Resumo em Inglês:

ABSTRACT Cell coverings can be observed in all major groups of organisms, which include animals, plants, fungi, protists and prokaryotes. They play a key role in assuring cell survival or adaptation to certain environmental conditions. Since the term algae refers to a polyphyletic and very artificial group, the cell coverings of these organisms are very diverse in molecular composition and with different arrangements. Differences have taxonomic value since they allow microalgae phyla or even minor taxonomic groups, such as classes, orders or families, to be distinguished. Understanding the structure of cell coverings is also fundamental for the use of microalgae to obtain products of commercial value. Despite its importance, the composition and architecture of microalgae coverings is still poorly understood, especially considering the great diversity of organisms. Diatom frustules are the most studied coverings due their uses in areas of bio- and nanotechnology. There is a lack of information about the cell wall, lorica, periplast, amphiesma and scales. This study is a review with the aim of synthesizing literature information on microalgae cell coverings to describe their compositions, arrangements, functions and industrial uses.

Resumo em Inglês:

ABSTRACT Collema leptosporum was originally included in Collemataceae as part of the Collema fasciculare group, an informal group that also included C. fasciculare, C. papuanorum, and C. uviforme. However, molecular data from C. fasciculare showed that this species belongs to Arctomiaceae, and all species in this informal group were relocated to Arctomia, although no molecular data were generated and analyzed for C. leptosporum, C. papuanorum and C. uviforme. To investigate the phylogenetic relationships of Collema leptosporum, currently Arctomia leptospora, we analyzed three DNA loci and examined morphological and anatomical features of specimens collected near the type locality. Genetic data suggest that this species is not included in Arctomiaceae and should be treated as a new genus in Collemataceae. Hondaria gen. nov. is characterized by having the longest transversely-septate ascospores in the family ((100-)120-175(-200) × 2-4(-5) µm). This study also suggests that the structures characterizing the C. fasciculare group are a result of convergent evolution, since this group includes species from different distantly related species.

Resumo em Inglês:

ABSTRACT Red seaweed possess various sulfated polysaccharides (SPs) that could potentially be exploited as bioactive agents for medical and industrial applications. Crude polysaccharides from the red algae Corallina officinalis (SP1) and Pterocladia capillacea (SP2) were extracted and characterized according to their chemical content and their antioxidant, anti-inflammatory, anticoagulant, antibacterial, antifungal, and antifouling activities. The isolated polysaccharides contained low levels of protein and high levels of carbohydrate and sulfate. The extracted SPs were characterized by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectral data and revealed that SP1 is composed of carrageenan, while SP2 is composed of polysaccharides containing sulfated galactans plus κ- and ι-carrageenan. Both isolated SPs exhibited all the tested biological activities but those of SP2 were superior. These results reflect the beneficial effects that red algal polysaccharides have as a natural renewable bio-product and that there is a significant relationship between polysaccharide structure, sulfate content and their biological properties. Further studies should be undertaken on the fractionation and characterization of polysaccharides extracted from species of red seaweed in addition to experiments to verify the efficiency of the extracted SPs for food and medical uses in vivo.

Resumo em Inglês:

ABSTRACT The velamen, a root structure of some epiphytic species for water uptake, usually is stratified epidermis consisting of dead cells. In general, its cell walls exhibit variation during development, including in thickness and amount and type of impregnated substances. These changes result in diverse physical and chemical properties that can serve in water and nutrient uptake, as well as in mechanical support and protection. On this basis, the main objective of the current study was to describe the composition of the cell walls of the velamen during the development of the roots of four species of Cattleya. Anatomical, histochemical and immunocytochemical analyses were performed with samples (n=3 individuals per species) of meristematic, developing, and mature regions of the root. The development of the primary wall led to the deposition of pectins as highly methylesterified homogalacturonans, which were demetihylesterified with maturation of the velamen. The deposition of lipids (and subsequently lignins) in velamen cells marked a transition stage to the formation of the secondary wall, which gives rigidity to the tissue. For the first time, we showed that the deposition of lipids and lignins began close to the exodermis in the direction of the epivelamen.

