Wood resistance of Magonia pubescens (Sapindaceae), Dalbergia nigra, and Machaerium amplum (Fabaceae) to Nasutitermes sp. (Blattodea: Termitidae).

Termites of the genus Nasutitermes sp. (Blattodea: Termitidae), which feed on cellulose, may cause wood to become brittle and fragile. This study aimed to evaluate the natural resistance of three native wood species: Magonia pubescens (Sapindaceae), Dalbergia nigra and Machaerium amplum (Fabaceae) to attack by Nasutitermes sp. termites and to investigate the relationship between resistance, extractive content, and oven-dry density. Samples of each wood species were subjected to a forced feeding process with Nasutitermes sp. termites for 30 days. Following the exposure, the oven-dry density, extractive content, percentage of wood loss, and termite mortality were determined for each sample. Dalbergia nigra exhibited resistance to termite attack and had the highest extractive content at 13.14%. Conversely, M. amplum had the highest wood loss at 5.37% and the lowest extractive content at 1.94%. Both species showed a negative correlation between wood loss and extractive content, but no correlation with wood density. Magonia pubescens had the highest density at 0.90 g/cm3. Macherium amplum and M. pubescens caused 100% termite mortality, while D. nigra caused 40% mortality.

Structural Elucidation of an Atropisomeric Entcassiflavan-(4ß→8)-Epicatechin Isolated from Dalbergia monetaria L.f. Based on NMR and ECD Calculations in Comparison to Experimental Data.

A rare dihydoxyflavan-epicatechin proanthocyanidin, entcassiflavan-(4ß→8)-epicatechin, was isolated from Dalbergia monetaria, a plant widely used by traditional people from the Amazon to treat urinary tract infections. The constitution and relative configuration of the compound were elucidated by HR-MS and detailed 1D- and 2D-NMR measurements. By comparing the experimental electronic circular dichroism (ECD) spectrum with the calculated ECD spectra of all 16 possible isomers, the absolute configuration, the interflavan linkage, and the atropisomers could be determined.

Toxicological and chemoprevention studies of Dalbergia ecastaphyllum (L.) Taub. stem, the botanical source of Brazilian red propolis.

OBJECTIVES: Dalbergia ecastaphyllum (L.) Taub. is a semi-prostrate species associated with estuaries, mangroves and dunes. This plant species has great ecological and economic importance, especially concerning apiculture pasture and Brazilian red propolis production. In this study, non-clinical toxicological evaluations of the hydroalcoholic extract of D. ecastaphyllum stems (DEHE), the resin production source, were conducted. In addition, the action of DEHE on genomic instability and colon carcinogenesis was investigated. METHODS AND RESULTS: The extract's chemical profile was analysed by HPLC, and medicarpin, vestitol and neovestitol were found as major compounds. DEHE showed an IC50 equivalent to 373.2 µg/ml and LC50 equal 24.4 mg/L, when evaluated using the XTT colorimetric test and the zebrafish acute toxicity assay, respectively. DEHE was neither genotoxic nor cytotoxic at the highest dose, 2000 mg/kg, by peripheral blood micronucleus test. The treatments DEHE (6 and 24 mg/kg) led to the reduction of micronuclei induced by doxorubicin (DXR) in mice. Furthermore, significantly higher serum levels of reduced glutathione were observed in animals treated with DEHE plus DXR, revealing an antioxidant effect. Treatments with DEHE (48 mg/kg) led to a significant reduction in pre-neoplastic lesions induced by the 1,2-dimethylhydrazine (DMH) carcinogen in the rat colon. Immunohistochemical analysis revealed significantly lower levels of expression of COX-2 (86%) and PCNA (83%) in the colon of rats treated with DEHE plus DMH, concerning those treated with the carcinogen. CONCLUSIONS: These results indicate the involvement of anti-inflammatory and antiproliferative pathways in the protective effect of DEHE.

A new species of jewel beetle (Coleoptera, Buprestidae, Agrilus) triggers the production of the Brazilian red propolis.

