Showing papers in "Brazilian Journal of Botany in 2008"
TL;DR: There is technical basis to consider cypsela and achene as different types of fruits in Asteraceae, and the existence of arguments to justify the adoption of a term against the other is verified.
Abstract: The worry about the indiscriminate use of the terms cypsela and achene for the fruits of Asteraceae has been frequently detached by specialists in this family. The present work was developed aiming to verify the existence of arguments to justify the adoption of a term against the other. After historical and anatomical analysis, we concluded that there is technical basis to consider cypsela and achene as different types of fruits. For Asteraceae, the correct is to call cypsela; achenes are only derived from superior ovaries, as in Plumbaginaceae.
TL;DR: In this article, the influence of soil properties on plant species abundance at two sites of ferruginous "campos rupestres" and one site of quartzitic "campo rupstre", all of them in "Quadrilatero Ferrifero", in Minas Gerais State, southeastern Brazil.
Abstract: Ferruginous "campos rupestres" are a particular type of vegetation growing on iron-rich primary soils. We investigated the influence of soil properties on plant species abundance at two sites of ferruginous "campos rupestres" and one site of quartzitic "campo rupestre", all of them in "Quadrilatero Ferrifero", in Minas Gerais State, southeastern Brazil. In each site, 30 quadrats were sampled to assess plant species composition and abundance, and soil samples were taken to perform chemical and physical analyses. The analyzed soils are strongly acidic and presented low fertility and high levels of metallic cations; a principal component analysis of soil data showed a clear segregation among sites due mainly to fertility and heavy metals content, especially Cu, Zn, and Pb. The canonical correspondence analysis indicated a strong correlation between plant species abundance and soil properties, also segregating the sites.
TL;DR: The species accumulation curve is unsuitable to determine optimum sample size in tropical forests because these curves do nothave as expected, and the concept of sampling sufficiency itself rests upon a problematic definition of plantcommunity.
Abstract: The use of the species-area relationship, or the accumulation species curve, to determine sampling sufficiency in phytosociological studies is a current technique, despite of being a controversial issue. The definition of an optimum sample size is based on the idea that the larger the sample size, the greater the number of species in the sample, but the rate of increase becomes progressively smaller so the curve tends to a flat line. The point where the curve becomes horizontal is the minimal area to represent the plant community: the sampling sufficiency. This concept assumes that the plant community is a spacially discrete entity with fixed species composition. In tropical forests, the identification of communities boundaries is particularly difficult and, due to their high species richness, the species accumulation curves do not become flat, even with large sample sizes. The species accumulation curve is unsuitable to determine optimum sample size in tropical forests because these curves do not behave as expected, futhermore the concept of sampling sufficiency itself rests upon a problematic definition of plant community.
TL;DR: The correlations between similarity matrices based on species in different vegetation strata and taxonomic groups were generally low and there was little correlation between matricesBased on quantitative data and matricesbased on presence/absence.
Abstract: (recebido: 22 de dezembro de 2005; aceito: 03 de marco de 2008) ABSTRACT - (Floristic composition and vegetation cover of the savannas in the "Alter do Chao" region, Santarem - PA) In this study, we determined the floristic composition in 38 plots of 3.75 ha (250 m x 150 m) distributed throughout 30.000 ha of savannas of "Alter do Chao", Santarem Municipality. Our surveys revealed 130 species in 45 families. The only species of dicotoledons that covered 1% or more of the area in the herb-shrub layer were Dioclea bicolor Benth. and Lafoensia pacari A. St.-Hil. Most of the area was covered by the grasses Paspalum carinatum Humb. & Bonpl. ex Flugge (16%) and Trachypogon plumosus (Humb. & Bonpl. ex Willd.) Nees (22%). The grass Axonopus canescens (Nees ex Trin.) Pilg. and the sedge Rhyncospora hirsuta Vahl also covered slightly more than 1% of the area. Only eight species, Anacardium occidentale L., Himatanthus fallax (Mull. Arg.) M. M. Plumel, Lafoensia pacari A. St.-Hil., Byrsonima coccolobifolia Kunth, Byrsonima crassifolia (L.) Kunth, Pouteria ramiflora (Mart.) Radlk., Qualea grandiflora Mart. and Salvertia convallariodora A. St.