Resumo em Inglês:

ABSTRACT Understanding how multiple drivers shape plant community diversity across environmental gradients is one of the most important issues in plant ecology and biodiversity conservation. We aimed to analyse plant community structure and diversity in four inselbergs in Espírito Santo State, Brazil. We evaluated species diversity, floristic composition and similarity, phytosociological structure, occurrence, and conservation status of rupicolous flora in the inselberg communities. We used field expeditions and plant inventory data from 370 sampling units. We estimated floristic similarity and compared diversity indexes among inselbergs. We observed marked differences in community structure and diversity among inselbergs, where the southern region had the highest number of taxa and higher values of diversity indices. There were also notable differences in floristic composition and phytosociological structure, with a decrease in similarity as geographical distance increased. This finding demonstrated the existence of differences in the patterns of dominance and vegetation cover along the latitudinal gradient, as well as differences in endemic, threatened, and exclusive species, and represents a first step toward establishing criteria for biodiversity conservation for inselbergs in Espírito Santo State.

Resumo em Inglês:

ABSTRACT Global change and coastal eutrophication are affecting macroalgae worldwide. We analyzed the effects of increased water temperature (25, 28 and 32 °C) and eutrophication on the growth of Bostrychia binderi and Bostrychia montagnei in a range of salinities (18, 24, 30, 36 and 42 PSU) through three independent multifactorial experiments. Both species had higher growth at 25 °C than at 28 and 32 °C (warming scenario projected by IPCC), suggesting a negative effect of ocean warming. The species showed a broad tolerance to the range of salinities tested, with higher growth at 36 and 42 PSU, as a local adaptation strategy. Oligotrophic seawater significantly affected the growth of both species because the lowest growth was found in this condition, whereas highest growth was found with increased availability of nutrients, which is probably because estuaries are nutrient-rich environments due to continental runoff. High temperatures, low salinities and few nutrients had negative interactive effects on the growth of both species. Our results show that ocean warming can be detrimental to the studied macroalgae, and that both species are tolerant to eutrophication, with B. montagnei being more sensitive than B. binderi. Our results also reinforce the euryhaline characteristic of the genus Bostrychia.

Resumo em Inglês:

ABSTRACT Although karyotype features are useful data for evolutionary studies, cytogenetic data in Bambusoideae are mainly based only on chromosome counts. The first comparative cytogenetic analysis of three Neotropical woody bamboo species - Guadua chacoensis, G. angustifolia and Chusquea tenella - was undertaken based on new and reviewed chromosome counts, CMA/DAPI double staining, fluorescent in situ hybridization (FISH) with 35S and 5S rDNA probes, and genome size estimation. The two species of Guadua were found to have 2n = 46 chromosomes, while the first record for C. tenella was 2n = 44. Only one pair of CMA+/DAPI- was detected on the terminal region of metacentric chromosomes in all three species. Likewise, one pair of 5S and 35S rDNA sites was detected in all three species, with the 35S rDNA sites always collocated with the CMA+ bands. Genome sizes ranged from 2C ≈ 3.99 pg for the species of Guadua, to 2C = 4.77 pg for C. tenella. Considering the Miocene origin of Neotropical woody bamboos, the observed karyotype stability suggests that the analyzed species are diploidized paleopolyploids. The results reveal the conservative cytomolecular organization of Neotropical woody bamboo karyotypes, which helps to improve our understanding of the evolution of this group.

Resumo em Inglês:

ABSTRACT Growth rings have been reported for several tropical species under seasonal precipitation regimes and have often been related to leaf phenology. We investigated growth ring distinctiveness, wood markers, and leaf shedding and flushing patterns of 16 tree species from a subtropical seasonal deciduous forest under abundant and well-distributed rainfall regime in southern Brazil. Distinct growth rings were found in 13 species, 10 of which presented clear anatomical boundaries. Seven species were deciduous, five semideciduous and four perennial. Leaf shedding peaked during winter and spring months for the deciduous species, while it peaked during spring and summer months for the perennial and semideciduous species. Leaf flushing peaked in spring and summer for all species. All the deciduous species exhibited growth rings with clear boundaries. Marginal parenchyma, associated or not with other anatomical markers, was present in deciduous species but was not present in species with other leaf shedding patterns. Growth rings in Allophylus edulis, Erythrina falcata, Jacaranda micrantha and Luehea divaricata were described for the first time. The presence of seasonal leaf phenological patterns and growth rings in most of the species suggests that seasonality of the photoperiod and/or temperature influence the development of trees in moist subtropical seasonal deciduous forests.

