosystem II during in vitro cultivation of Bromelia antiacantha (Bromeliaceae)

In vitro cultivation is a technique with wide application for micropropagation. However, each species has specific mineral needs for this type of cultivation. The objective was to assess the impacts of the saline solution culture medium on the performance of the photosynthetic apparatus and growth of Bromelia antiacantha during in vitro cultivation, and thus to elucidate the mitigation of the nutritional imbalance that can interfere in the electron transport in the plants. Plants were cultivated in a salt concentration gradient of MS medium (0%, 25%, 50%, 75% or 100%). The growth traits and fluorescence a chlorophyll were analyzed. Intermediate concentrations of MS medium resulted in plants with a larger number of leaves and longer root length. The OJIP curves and results of the JIP test showed that the plants grown without MS salts presented less efficient photosystem II (PSII), as indicated by the performance index [Pi(total)]. In contrast, the intermediate concentrations (MS 25% and 50%) had a positive effect on the performance of the photosynthetic apparatus. The MS 25% medium can be used for in vitro cultivation of B. antiacantha, enabling the development of plants with suitable physiological qualities for planting in the field.

Genetic diversity and structure of Dorstenia elata (Moraceae) in an Atlantic Forest remnant

Plant species that show gregarious spatial distribution and endemism to the Atlantic Forest, such as Dorstenia elata, are particularly sensitive to the effects of genetic diversity loss. In the present study, we aimed to quantify the genetic diversity in native populations of this species in an Atlantic Forest remnant. The sample included three aggregates of individuals, and molecular characterization was performed with twelve ISSR primers. Intrapopulation analyses were based on the calculation of the Shannon index; total expected heterozygosity and the matrix of distances between pairs of individuals were also calculated. The obtained grouping dendrogram evinced the formation of two groups. Interpopulation investigations were based on the analysis of molecular variance and the estimate of historical gene flow. The results demonstrate that one group comprised the genotypes from two subpopulations, and the other contained exclusively the genotypes of a third subpopulation. The greatest genetic variability was observed within rather than among populations, indicating that the geographical distance and the road that divides the studied populations are not causing loss of genetic diversity.

Micropropagation of Tarenaya rosea (Cleomaceae) from leaf explants

In vitro culture techniques are recognized as efficient strategies for large-scale plant production, as well as providing alternatives for plant conservation. In this study the micropropagation of Tarenaya rosea was established using petiole and foliar blade segments cultivated on MS medium with 6-benzyladenine (BA) and/or 6-furfurylaminopurine (KIN). The regeneration rate from explants was evaluated after 30-days in culture, as well as the proliferation rate from explant-derived shoots, reached after four subcultures performed at 30-days in culture. In vitro propagation occurred by both direct (DO) and indirect (IO) organogenesis. The highest regeneration rates by DO (50% to 100%) were reached on media containing only BA, while morphogenic calluses (IO) were mainly formed with BA+KIN. Explants on media with BA showed the presence of small black nodules on their surface, and histological analysis revealed the presence of trichomes with anthocyanin content. Elongation and rooting were reached on growth regulator-free MS. Acclimatization rates around 80% were achieved and the in vitro-regenerated plants were successfully maintained under field conditions. Results show significant morphogenetic potential of T. rosea from leaf explants, mainly when cultivated in the presence of 4.4 µM BA, providing a new alternative source of plant material for biotechnological and in vitro conservation studies.

Morphoanatomical and histochemical studies of the seed development of Euterpe oleracea (Arecaceae)

Although the consumption of açaí (Euterpe oleracea) pulp has long been an important component of the diet of the peoples from the Amazon, the açaí palm tree has recently attracted economic and scientific interest because of its vast array of bioactive compounds found in the fruit pericarp. The açaí seeds are the largest byproduct after pulp extraction and have potential for use in ethanol production, but this process is hindered by limited knowledge of seed biology, chemical composition and pattern reserve deposition during seed development. The aim of this work was to describe the morphoanatomical development of the seeds, as well as to identify the main organic compounds stored in the seeds. To achieve this goal, histological and histochemical analyses were performed on developing seeds. Results showed the seed is albuminous, bitegmic and that ingrowths of the seed coat give rise to a ruminate endosperm. Moreover, the nutritive reserves of açaí seeds are found in the endosperm thickened cell walls as reserve polysaccharides. Our findings provide information for future studies dealing with reproductive biology, propagation and the improvement of this profitable crop.