-Hil. had canopies in the tree layer which projected over more than 1% of the area. Of these, only B. crassifolia (5.7%), S. convallariodora (6.0%) and P. ramiflora (2.1%) projected over more than 2% of the area. Most of the area (mean = 53%) did not have any grass, bush or sedge cover and 45% also had no tree-canopy cover. Grasses and sedges covered a mean of 39.2% of the plots, and shrubs 11.0%. The correlations between similarity matrices based on species in different vegetation strata and taxonomic groups were generally low and there was little correlation between matrices based on quantitative data and matrices based on presence/absence. Therefore, caution should be exercised in comparisons among savanna areas based on only one vegetative stratum or on only one taxonomic group. RESUMO - (Composicao floristica e cobertura vegetal das savanas na regiao de Alter do Chao, Santarem - PA). Neste estudo foi determinado a cobertura vegetal e a composicao floristica em 38 parcelas de 3,75 ha (250 m x 150 m), distribuidas por 30.000 ha na savana de Alter do Chao, Municipio de Santarem, Para. Nas 38 parcelas foram registradas 130 especies em 45 familias. As unicas especies de dicotiledoneas que cobriram 1% ou mais da area no estrato herbaceo-arbustivo foram Dioclea bicolor Benth. e Lafoensia pacari A. St.-Hil. A maior parte da area foi coberta pelas gramineas Paspalum carinatum Humb. & Bonpl. ex Flugge (16%) e Trachypogon plumosus (Humb. & Bonpl. ex Willd.) Nees (22%). A graminea Axonopus canescens (Nees ex Trin.) Pilg. e a ciperacea Rhyncospora hirsuta Vahl tambem cobriram mais que 1% da area. Apenas oito especies, Anacardium occidentale L., Himatanthus fallax (Mull. Arg.) M. M. Plumel, Lafoensia pacari A. St.-Hil., Byrsonima coccolobifolia Kunth, Byrsonima crassifolia (L.) Kunth, Pouteria ramiflora (Mart.) Radlk., Qualea grandiflora Mart. e Salvertia convallariodora A. St.-Hil. tinham copas no estrato arboreo que projetaram sobre mais que 1% da area. Destas, somente B. crassifolia (5,7%), S. convallariodora (6,0%) e P. ramiflora (2,1%) projetaram sobre mais que 2% da area. Cinquenta e tres por cento da area nao tinha cobertura de arbustos, gramineas ou ciperaceas, e 45% tambem nao tinha cobertura de copas de arvores. Gramineas e ciperaceas cobriram em media 39,2% das parcelas, e arbustos 11,0%. As correlacoes entre matrizes de similaridade para as especies em diferentes estratos e grupos taxonomicos da vegetacao foram geralmente baixas e houve pouca correlacao entre matrizes baseadas em dados quantitativos e matrizes baseadas em dados de presenca/ausencia. Portanto, deve-se ter cautela em comparacoes entre areas de savana baseadas somente em um estrato vegetativo ou em um grupo taxonomico.
TL;DR: The reproductive biology of Dipteryx alata was studied and the increasing of seed production in natural populations of D. alata depends on the maintenance of effective pollinators (solitary bees), and it is recommended the management of A. mellifera.
Abstract: The reproductive biology of Dipteryx alata was studied from September/2004 through August/2006. Dipteryx alata is a tree that blooms during the rainy season (4-6 months) and fructification peak occurs in the dry season. There are annual variations in the intensity of flowering and fructification. The flowers are zygomorphic, papilionaceous, hermaphrodite, relatively small, odoriferous, diurnal and last up to 10 hours. The calyx has two petaloid lobules and the corolla is formed by the standard, wings and the petals of the keel. Pollen viability is 94.4%. The stigma is covered by a pelicule that prevents pollen adherence and limits the spontaneous self-pollination. Nectar is produced in a chamber, in small quantity (1.45 µL) and with concentration of 25%. Dipteryx alata has keel flowers and the mechanism of pollination is intermediate between the explosive and valvular types. This species is alogamous, has late acting self-incompatibility and high rate of abortion (ER = 0.45). The main pollinator is Xylocopa suspecta (16.6% of visits), which visits legitimately the flowers and presents trap lining behavior, that promotes pollen flow between plants. Although the visitation rate of Pseudaugochlora graminea (15.3%) and Apis mellifera (39.5%) bees are relatively high, they are not good pollinators (pollination efficiency = 3.5 and 0, respectively), because they generally did not accomplish movement between plants. Apis mellifera robbed nectar in 45.5% of visits. The increasing of seed production in natural populations of D. alata depends on the maintenance of effective pollinators (solitary bees), and it is recommended the management of A. mellifera.