Resumo em Inglês:

ABSTRACT Ecological restoration by direct seeding in the Cerrado biome still lacks information about native species germination, the need for dormancy overcoming and seed bank formation. This study aims to verify the effects of dormancy overcoming on germination of four tree species and the ability of 12 tree species to form seed banks for restoration use. Our results showed wide variation of species’ germination rates. Overcoming dormancy enhanced germination for Dimorphandra mollis, Hymenaea stigonocarpa, and Peltophorum dubium and decreased it for Copaifera langsdorffii, but was only cost-effective for H. stigonocarpa. Regarding the ability to form seed banks, only H. stigonocarpa and Cecropia pachystachya germinated and live seedlings of Terminalia corrugata were found after being buried for six months, thus forming a transient seed bank. Despite the fact that overcoming dormancy may optimize germination after direct seeding, maintaining dormancy mechanisms of species that can form seed banks could be essential for species establishment over time in restoration areas. Hence, our key decision criteria based on seed costs and seed and labor availability would be useful for the seeding actions of restoration practitioners.

Resumo em Inglês:

ABSTRACT The diversity of endophytic fungi in healthy coconut palm leaves (Cocos nucifera) was assessed by analyzing fungal isolates from three coconut cultivars (yellow dwarf, green dwarf, and a hybrid cultivar PB121) used agriculturally in Brazil. The influence of season (rainy or dry) on the endophytic fungal community was also analyzed. Overall, 318 fungal isolates were obtained from 972 coconut leaf fragments. The rDNA ITS region was sequenced from representative species of the isolated endophytic fungi and the most common species identified were Nigrospora oryzae, Pestalotiopsis sp., and Zasmidium musae. The alpha diversity of the endophytic fungi was also calculated. Nonmetric multidimensional scaling (NMDS) ordination and permutational analysis of variance (PERMANOVA) revealed significant seasonal effects on the composition of the endophyte community. However, practically no influence was observed on the fungal communities for the different cultivars of coconut.

Resumo em Inglês:

ABSTRACT Dicksonia sellowiana is the only species of the genus occurring in Brazil. Its distribution is restricted to humid areas of the Atlantic Forest biome. The distribution pattern of biodiversity in this biome is known to have been influenced by historical and environmental factors, although the pattern for ferns remains unknown. This study is first to describe the genetic structure of D. sellowiana along the latitudinal gradient of the Atlantic Forest biome. We use microsatellite markers to estimate genetic diversity and structure for 267 individuals representing 14 populations of D. sellowiana from the Atlantic Forest. The results (Ho, He, Fst, Fis, distance genetic) support the hypothesis of a pattern of biodiversity discontinuity. We found greater genetic variability in populations located in regions of higher humidity and milder temperatures. Our data suggest that there is a clinal distribution pattern of genetic variation along the north to south latitudinal gradient of the Atlantic Forest. This clinal variation has a genetic basis in the frequencies of the two genetic groups. This structure does not evidence long-standing historical barriers to gene flow and favors the influence of landscape characteristics on the establishment of populations.

Resumo em Inglês:

ABSTRACT Among the recently discussed evolutionary issues on medical systems, one of the most controversial issues is the replacement of local medical systems with the biomedical system. Our study investigates the hybridization of two medical systems and the role that the perception of incidence and severity of diseases has in memorization and transmission of information about their treatments. We collected data from a rural population in Brazil during two different periods separated by eight years and compared the periods for changes according to the knowledge on treatments with drugs in the biomedical system and according to the incidence and severity of the diseases. We found 147 medicinal plants belonging to 58 botanical families. Our results show that biomedical and local systems complement each other and change over time for the cure of recurrent, instead of the most severe, events. We suggest that based on cultural biases, biomedical and local knowledge can coexist by complementing each other with regards to the range of resources used for healthcare, and that disease perception can guide the evolutionary path of medical systems. Our findings can help elucidate new biases that guide the evolution of medical systems and reinforce important issues in the healthcare literature.