The relative effect of altitude and aspect on saxicolous lichen communities at mountain summits from central-west of Argentina

The altitudinal patterns of lichen communities in altitudinal gradients are very variable. The changes that occur along the mountains depend on climatic factors but also on microsite variables such as substrate type and aspect. The effect of altitude and aspect on richness, cover and composition of saxicolous lichens communities along an elevation gradient in extra Andean mountains from the central-west of Argentina was studied. Rock outcrops on the north and south aspect of three mountain summits distributed between 2,500 and 4,500 m.a.s.l. were sampled. Lichen species present in a 20 × 20 cm square were identified and the relative cover was measured using digital photography. Richness, cover and composition were analyzed through linear models and multivariate analysis. Fifty-eight saxicolous lichen species were identified between the three sites. Richness and cover were maximum at middle altitude. Also compositional differences among communities of each mountain summit were found. Finally, the effect of the aspect was significant at lower altitudes for cover and composition.

Climbing plants from Seridó Ecological Station: diversity, interactive key and five new records from Rio Grande do Norte state, Brazil

In Brazil, Seasonally Dry Tropical Forests (SDTFs) are represented by Caatinga, which exhibits one of the greatest species richness and endemisms among the Neotropical SDTFs. However, studies of the flora of this biome remain deficient, especially in scientifically neglected areas, such as the Seridó region. Located between the states of Rio Grande do Norte (RN) and Paraíba, the Seridó region has an underestimated floristic diversity, especially for non-arboreal components such as climbers. Given this scenario, the study aimed to survey the climbers of the Seridó Ecological Station, a federal conservation unit located in the RN state, as well as to provide a multiple access online identification key. Collections were carried out from 2018 to 2019, as well as consultation of material deposited at the UFRN herbarium. In total, 56 species were listed, being 33 herbaceous and 23 woody climbers, respectively, adding 14 species of climbers to the previous checklist of the unit. Five new occurrences were found for the state of Rio Grande do Norte: Cuscuta globosa, Cuscuta partita (Convolvulaceae), Macroptilium bracteatum (Fabaceae), Heteropterys trichanthera and Tetrapterys longibracteata (Malpighiaceae), being the latest a new occurrence of the genus Tetrapterys for the state. Convolvulaceae is the most representative family (18 spp.), followed by Fabaceae (10 spp.), Apocynaceae (eight spp.) and Cucurbitaceae (five spp.). This is the first study that provides an interactive identification key for the Seridó region and for the RN state. The interactive identification key is published throughout the Xper³ platform, and can be accessed at <xper3.fr/xper3GeneratedFiles/publish/identification/-4505993480748774750/mkey.html>.

Dinâmicas de conhecimento e uso de plantas medicinais em um assentamento rural de Belém do Pará - PA

Resumo Os agricultores familiares que vivem em áreas de assentamentos rurais estão entre os diversos grupos sociais da Amazônia que detêm um amplo conhecimento sobre o uso de plantas medicinais. Estudos realizados neste contexto revelam uma vasta heterogeneidade no conhecimento e uso de plantas medicinais, bem como a influência dessas comunidades na diversidade vegetal e nos aspectos culturais associados ao seu uso. Esta pesquisa traz informações sobre a dinâmica do conhecimento e uso de plantas medicinais no Assentamento Rural Paulo Fonteles, estabelecido desde o ano de 2006 no Distrito de Mosqueiro, Município de Belém, estado do Pará. Os dados foram obtidos através de entrevistas semiestruturadas e oficinas participativas e analisados qualitativa e quantitativamente. As plantas medicinais são recursos prioritários para os assentados em períodos que antecedem e sucedem a ocupação. Foram registradas 140 plantas medicinais, das quais, 119 foram identificadas e pertencem a 58 famílias botânicas. Sessenta espécies são nativas do Brasil, sendo 21 com domínio fitogeográfico restrito a Amazônia e 59 são introduzidas. O conhecimento local de plantas medicinais encontra-se bem difundido entre informantes de diferentes classes de idade e gênero. As pessoas provenientes de outras regiões do Brasil reportaram um acervo de plantas medicinais significativamente maior do que àquelas naturais do estado do Pará. Entre as 140 plantas mencionadas, 110 referem-se a espécies cujos usos foram mantidos ao longo do tempo pelos informantes. A heterogeneidade sociocultural e a dinâmica do modo de vida dos assentados rurais contribuem para o acúmulo de saberes e no incremento da diversidade da flora local.

Malpighiaceae from Lenheiro Mountain Range, Minas Gerais, Brazil

We present a taxonomic treatment for Malpighiaceae from the Lenheiro Mountain Range, São João del-Rei, Minas Gerais, Brazil, where a total of 23 species and nine genera were recorded. Identification keys for all genera and species are presented, along with morphological descriptions, photo plates, and comments on distribution, ecology and taxonomy of the studied species.

Quararibea bovinii (Malvaceae), a new species from the Brazilian Atlantic Forest

In the present study, I propose a new species, Quararibea bovinii, an Atlantic Forest tree. The new taxon occurs in southeastern Brazil, in the states of Espírito Santo, Rio de Janeiro, and São Paulo. It resembles Q. similis in terms of floral morphology and fruit shape, but it is distinguished by the indumenta of leaves, leaf width, and seed shape.