Red propolis is a substance produced by bees by mixing resins from plants with wax, oils, and other secretions to protect the hive against natural enemies. Dalbergia ecastaphyllum (L.) Taub. (Fabaceae) is the primary botanical source of the Brazilian red propolis, where bees Apis mellifera L. collect a reddish resin from the stems to produce propolis. This species occurs in coastal dune and mangrove ecosystems, where local beekeepers install their beehives for propolis production. The induction of propolis production was virtually unknown. Previous reports and field evidence suggested that the reddish resin available in D. ecastaphyllum stems was not produced spontaneously but induced by the presence of a parasitic insect that feeds on the plant's stems. Research in the apiaries of the beekeepers' association of Canavieiras, Bahia, Brazil, led to the capture of a jewel beetle of an unknown species of the genus Agrilus Curtis (Buprestidae). It was confirmed that this jewel beetle is a red propolis production inductor. The adult and immature of this new species, Agrilus propolis Migliore, Curletti, and Casari sp. nov. are here described and illustrated. Behavioral information on the biology and chemical ecology confirms that the reddish resin of D. ecastaphyllum is directly related to the beetle attack and only occurs when Agrilus propolis sp. nov. adults emerge from the plant stem. This information is very important for Brazilian propolis producers interested in expanding red propolis production, which can have favorable effects on the economy of mangrove communities, promoting income generation, creating new business opportunities, and helping to sustain local communities and families.

Nonclinical Toxicological Studies of Brazilian Red Propolis and Its Primary Botanical Source Dalbergia ecastaphyllum.

Propolis is one of the most widely used products in traditional medicine. One of the most prominent types of Brazilian propolis is the red one, whose primary botanical source is Dalbergia ecastaphyllum (L.) Taub. Despite the potential of Brazilian red propolis for developing new products with pharmacological activity, few studies guarantee safety in its use. The objective of this study was the evaluation of the possible toxic effects of Brazilian red propolis and D. ecastaphyllum, as well as the cytotoxicity assessment of the main compounds of red propolis on tumoral cell lines. Hydroalcoholic extracts of the Brazilian red propolis (BRPE) and D. ecastaphyllum stems (DSE) and leaves (DLE) were prepared and chromatographed for isolation of the major compounds. RP-HPLC-DAD was used to quantify the major compounds in the obtained extracts. The XTT assay was used to evaluate the cytotoxic activity of the extracts in the human fibroblast cell line (GM07492A). The results revealed IC50 values of 102.7, 143.4, and 253.1 µg/mL for BRPE, DSE, and DLE, respectively. The extracts were also evaluated for their genotoxic potential in the micronucleus assay in Chinese hamster lung fibroblasts cells (V79), showing the absence of genotoxicity. The BRPE was investigated for its potential in vivo toxicity in the zebrafish model. Concentrations of 0.8-6.3 mg/L were safe for the animals, with a LC50 of 9.37 mg/L. Of the 11 compounds isolated from BRPE, medicarpin showed a selective cytotoxic effect against the HeLa cell line. These are the initial steps to determine the toxicological potential of Brazilian red propolis.

A validated HPLC-UV method for the analysis of phenolic compounds in Brazilian red propolis and Dalbergia ecastaphyllum.

Propolis is a natural product produced from the interaction between bees and plants. Brazilian red propolis results from Apis mellifera collection of resins from two plant species, being Dalbergia ecastaphyllum(L.) Taub, Fabaceae, the primary botanical source, containing isoflavonoids and other characteristic phenolic compounds. Several biological activities of Brazilian red propolis and their isolated compounds have been described in the literature. However, to our knowledge, there are no validated analytical methods for the analysis and standardization of products derived from this type of propolis reported in the literature. We developed a reverse-phase high-performance liquid chromatography analytical method for the detection and quantification of nine red propolis chemical markers: liquiritigenin, calycosin, isoliquiritigenin,formononetin, vestitol, neovestitol, medicarpin, biochanin A, and 7-O-methylvestitol, present in Brazilian red propolis extracts and D. ecastaphyllum. The developed method was also applied to the analyses of D. ecastaphyllum samples and seasonal analysis of Brazilian red propolis. Good detection response, linearity, precision, and robustness were obtained by the method, being reliable for the quality control of Brazilian red propolis extracts, raw propolis, plant material, and their derived products. The red propolis chemical markers were present in D. ecastaphyllum stems at lower concentrations. The seasonal analysis of Brazilian red propolis extract showed higher phenolic compound concentration on periods of the rainy season with higher humidity and lower solar radiation.