TL;DR: The objective of this work was to study the morphology and secretory products of glandular trichomes of Cordia verbenacea DC, known as 'baleeira', a species used in folk medicine as anti-inflammatory, analgesic, anti-ulcerogenic and healing agent.
Abstract: The objective of this work was to study, using light and fluorescence microscopy and scanning electron microscopy, the morphology and secretory products of glandular trichomes of Cordia verbenacea DC. (Boraginaceae), known as 'baleeira', a species used in folk medicine as anti-inflammatory, analgesic, anti-ulcerogenic and healing agent. Two classes of glandular trichomes were recognized, globular and reniform. A morphological study of the secretory head and the characterization of the secretory product are also presented. Secretory products of globular trichomes consisted of essential oils, whereas reniform trichomes consisted basically of phenolic compounds such as flavonoids. No pre-established regions for releasing secretory products were found.
TL;DR: In this paper, the effect of an altitudinal gradient on the floristic composition and vegetation structure of upper montane forests was analyzed, and the structural parameters maximum canopy height and number of branched individuals were correlated with altitude.
Abstract: The upper montane forests are known to have a different floristic composition and phytosociological structure from forests located at lower altitudes. A survey was carried out in an area of upper montane forest of the Mantiqueira Range near Monte Verde, municipality of Camanducaia, Minas Gerais State, Brazil. The main objective of this study was to analyze the effect of an altitudinal gradient on the floristic composition and vegetation structure. Seven blocks, each with five of 10 × 10 m plots, were located at altitudes ranging from 1,820 m to 1,940 m, and all bamboos and trees with GHB >15 cm were sampled. A total of 1,191 individuals were included, belong to 64 tree species and two bamboos in a total of 42 genera and 26 families, including the standing dead individuals. The estimated density was 3,403 ind ha-1 and the value of the Shannon-Wiener (H') index was 3.284 nat ind-1. The dead biomass had the highest importance value (42.06), followed by Pimenta pseudocaryophyllus (Gomes) Landrum (24.59), Roupala rhombifolia Mart. ex Meisn. (19.98) and Drimys brasiliensis Miers (18.57). The structural parameters maximum canopy height and number of branched individuals were correlated with altitude. Although the altitudinal gradient is relatively short, a considerable degree of species substitution was observed, leading to a well-marked floristic gradient.
TL;DR: Characterizing the non-arboreal phanerogamic flora occurring in distinct "cerrado" vegetation types at Assis Ecological Station indicates that either endemism can be higher among these life-forms than among arboreal species or inventory methods were not adequate to survey the total richness of the studied areas.
Abstract: A vegetacao de cerrado no Estado de Sao Paulo sobrevive em poucas areas naturais remanescentes cuja flora, exceto pelas especies arboreas, e pouco conhecida. O presente estudo teve como objetivo caracterizar a flora fanerogâmica nao-arborea das diferentes fisionomias da vegetacao (campo umido, cerrado sensu stricto, cerradao e mata ciliar) na Estacao Ecologica de Assis (22°33'65" e 22°36'68" S e 50°22'29" e 50°23'00" W), Estado de Sao Paulo, Brasil, e compara-la a outras areas de cerrado no estado, para verificar possiveis endemismos ou a presenca de especies raras, que merecam providencias especiais de manejo para sua conservacao. Nas diferentes fisionomias da vegetacao no interior da unidade de conservacao foram registradas 301 especies fanerogamas nao-arboreas, pertencentes a 199 generos e 61 familias. As familias com os maiores numeros de especies foram: Fabaceae, Asteraceae, Bignoniaceae e Poaceae. A riqueza de especies foi decrescente do cerrado sensu stricto (146 especies ou 48,8%), seguido pelo cerradao (48 especies ou 15,9%), campo umido (47 especies ou 15,6%) e, por ultimo, a mata ciliar (15 especies ou 5,0%). Comparada as outras areas analisadas de cerrado no Estado de Sao Paulo, a diversidade da flora nao-arborea local e elevada. O alto nivel de ocorrencias unicas para as formas de vida inventariadas (102 especies ou 34%) tem sido igualmente observado em outros estudos, indicando que ou os endemismos sao mais comuns para especies vegetais nao-arboreas do que para arboreas ou os metodos de inventario nao tem sido adequados para representar toda a riqueza dessas especies em cada local. Estrategias de conservacao e inventarios botânicos devem valorizar especialmente a flora nao-arborea, uma vez que as especies da flora arborea apresentam-se mais amplamente distribuidas e melhor inventariadas.