Resumo em Inglês:

ABSTRACT South Brazilian grasslands are among the most species-rich grasslands worldwide yet they have been suffering ongoing degradation due to land-use. Little is known about the reproductive ecology of the native species of these grasslands. Thus, our goal was to characterize seed traits and germination requirements of three native species of the tribe Tigridieae (Iridaceae, Iridoideae) due to its richness in the Pampa biome and the contrasting morphology, cytogenetics, and geographic distributions of its representatives. We tested if closely related species possess similar seed traits and whether species with wider distributions have broader germination requirements. Seed production and mass were estimated, and morphological analyses, germination experiments and viability tests were performed. Principal component analysis (PCA) was used to describe correlations between seed traits and species’ distributions. Germination was assessed using time-to-event analysis and the Cox model. All seed traits differed among the analyzed species/cytotypes. Final germination percentage (FGP) averaged 39.1 % and with overall viability of 89.9 %. Germination tests showed that seeds benefit from negative photoblasty. Species/cytotypes with wider distributions and heavier and larger seeds generally had better germination performances than narrower distributed species/cytotypes with lighter and smaller seeds.

Resumo em Inglês:

ABSTRACT We characterized taxonomic and functional differences between two vegetation physiognomies in the Brazilian Chaco, namely chaco woodland (CW) and chaco forest (CF), in order to understand which abiotic and biotic mechanisms underlie the establishment of different physiognomies. We characterized the vegetation physiognomies by comparing woody species composition, richness and diversity and functional diversity between CW and CF plots. We also measured soil variables to characterize abiotic factors related to the different physiognomies. Species richness and diversity and soil nutrient values were higher in CF. Leaf succulence and nitrogen content were higher in CW, while height, leaf area, and specific leaf area were higher in CF. The standardized effect size (SES) of functional richness was higher in CW, but the SES of functional dispersion did not differ between CF and CW. We observed a diversity gradient related to soil fertility. Traits of species in CW were related to adaptations to poor soils, while in CF floristic composition showed a prevalence of species with more attributes related to competition for light. Thus, the structure of the floristic community in CW is likely related to an environmental filter, while competition for resources prevails in CF.

Resumo em Inglês:

ABSTRACT Plants harbour diverse communities of fungal species in their internal compartments. Endophytic fungi help their hosts to establish, survive, and adapt to different environments. Here, we examined the diversity of endophytic fungi in the leaflets and branches of Poincianella pyramidalis, a plant species endemic to the Brazilian tropical dry forest (Caatinga). A total of 360 fragments of leaflets and branches were analysed and 189 endophytic fungi were isolated and distributed among 21 ascomycetous genera based on their ITS and LSU rDNA sequences. Diaporthe was the most frequently identified genus, followed by Didymella and Rhytidhysteron. The colonisation rate of plant fragments was higher in the branches (74 %) than in leaflets (14 %). The richness of the genera of endophytic fungi was also higher in the branches than in leaflets, whereas no difference was observed in endophyte diversity between the plant parts, based on Shannon-Wiener and Fisher alpha diversity indices. Our results indicate that endemic plant species from Brazilian dry forest, such as P. pyramidalis, are predominantly colonised by ascomycetous fungi, especially members of the class Dothideomycetes.

Resumo em Inglês:

ABSTRACT Cereus hildmannianus K. Schum is a columnar cactus native to South and Southeast Brazil. The cultivation of this species seems justifiable for several reasons: its fruits are spineless and edible; it is not threatened with extinction; it naturally occurs in Pampa and Atlantic Forest under non-xeric conditions that may be unsuitable for the cultivation of other tropical cacti; and the plants are pollinator-dependent and so should benefit from native pollinators. This study aimed to test seed germination of C. hildmannianus with samples collected at three different localities in southern Brazil, as a necessary step preceding any attempts of management and domestication. Seeds were exposed to temperatures of 20° C, 25° C, 30° C and room temperature. The germinability, average germination time and synchronization index were calculated. All samples showed higher germinability at 20° C and 25° C. Seeds from Caçapava do Sul and Santiago showed significant variation in the synchronization index at 25° C and 30° C, respectively. Seeds from Porto Alegre had maximum germinability, indicating greater vigor. Our results show that the seeds of C. hildmannianus germinate well and thrive within a wide range of temperatures and that cultivation of the species from seed-raised plants should not be problematic.