Characterization of Antibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant, by UHPLC-HRMS/MS.

Dalbergia monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. This paper describes a bio-guided study of ethanolic extracts from the bark and leaves of D. monetaria, in a search for metabolites active against human pathogenic bacteria. In vitro assays were performed against 10 bacterial strains, highlighting methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Fractioning of the extracts was performed using instrumental and classical techniques, and samples were characterized by UHPLC-HRMS/MS. Ethyl acetate fractions from bark and leaves showed similar antibacterial activities. EAFB is enriched in isoflavone C-glucosides and EAFL enriched in proanthocyanidins. Subfractions from EAFL presented higher activity and showed a complex profile of proanthocyanidins constructed by (epi)-cassiaflavan and (epi)-catechin units, including dimers, trimers and tetramers. The fragmentation pattern emphasized the neutral loss of cassiaflavan units by quinone-methide fission. Fraction SL7-6, constituted by (ent)-cassiaflavan-(ent)-cassiaflavan-(epi)-catechin isomers, showed the lowest MIC against the S. aureus and P. aeruginosa with values corresponding to 64 and 32 µg/mL, respectively. Cassiaflavan-proanthocyanidins have not been found previously in another botanical genus, except in Cassia, and the traditional medicinal use of D. monetaria might be related to the antibacterial activity of proanthocyanidins characterized in the species.

Dalbergia ecastaphyllum (L.) Taub. and Symphonia globulifera L.f.: The Botanical Sources of Isoflavonoids and Benzophenones in Brazilian Red Propolis.

The Brazilian red propolis (BRP) constitutes an important commercial asset for northeast Brazilian beekeepers. The role of Dalbergia ecastaphyllum (L.) Taub. (Fabaceae) as the main botanical source of this propolis has been previously confirmed. However, in addition to isoflavonoids and other phenolics, which are present in the resin of D. ecastaphyllum, samples of BRP are reported to contain substantial amounts of polyprenylated benzophenones, whose botanical source was unknown. Therefore, field surveys, phytochemical and chromatographic analyses were undertaken to confirm the botanical sources of the red propolis produced in apiaries located in Canavieiras, Bahia, Brazil. The results confirmed D. ecastaphyllum as the botanical source of liquiritigenin (1), isoliquiritigenin (2), formononetin (3), vestitol (4), neovestitol (5), medicarpin (6), and 7-O-neovestitol (7), while Symphonia globulifera L.f. (Clusiaceae) is herein reported for the first time as the botanical source of polyprenylated benzophenones, mainly guttiferone E (8) and oblongifolin B (9), as well as the triterpenoids ß-amyrin (10) and glutinol (11). The chemotaxonomic and economic significance of the occurrence of polyprenylated benzophenones in red propolis is discussed.

Leaf geometric morphometrics among populations of Dalbergia ecastaphyllum (L. ) Taub / Morfometria geométrica foliar entre populações de Dalbergia ecastaphyllum (L.) Taub. do Brasil

Leaves are plant structures that express important traits of the environment where they live. Leaf description has allowed identification of plant species as well as investigation of abiotic factors effects on their development, such as gases, light, temperature, and herbivory. This study described populations of Dalbergia ecastaphyllum through leaf geometric morphometrics in Brazil. We evaluated 200 leaves from four populations. The principal component analysis (PCA) showed that the first four principal components were responsible for 97.81% of variation. The non-parametric multivariate analysis of variance (NPMANOVA) indicated significant difference between samples (p = 0.0001). The Mentel test showed no correlation between geographical distances and shape. The canonical variate analysis (CVA) indicated that the first two variables were responsible for 96.77 % of total variation, while the cross-validation test showed an average of 83.33%. D. ecastaphyllum leaves are elliptical and ovate.