TL;DR: In this article, the authors investigated the dynamics of the shrub-tree component in an alluvial gallery forest in Pocos de Caldas, Minas Gerais, from 1998 to 2005.
Abstract: The dynamics of the shrub-tree component was investigated in an alluvial gallery forest in Pocos de Caldas, Minas Gerais, from 1998 to 2005. The main objective of this study was to verify if the rates of the dynamics of the alluvial gallery forests are less than other tropical riparian forest formations. Seasonal flooding was also studied to see if it generates a spatial variation in the dynamics of going from the stream side towards the forest border. The sample consisted of 101, 10×10-meter plots that were distributed in five blocks extending approximately 8 km along the Antas River's forest. Each block was divided into three sectors (stream side, forest interior, and forest edge). Compared with other tropical forests, especially the riparian ones, this forest showed lower rates in terms of structural alterations. The forest edge is more dynamic, mainly due to the greater amount of sunlight, which supplies an adequate environment for species with a short life cycle.
TL;DR: Although the forest has disturbed areas there are patch of relatively mature vegetation, thus this area is essential for biodiversity conservation and tree species comparison with 25 forests from Sao Paulo State and northern Parana State showed that the reserve flora is more similar to forests from Campinas region.
Abstract: O inventario floristico de um fragmento de floresta semidecidua foi conduzido durante o periodo de maio de 1996 a abril de 1998 em um hectare de floresta localizado na regiao central da Reserva de Santa Genebra (22o49'45" S e 47o06'33" W) a 580-610 m de altitude. Foram identificadas 201 especies, distribuidas em 57 familias e 147 generos. Fabaceae e Rubiaceae (18 especies), Myrtaceae (14 spp.), Rutaceae (11 spp.), Solanaceae e Sapindaceae (nove spp.), Bignoniaceae, Meliaceae e Euphorbiaceae (oito spp.), Malvaceae (sete spp.) foram as familias mais ricas. Cerca de 70% das especies foram classificadas como secundarias tardias e secundarias tardias de sub-bosque. A comparacao de especies arboreas com 25 fragmentos do Estado de Sao Paulo e Norte do Parana mostraram que a flora da reserva e mais similar as florestas da regiao de Campinas. Embora a floresta apresente areas perturbadas, existem manchas de vegetacao relativamente maduras sendo esta area essencial para a conservacao da biodiversidade.
TL;DR: Pollen viability of Carica papaya L. papaya cultivar 'Sunrise Solo' cultivar was estimated using in vitro germination and pollen stain tests and the five stains overestimated pollen viability, and their use should be restricted to determining cell constituents, and pollen grain integrity.
Abstract: Pollen viability of Carica papaya L. 'Sunrise Solo' cultivar was estimated using in vitro germination and pollen stain tests. Two culture media described in the literature as efficient for pollen in vitro germination of C. papaya were used. Germination was higher in the media without essential elements but with a higher concentration of agar (65% compared with 51.5%). These results were compared with viability estimates based on staining pollen. The five stains used to test for pollen viability were: 2,3,5-triphenyl tetrazolium chloride - TTC, Alexander's stain, acetocarmine, iodine-potassium iodide and Sudan IV. Pollen viability estimated with TTC was 67.5% and similar to germination results providing a reliable estimate of in vitro germination. The four other stains overestimated pollen viability (> 90%), and their use should be restricted to determining cell constituents, and pollen grain integrity.
TL;DR: Estate trabalho sao discutidas algumas medidas utilizadas para estimar sincronia e proposto um novo indice, o qual inclui a duracao total da fenofase de certo individuo e a variacao na quantidade of flores e frutos neste intervalo de tempo.
Abstract: The degree of flowering and fruiting synchronization is believed to have ecological and evolutionary relevance at several scales. Here we discuss some measures that have been used to estimate synchrony and propose an index that incorporates both the entire length of an individual phenophase and variation in the number of flowers or fruits over that time period. This new index describes more accurately the phenological synchrony among individuals and populations.
TL;DR: It is demonstrated that recalcitrant seeds of Inga vera subsp.