Resumo em Inglês:

ABSTRACT The genus Manihot Mill. contains about 120 species of which about 104 occur in Brazil. We tested the cross-amplification of ten microsatellite markers developed for Manihot esculenta in 15 species of Manihot endemic to the Brazilian Cerrado. We also evaluated the genetic diversity of Manihot irwinii, M. orbicularis, and M. purpureocostata. Ten pairs of primers were amplified among 14 species of Manihot. The percentage of polymorphic loci per species varied from 70 to 100 %. Nine markers showed amplification and polymorphism when evaluated on polyacrylamide gel. The markers were combined to form three sets for multiplex genotyping for genetic diversity analysis, and showed 51, 75, and 75 alleles in M. irwinii, M. orbicularis, and M. purpureocostata, respectively. The levels of genetic diversity for the transferred markers were high for the three species and proved to be useful for population genetics studies of species of Manihot endemic to the Cerrado. The results of this study will help to better understand the genetic diversity, taxonomy and relationships among species Manihot, and to develop conservation programs for the genus.

Resumo em Inglês:

ABSTRACT As part of an ongoing study of the taxonomy and systematics of Rubiaceae of the state of Ceará, Brazil, a new species, Faramea baturitensis, is here recognized, described, and illustrated. The new species occurs in “Serra de Baturité,” a relic of the Atlantic Forest. Detailed data on the distribution, habitat, phenology, and conservation status of the new species, as well as a key to species of Faramea in Ceará, are provided.

Resumo em Inglês:

ABSTRACT After a brief historical account of the genus, a new species, Marsypianthes tubulosa, from the Brazilian state of Tocantins is described and illustrated. The new species is similar to M. chamaedrys (Vahl) Kuntze, the most polymorphic species of the genus. It is distinguished from the other species of the genus by its habit and characters of the cyme, calyx and corolla. Comments on the taxonomy and distribution of the new species are provided, as well as a conservation assessment, distribution map, photographs and a black and white illustration.

Resumo em Inglês:

ABSTRACT A new species of Buchnera (Orobanchaceae) from Northeast Brazil is described and illustrated. Buchnera nordestina was first collected by Dr. Francisco Freire Allemão e Cysneiro ca. 160 years ago and remained undescribed until now. We provide notes on morphology, geographic distribution, and conservation status of the new species. Additionally, we present an updated identification key to all species of Buchnera from Brazil. Buchnera nordestina is characterized by long bracts that are usually two times longer than the calyx tube and by the presence of axillary brachyblasts, both of which are unique features within the genus. The new species occurs in restinga and cerrado vegetation in the Brazilian states of Ceará, Maranhão, and Piauí, and is assessed as Endangered (EN).

Resumo em Inglês:

ABSTRACT As primary decomposers of organic matter, mucoralean fungi have an important ecological role in edaphic systems in the Atlantic Forest. However, there is a knowledge gap regarding how communities of Mucorales are structured in soils of Atlantic Forest areas, and whether these communities are influenced by edaphic attributes in this domain. Thus, the current study aimed to understand the influence of edaphic attributes linked to species richness, abundance and composition of Mucorales in dense ombrophilous forest, ‘tabuleiro’ forest, sandbank and mangrove ecosystems located in Pernambuco, Brazil. Altogether, twenty-three taxa, including seven new records, were reported from soil samples from the ecosystems. Species composition was similar among the ecosystems, except for mangrove, while species richness and diversity of Mucorales were highest in dense ombrophilous forest and ‘tabuleiro’. Together the soil variables were responsible for 35.5 % of the variation in species composition, with pH being responsible for 53.32 % and 47.24 % of the variation in richness and abundance of these communities, respectively. These data indicate that pH is the most important attribute in delimiting the structure of mucoralean communities in the study areas, with influence on the composition, richness, and abundance of these fungi.