As folhas são estruturas presentes nas plantas que expressam importantes características de acordo com o ambiente no qual estão inseridas. Ao longo dos anos, a sua caracterização tem permitido identificar espécies vegetais e correlacionar o efeito de fatores abióticos como gases, luz, temperatura e herbivoria sob o seu desenvolvimento. O presente estudo teve como descrever populações de Dalbergia ecastaphyllum do Brasil utilizando a morfometria geométrica foliar. Foram avaliadas 200 folhas de quatro populações desta espécie. Análise de componentes principais (ACP) mostrou que os quatro primeiros componentes principais explicaram 97,81% da variação. A Análise de variância multivariada com teste não-paramétrico (NPMANOVA) indicou não haver diferença entres as amostras (p= 0,0001). Os resultados do teste de Mentel mostraram que não houve correlação das distâncias geográficas com a forma. Na análise de variação canônica, as duas primeiras variáveis responderam por 96,77 % da variação total, enquanto uma média de 83,33% foi encontrada pelo teste de validação cruzada. As folhas de D. ecastaphullym são elípticas e ovadas.

Comparative Analysis of the Antibacterial Activity and HPLC Phytochemical Screening of the Brazilian Red Propolis and the Resin of Dalbergia ecastaphyllum.

The aim of this study was to investigate the antibacterial activity of red propolis and resin and their association with standard antibiotics to evaluate possible differences of activity. We also submitted red propolis and the resin to a HPLC analysis to confirm the botanical origin. The extracts were tested against P. aeruginosa and S. aureus alone and in association with gentamicin and imipenem. The HPLC analysis identified seven compounds with six of them present in both substances. The lowest MIC values obtained in this study were observed against S. aureus. In general, MIC values showed to be lower for red propolis against all species tested in comparison to resin. Despite the synergistic behavior to be similar for both substances, we observed that inhibitory concentrations of drugs were lower when associated with red propolis in comparison to resin.

Dalbergia ecastaphyllum leaf extracts: in vitro inhibitory potential against enzymes related to metabolic syndrome, inflammation and neurodegenerative diseases

For the first time, the anti-hemolytic activity and the enzyme inhibitory activities of Dalbergia ecastaphyllum leaves extracts were tested against α-amylase, α-glucosidase, lipase, acetylcholinesterase, butyrylcholinesterase, tyrosinase and hyaluronidase. The phenolic profile of the obtained extracts was also investigated by high-performance liquid chromatography with photodiode array detection (HPLC-PAD). The extracts showed inhibitory activity against all enzymes evaluated, with the highest inhibitory activity reported for the enzyme hyaluronidase (28.28 ± 2.43 to 72.19 ± 1.40 μg mL-1). The obtained extracts also demonstrate anti-hemolytic activity (52.22 ± 1.62 to 71.17 ± 1.82%). Among the phenolic compounds identified, protocatechuic, vanillic and β-resorcylic acids were the most abundant (1.13 ± 0.06 to 2.53 ± 0.06, 0.90 ± 0.06 to 2.19 ± 0.06 and 1.03 ± 1.62 to 22.11 ± 1.62 mg L-1, respectively). In the statistical analysis, a significant correlation was found between the flavonoids content and all enzymes inhibitory activities. The present study showed that D. ecastaphyllum leaves extracts may have the potential to be used in the therapeutic treatment of several diseases such as Alzheimer, Parkinson, type 2 diabetes mellitus, hyperglycemia, and pigmentation, as well as those associated with oxidative stress.

Antioxidant, photoprotective and inhibitory activity of tyrosinase in extracts of Dalbergia ecastaphyllum.

Dalbergia ecastaphyllum is a native Brazil plant with importance for beekeeping, and widely used in folk medicine. For the first time, the extracts of this plant were assessed for the presence of hydrophilic and lipophilic antioxidants, as well as inhibition of tyrosinase, free radicals scavenging and sunscreen protection. The antioxidant activity was evaluated by free radical scavenging (DPPH) and ß-carotene bleaching assay. The tyrosinase inhibitory activity was evaluated and calculated the EC50. The photoprotective activity was measured using different concentrations of D. ecastaphyllum extracts. The Sun Protection Factor (SPF) of the samples was higher than 6, and the sample from Ilhéus showed the most pronounced photoprotective effect. Sample from Canavieiras presented the highest antioxidant activity by free radical scavenging DPPH and ß-carotene bleaching method, with 92.41% and 48.34%, respectively. All samples inhibited the tyrosinase, especially the sample from Prado that was most effective (124.62 µg.mL-1). Significant negative correlation was found between flavonoid contents and inhibition of tyrosinase. The overall results provide relevant information about the Dalbergia ecastaphyllum species, indicating as potential material to cosmetic and pharmaceutical industry.