Abstract: Recalcitrant seeds are intolerant to both desiccation and low temperatures, the most important mechanisms of seed conservation, consequently their storage is difficult. Inga vera subsp. affinis produces the so-called recalcitrant seeds, since they do not survive to water content lower than 35%. In this work it is demonstrated that these seeds are tolerant to temperatures as low as -2 oC. Embryos of I. vera of different stages of maturity were stored at temperatures varying from 8 to -18 oC for until 45 days. Non-dried embryos and both dried to -4 MPa and -6 MPa were stored. Results showed that, despite all embryos died at -18 oC, some cold tolerance was obtained by mature embryos when stored at -2 oC, as long as they are dried to -4 MPa.
TL;DR: A formacao de embrioes somaticos anomalos, bem como a baixa taxa de seu desenvolvimento em plântulas (" emblings" ), refletiria a ocorrencia de disturbios fisiologicos e/ou geneticos protagonizada pela presenca de 2,4-D no meio of cultura.
Abstract: A embriogenese somatica representa uma ferramenta importante para estudos basicos do desenvolvimento das plantas. Atualmente este processo e utilizado como uma tecnica com potencial para a micropropagacao de plantas em grande escala, embora ainda com aplicacao restrita a poucas especies. Entretanto, quando sao formados embrioes somaticos anomalos a aplicacao economica e inviabilizada. Em Acca sellowiana (O. Berg) Burret, uma importante frutifera nativa, uma elevada quantidade de embrioes somaticos com fenotipos alterados (76,3%) foi encontrada ja no 40o dia de cultura na presenca de 2,4-D. Entre esses, 12,2% consistiam de embrioes fundidos, 40,4% apresentavam cotiledones concrescidos, 13% possuiam mais de dois cotiledones e 10,7% nao tinham cotiledones ou eles eram pouco desenvolvidos, incluindo os embrioes sem meristema apical caulinar. As analises histologicas mostraram que os embrioes malformados originavam-se tanto diretamente dos cotiledones, hipocotilo e radicula dos embrioes zigoticos utilizados como explantes, como indiretamente de calos formados a partir dessas estruturas. Sugere-se que a formacao de embrioes somaticos anomalos, bem como a baixa taxa de seu desenvolvimento em plântulas (" emblings" ), refletiria a ocorrencia de disturbios fisiologicos e/ou geneticos protagonizada pela presenca de 2,4-D no meio de cultura. Sao indicadas algumas abordagens experimentais alternativas visando reduzir a ocorrencia de embrioes somaticos com malformacoes.
TL;DR: As expected, forest fragmentation has caused a decrease in gene flow among the populations, especially between the most distant fragment, and an alternative to promote gene flowamong forest fragments of " Pontal do Paranapanema" would be the settle of agroforests, which would act as stepping-stones, favouring pollen and seed dispersion among fragments.
Abstract: The " Pontal do Paranapanema" is the most recently deforested region of the state of Sao Paulo in Brazil. The effects of forest fragmentation on the population genetic structure of Copaifera langsdorffii Desf. were evaluated by genotyping with six microsatellite loci at least 30 adult and 30 sapling individuals of three populations in " Pontal do Paranapanema" . The sampling areas comprised two fragments located in the rural settlements Tucano (800 ha) and Madre Cristina (300 ha); and one population located in a continuous forest, the " Parque Estadual do Morro do Diabo" (35,000 ha). High levels of genetic diversity were detected in saplings and adults, gene diversity (He) ranged from 0.718 to 0.835 and average number of alleles per locus (Â) ranged from 8.67 to 11.83, showing that the fragmentation has not caused loss of alleles yet. The high estimated fixation indexes (from 0.183 to 0.387) are due to null alleles in some loci and the occurrence of inbreeding within populations. Genetic divergence was low among adults (RST = 0.035) but increased among saplings (RST = 0.075). As expected, forest fragmentation has caused a decrease in gene flow among the populations, especially between the most distant fragment (Tucano - about 8 km from the " Parque Estadual do Morro do Diabo" ). An alternative to promote gene flow among forest fragments of " Pontal do Paranapanema" would be the settle of agroforests, which would act as stepping-stones, favouring pollen and seed dispersion among fragments.
TL;DR: The family Asteraceae as a species set was the main floral resource used by insect visitors through the year and has great importance for the maintenance of populations of many species of bees, flies, wasps and butterflies in the studied area.
Abstract: The goal of the present study was to identify plant species used as food source, the floral resources utilized, and the insects that visit flowers in a grassland community in southern Brazil. The study was carried out in an area of one hectare, located in a grassland formation in the Parque Estadual de Itapua, State of Rio Grande do Sul, Brazil. The flowering pattern was seasonal, and richness and abundance of insects was higher during the period of high resource availability. Flowers of 106 species of angiosperms (73 genera and 34 families) were used as source of floral resources for 219 species (2,767 specimens) of insects. A total of 91.5% of plant species were visited by bees, 53.8% by flies, 34.9% by wasps, 22.6% by butterflies, and 12.3% by beetles. Nectar was the main resource consumed by the visitors (41.1%). Asteraceae was the richest (38 spp.) and most visited family, with 63.1% of the species and 49.5% of all specimens of recorded insects. Bees were the most representative insects (33.2% spp., 65% indiv.), followed by flies (26.9% spp., 16.5% indiv.), wasps, butterflies and beetles. 40 plant species were considered important resources for the floral visitors' community, due to high number of, both, species and individuals recorded in their flowers. The family Asteraceae as a species set was the main floral resource used by insect visitors through the year and has great importance for the maintenance of populations of many species of bees, flies, wasps and butterflies in the studied area.
TL;DR: The results obtained revealed that the ontogeny, type, structure, and distribution of laticifers of the species of Asclepiadeae from "restinga", lowland humid forests, and "cerrado" vegetation are similar.
Abstract: Laticifers occur in all members of Apocynaceae. They are described as nonarticulated branched by most authors, but articulated laticifers have been reported to some species of this family. The present study aims to describe the laticifer ontogeny, structure, distribution, and type in vegetative organs of Fischeria stellata (Vell.) E.Fourn., Gonioanthela axillaris (Vell.) Fontella & E.A. Schwarz, Matelea denticulata (Vahl) Fontella & E.A. Schwarz, and Oxypetalum banksii Schult. and re-evaluate the laticifers of Asclepias curassavica L. from Atlantic rainforest, comparing the results with those of species from "cerrado" vegetation. The laticifers of these five species are articulated anastomosing, whose transverse or oblique walls dissolve rapidly and entirely. The laticifers branch through lateral anastomoses and form a continuous system throughout the adult plant. They are observed in primary tissues of stem and leaf, except in epidermis; they are also present in the secondary vascular tissue, except in the secondary xylem of A. curassavica. The ontogeny of these laticifers may explain the divergence between our data and those recorded for most species of the family. The results obtained revealed that the ontogeny, type, structure, and distribution of laticifers of the species of Asclepiadeae from "restinga", lowland humid forests, and "cerrado" vegetation are similar. The continuity of the articulated anastomosing laticifer system ensures a greater latex flow into the injured organ, releasing the laticifer exsudate simultaneously, coagulating and sealing the wounds rapidly, besides hindering the entrance of microorganisms.
TL;DR: The reproductive biology of Bauhinia curvula was studied in a " cerrado" fragment in Mato Grosso do Sul State, Brazil and it did not bear fruit after spontaneous self-pollination, probably due to pollen limitation.
Abstract: The reproductive biology of Bauhinia curvula was studied in a " cerrado" fragment in Mato Grosso do Sul State, Brazil. Bauhinia curvula is a shrub that blooms during six to seven months (July to November/December) and has a subterranean stem whith regeneration function. The flowers are white, hermaphrodite, zigomorphic, with nocturnal anthesis, they exhale unpleasant odor, and last about 11 hours. The stigma is wide and located above and/or in front of the anthers that presents pollen with 98.5% of viability. Nectar is produced in the hipanthium, with 26 µL medium volume and solute concentration around of 15%. Although flowers of B. curvula have several characteristics related to both chiropterophilous and sphingophilous syndromes, the small nectar volume and the narrow nectariferous chamber entrance seems to discourage bats visits. Bauhinia curvula is self-incompatible and depends on pollinators, therefore it did not bear fruit after spontaneous self-pollination. The studied population presented reduced reproductive effectiveness (0.07), probably due to pollen limitation. Agrius cingulatus (Sphingidae) was the only flower visitor which presents visiting behaviour, body size and proboscis length appropriated to effective pollination. This fact aid in a medium to long way the autogamic genotipe selection.