Antitrypanosomal, antileishmanial and cytotoxic activities of Brazilian red propolis and plant resin of Dalbergia ecastaphyllum (L) Taub.

The treatment for leishmaniasis and Chagas disease can be hard and painful, such that many patients give up on the treatment. In order to find an alternative path for the treatment of these diseases, researchers are using natural products to fight these parasites. The aim of this study was to evaluate the antiprotozoan and cytotoxic activities of red propolis samples collected from different Brazilian states and seasons whilst searching for possible activity differences. We also compared the red propolis results with the ones obtained for the plant resin extract collected from Dalbergia ecastaphyllum trees. The hydroethanolic red propolis extracts from Pernambuco and Alagoas, and the D. ecastaphyllum resin were evaluated regarding their antileishmanial, antitrypanosomal and cytotoxic activity. All extracts showed antiprotozoan and cytotoxic activity. RP-PER showed to be more cytotoxic against protozoan parasites and fibroblast cells. All propolis extracts showed a higher cytotoxic activity when compared to resin extracts. The propolis sample collected in Pernambuco during the rainy season killed the parasites with lower concentrations than the sample collected in the dry season. The IC50 observed against the parasites could be used without high fibroblast cell damage.

Anti-staphylococcal properties of four plant extracts against sensitive and multi-resistant bacterial strains isolated from cattle and rabbits.

The aim of this study is to investigate the biopotency of methanolic extracts of Vitex mollis, Psidium guajava, Dalbergia retusa, and Crescential alata leaves against various staphylococcal strains isolated from cattle and rabbits. Methicillin-resistant S. aureus strains were isolated from cattle, while other strains were isolated from rabbits using standard methodology. The total phytochemical phenolic and saponins contents were obtained being the main groups of the antinutritional factors. The antimicrobial activity of the extracts against the standard culture of S. aureus (control) and S. aureus isolated from cattle and rabbits were investigated comparatively relative to that of oxacillin. It was found that both the control S. aureus and the isolated S. aureus are susceptible to all the four plant extracts, and sensitive to oxacillin. Of all the S. aureus including the control, MRSA2 is the most susceptible to all the extracts at 1000 µg/mL, except that of V. mollis where it is the least susceptible. Among all the plant extracts, P. guajava is the most active against MRSA2 and SOSA2. Therefore, the isolates from cattle (MRSA1 and MRSA2) are more susceptible to all the plant extracts than the isolates from rabbits. Among all the rabbit isolates, CoNS3 is the least susceptible to the extracts. Since all the plant extracts exhibit remarkable inhibitory activities against all the S. aureus strains, they are promising towards the production of therapeutic drugs.

Biological Activities of Red Propolis: A Review.

BACKGROUND: The red propolis (RdProp) is a resin produced by Apis mellifera bees, which collect the reddish exudate on the surface of its botanic source, the species Dalbergia ecastophyllum, popularly known in Brazil as "rabo de bugio". Considered as the 13th type of Brazilian propolis, this resin has been gaining prominence due to its natural composition, rich in bioactive substances not found in other types of propolis. OBJECTIVE: This review aims to address the most important characteristics of RdProp, its botanical origin, the main constituents, its biological properties and the patents related to this natural product. METHOD: By means of the SciFinder, Google Patents, Patus® and Spacenet, scientific articles and patents involving the term "red propolis" were searched until August 2017. RESULTS: A number of biological properties, including antimicrobial, anti-inflammatory, antiparasitic, antitumor, antioxidant, metabolic and nutraceutical activities are attributed to RdProp, demonstrating the great potential of its use in the food, pharmaceutical and cosmetics industries. CONCLUSION: The available papers are associated to pharmacological potential of RdProp, but the molecular mechanisms or bioactive compounds responsible for each activity have not yet been fully elucidat ed. The RdProp patents currently found are directed to components for the pharmaceutical industry (EP2070543A1; WO2014186851A1; FR3006589A1; CN1775277A; CN105797149A; CN1879859A), cosmetic (JP6012138B2; JP2008247830A; JP6012138B2) and food (JP5478392B2; CN101380052A; WO2006038690A1).