TL;DR: O presente estudo investigou aspectos da biologia floral, sistema reprodutivo e polinizadores de J.Jacaranda copaia (Aubl.) D. Don e uma arvore pioneira distribuida por toda Amazonia brasileira, encontrada colonizando clareiras, areas alteradas e bordas de fragmentos florestais.
Abstract: Jacaranda copaia (Aubl.) D. Don e uma arvore pioneira distribuida por toda Amazonia brasileira, encontrada colonizando clareiras, areas alteradas e bordas de fragmentos florestais. O presente estudo investigou aspectos da biologia floral, sistema reprodutivo e polinizadores de J. copaia. O florescimento ocorre de agosto a novembro, durante o periodo de menor precipitacao pluviometrica, estendendo-se por ate quatro semanas por individuo e tres ou quatro meses para a populacao, caracterizando um padrao de floracao cornucopia. A frutificacao termina no inicio da estacao chuvosa, com a dispersao anemocorica das sementes aladas. A taxa de frutificacao natural foi de 1,06% (n = 6.932). As flores autopolinizadas manualmente (n = 2.099) nao produziram frutos. A polinizacao cruzada (n = 2.524) resultou em 6,54% frutos, representando seis vezes mais do que a polinizacao natural (1,06%, n = 6.932). As flores protegidas da visita de polinizadores (autopolinizacao espontânea) nao formaram frutos (n = 5.372). O crescimento dos tubos polinicos foi detectado sob microscopia de fluorescencia tanto nos pistilos autopolinizados quanto nos submetidos a polinizacao cruzada. A especie foi considerada alogama obrigatoria, com mecanismo de auto-incompatibilidade de acao tardia. Aproximadamente 40 especies de abelhas nativas visitaram as flores, entretanto os polinizadores legitimos foram principalmente abelhas solitarias de medio porte dos generos Euglossa e Centris, em funcao da compatibilidade entre o tamanho corporal com o tubo da corola, que facilitava o contato direto com as estruturas reprodutivas, e a elevada frequencia de visitas.
TL;DR: The objective of this propagation study was to describe morphologically fruits, seeds and seedlings and define the "normal seedling" of E. schomburgki in order to provide important information for the development of seed technology.
Abstract: Enterolobium schomburgkii Benth. (orelha-de-macaco) e uma arvore de interesse madeireiro que possui potencial para plantios florestais em areas degradadas, por ser heliofila e nodulifera. Os objetivos deste trabalho foram caracterizar morfologicamente os frutos, sementes e plântulas e definir o estadio de desenvolvimento da "plântula normal" de E. schomburgkii, visando fornecer informacoes valiosas para a padronizacao dos estudos de propagacao da especie na area de tecnologia de sementes. O fruto e um legume nucoide, sublenhoso, polispermico, auriculiforme e circular, com as dimensoes de 21,2 × 3,2 cm para o legume estendido; e 6,2 ×5,9 ×0,5 cm para o fruto na forma original. O peso fresco de um fruto foi de 6,7 g, com 16,1 sementes sadias por fruto, sendo necessarios 62 frutos para obter 1.000 sementes sadias. O numero de sementes por quilograma foi de 18.749 e o peso de mil sementes foi de 53,6 g. A semente e elipsoide, de superficie lisa, brilhosa, marrom-amarelo escuro, com as dimensoes de 8,0 ×3,9 ×2,6 mm e peso de 0,054 g. O eixo embrionario e reto e visivel, com plumula bem desenvolvida. Observou-se que a germinacao e do tipo epigea fanerocotiledonar, com cotiledones foliaceos. A protrusao da raiz primaria foi de 95,7%, e para a formacao de plântulas normais foi de 80,2%. A "plântula normal" foi formada entre 7 e 15 dias apos a semeadura, possuindo raiz primaria bem desenvolvida, raizes secundarias curtas, hipocotilo alongado, cotiledones semi-abertos e primeiros eofilos visiveis, com o mesmo comprimento dos cotiledones.
TL;DR: Transmission Electron Microscopy displayed immature plastids from young mesophyll cells containing eletron-dense deposits similar to phenolic substances, suggesting that Theobroma plastid are involved in the synthesis of phenolics.