Diferentes meios de cultura e antioxidantes no estabelecimento in vitro do Jacarandá da Bahia / Different culture media and antioxidants in vitro establishment of Jacaranda da Bahia

O Jacarandá da Bahia é uma espécie florestal nativa pertencente a família Leguminosaea Papilionoideae com ocorrência desde o sul da Bahia até o estado de São Paulo. O extrativismo e a pecuária contribuíram para a sua quase extinção e apesar disso, pouco tem sido feito para a multiplicação desta espécie. A micropropagação é uma alternativa para obtenção de grande quantidade de mudas sadias em curto espaço de tempo. Foram utilizados meristemas apicais e gemas axilares de plântulas de Jacarandá da Bahia, cultivadas em condições assépticas nos tratamentos compostos por meios de cultura (MS e WPM), concentrações de BAP (4, 9 e 18 µM) e com a ausência ou presença de agente antioxidante (PVP ou carvão ativado), totalizando 18 tratamentos, cada um com 10 repetições. As avaliações foram realizadas com 4 e 8 semanas de cultivo, considerando a porcentagem de explantes oxidados. Os meios de cultura de antioxidantes testados não diferiram estatisticamente entre si, porém tratamentos com BAP na concentração de 18 µM foram os que apresentaram maior oxidação.

Dalbergia nigra is a native forest species belonging the Papilionoideae-Leguminosaea family occurring from southern Bahia to the state of Sao Paulo. The extraction and livestock contributed to its near extinction and yet little has been done to the multiplication of this species. The micropropagation techniques are an alternative in order to achieve a large amount of seedlings in a short time and under conditions plant without diseases. Used apical and lateral meristems of Dalbergia nigra seedlings, grown in aseptic conditions in treatments consisting of different culture media (MS and WPM), BAP concentrations (4, 9 and 18 µM) and the absence or presence of antioxidant agent (PVP or activated charcoal), all crossed each other, totaling 18 treatments, each with 10 repetitions. Evaluations were performed at 4 and 8 weeks of cultivation, considering the percentage of browning explants. The culture media of antioxidants tested did not differ statistically, but BAP at a concentration of 18 µM were those with the highest oxidation.

Heat shock effects on seed germination of five Brazilian savanna species.

Fire is considered an important factor in influencing the physiognomy, dynamics and composition of Neotropical savannas. Species of diverse physiognomies exhibit different responses to fire, such as population persistence and seed mortality, according to the fire frequency to which they are submitted. The aim of this study is to investigate the effects of heat shocks on seed germination of Anadenanthera macrocarpa (Benth.) Brenan, Dalbergia miscolobium Benth., Aristolochia galeata Mart. & Zucc., Kielmeyera coriacea (Spreng.) Mart. and Guazuma ulmifolia Lam., which are native species of the Brazilian savanna. The temperatures and exposure times to which the seeds were submitted were established according to data obtained in the field during a prescribed fire: 60 °C (10, 20 and 40 min), 80 °C (5, 10 and 20 min) and 100 °C (2, 5 and 10 min). Untreated seeds were used as controls. Seeds of A. galeata and K. coriacea showed high tolerance to most heat treatments, and seeds of A. macrocarpa showed a significant reduction in germination percentage after treatments of 80 °C and 100 °C. Treatments of 100 °C for 10 min reduced germination percentage for all species except G. ulmifolia, which has dormant seeds. For this species, germination was accelerated by heat treatments. The high temperatures applied did not interfere with the time to 50% germination (T(50) ) of the tolerant seeds. Seeds of the savanna species K. coriacea and A. galeata were more tolerant to heat shocks than seeds of the forest species A. macrocarpa. Guazuma ulmifolia, the forest species with seeds that germinate after heat shock, also occurs in savanna physiognomies. Overall, the high temperatures applied did not affect the germination rate of the tolerant seeds.

Phenotypic plasticity to light of two congeneric trees from contrasting habitats: Brazilian Atlantic Forest versus cerrado (savanna).

The Brazilian Atlantic Forest is a typically multi-layer tropical forest, while cerrado (savanna) is a patchy habitat with different physiognomy. Despite these differences, both habitats have high light heterogeneity. Functional traits of Dalbergia nigra and D. miscolobium from the Atlantic Forest and cerrado, respectively, were evaluated under shade (25% of full sunlight) and full sunlight in a nursery experiment. We hypothesised that both species should benefit from high phenotypic plasticity in relation to light. Plasticity was estimated using the relative distance phenotypic index (RDPI). D. miscolobium had lower shoot growth under both light conditions, suggesting it has low competitive capacity in the forest environment, which could explain its limited ability to expand over areas of Atlantic Forest. The studied species exhibited photoprotection strategies under high light and improved light capture under low light. Stomatal conductance, ETR(max) (maximum electron transport rate), PPFD(sat) (saturating photosynthetically active photon flux density), chlorophyll and carotenoid content had higher RDPI than stem morphological traits. Although both species showed considerable phenotypic plasticity, D. miscolobium had higher RDPI for eight of 11 evaluated traits. This high plasticity could be one of the factors that explain the occurrence of this species in a wide range of environmental conditions, from open grassland to dense woodlands, and it could also reflect its adaptation to high light. D. nigra also had considerable plasticity and good growth performance in both shade and full sunlight, but its absence in areas of cerrado suggests that factors other than light limit its occurrence in these habitats.

Diversity and genetic connectivity among populations of a threatened tree (Dalbergia nigra) in a recently fragmented landscape of the Brazilian Atlantic Forest.

In this study we evaluated the influence of recent landscape fragmentation on the dynamics of remnant fragments from the Brazilian Atlantic Forest. This biome is one of the richest in the world and has been extensively deforested and fragmented. We sampled five populations of the threatened Dalbergia nigra, a tree endemic to the Brazilian Atlantic Forest, two located in a large reserve of continuous forest and three in fragments of different sizes and levels of disturbance. In order to assess historical changes, considering the longevity of the analyzed species, 119 adults and 116 saplings were genotyped for six microsatellite loci. Lower levels of genetic diversity were found in the most impacted fragments when compared to the most preserved population located inside the reserve, and there was significant genetic structure among the populations studied (pairwise F(ST) = 0.031-0.152; pairwise D(EST) = 0.039-0.301). However, genetic structure among saplings (F ST) = 0.056; D(EST) = 0.231) was significantly lower than among adults (F(ST) = 0.088; D(EST) = 0.275). Estimates of contemporary gene flow based on assignment tests corroborated this result, suggesting that fragmentation led to an increase in gene flow. This connectivity among remnant fragments could mitigate the loss of genetic diversity through a metapopulation dynamic, but the high rate of habitat loss and the unknown long-term genetic effects add uncertainty. These results, taken together with the presence of private alleles in disturbed populations, highlight the importance of preserving the extant fragments.

Comparison of RAPD and ISSR markers for assessment of genetic diversity among endangered rare Dalbergia oliveri (Fabaceae) genotypes in Vietnam.

Dalbergia oliveri is a leguminous tree of the Fabaceae family. This species is popular and valuable in Vietnam and is currently listed on the Vietnam Red List and on the IUCN Red List as endangered. Two PCR techniques using RAPD and inter-simple sequence repeat (ISSR) markers were used to make a comparative analysis of genetic diversity in this species. Fifty-six polymorphic primers (29 RAPD and 27 ISSR) were used. The RAPD primers produced 63 bands across 35 genotypes, of which 24 were polymorphic. The number of amplified bands varied from one to four, with a size range from 250 to 1400 bp. The percentage polymorphism ranged from 0 to 75. Amplification of genomic DNA of the 35 genotypes, using ISSR analysis, yielded 104 fragments, of which 63 were polymorphic. The number of amplified fragments using ISSR primers ranged from one to nine and varied in size from 250 to 1500 bp. The percentage polymorphism ranged from 0 to 100. ISSR markers were relatively more efficient than RAPDs. The mental test between two Jaccard's similarity matrices gave r ≥0.802, showing good fit correlation between ISSRs and RAPDs. Clustering of isolates remained more or less the same for RAPDs compared to combined RAPD and ISSR data. The similarity coefficient ranged from 0.785 to 1.000, 0.698 to 0.956 and 0.752 to 0.964 with RAPD, ISSR, and the combined RAPD-ISSR dendrogram, respectively.