Abstract: The amount of cotyledon polyphenolic cells varies extensively within the Theobroma species. The polyphenolic compounds of these cells play a protective role and furthermore have an important function in the development of chocolate flavour. The morphology of the polyphenolic cells of the mesophyll is described and the development of these idioblasts in Theobroma cacao L., T. subincanum Mart., T. obovatum Klotzsch ex Bernoulli, T. grandiflorum (Willd. ex Spreng.) K. Schum., T. microcarpum Mart., T. bicolor Bonpl. and T. speciosum Willd. ex Spreng analysed. The total polyphenolic content in the seeds as determined by spectrophotometry showed a variation of about forty times. The alive, transparent polyphenolic cells are scattered throughout the cotiledonary mesophyll. However the polyphenolic cells of T. cacao and T. grandiflorum are also aligned perpendicularly with respect to the mesophyll borders and, in addition, both species display polyphenolic cells with a natural translucent purple colour. All the species analysed contained polyphenolic cells scattered throughout the parenchymal cells and also in a lengthwise association with vascular bundles. In T. bicolor and T. speciosum, the species with the lowest polyphenolic contents, these cells were mostly located around the vascular bundles. Using Scanning Electron Microscopy, the polyphenolic cells demonstrated a complex cytoarchitecture, and after fixing with glutaraldhyde, the polyphenolic secretion was shown to remain as a single unit or was organized into round droplets. Transmission Electron Microscopy displayed immature plastids from young mesophyll cells containing eletron-dense deposits similar to phenolic substances, suggesting that Theobroma plastids are involved in the synthesis of phenolics.
TL;DR: The comparison among six cerrado areas revealed great floristic heterogeneity since the similarity indexes produced low values, even among neighboring areas.
Abstract: Realizou-se o levantamento floristico de uma area remanescente de cerrado sensu stricto no Municipio de Botucatu, regiao centro-oeste do Estado de Sao Paulo, Sudeste do Brasil. Foram registrados 179 taxons de angiospermas (177 especies) distribuidas em 122 generos e 49 familias e cinco especies de pteridofitas pertencentes a quatro generos e duas familias. O componente lenhoso foi predominante representando mais de 60% das especies registradas. A proporcao das especies arboreas para as nao arboreas foi de 1:3. As familias com maior riqueza foram: Asteraceae (27 especies), Fabaceae (22), Myrtaceae (11). A comparacao entre seis areas de cerrado revelou grande heterogeneidade floristica uma vez que os indices de similaridade produziram valores baixos, mesmo entre areas proximas.
TL;DR: A mesophylly-to-xeromorphy gradient among the four vegetation types is detected, apparently associated to several environmental conditions, mainly soil characteristics and light intensity.
Abstract: This study investigated the leaf morphology of Miconia sellowiana, in four different vegetation types: Grassland (EGL), Montane Atlantic Forest (FODM), Upper Montane Atlantic Forest (FODAM), and Araucaria Forest (FOM), at the state of Parana, Brazil. Twenty leaves were selected from six individuals from each vegetation type. Several leaf parameters were analyzed including leaf area, leaf dry mass, specific leaf area (SLA), trichomes and stomata densities, and anatomical measurements. The leaves of M. sellowiana from EGL and FODAM presented pronounced xeric characteristics, with higher mean values for stomata density, trichome density on the adaxial surface, thickness of the cuticle of adaxial epidermis, spongy parenchyma, and total lamina thickness; and lower mean values for leaf area, dry leaf mass, and specific leaf area. The use of ANOVA and PCA detected a mesophylly-to-xeromorphy gradient among the four vegetation types: FOM>FODM>EGL>FODAM. The differences are apparently associated to several environmental conditions, mainly soil characteristics and light intensity.
TL;DR: The general patterns of patchy distribution and dominance by few species described for lotic macroalgal communities were corroborated by data from INP, suggesting that they seem to be universal for such communities.
Abstract: Itatiaia National Park (INP) includes two kinds of Brazilian vegetation within its limits: Atlantic tropical rainforest (AF) and highland grassland (HG). Fourteen sites were sampled, seven in each region (AF and HG), in two seasons (summer and winter). Twenty nine species of macroalgae were surveyed, from which 15 in AF and 19 in HG, with only five species in common. Species richness per sampling site ranged from 1 to 7 (2.9 ± 2.0), Shannon-Wiener diversity index (H') from 0 to 0.94 (0.24 ± 0.26) and percent cover from 0 to 35% (14.0 ± 12.5%). These values fitted within the range reported in previous studies on lotic macroalgae. Multiple regression analysis revealed that temperature variations accounted for 39.2% of abundance and 35.5% of species richness variations and also that 54.8% of diversity variations were explained by variations of Chemical Oxygen Demand (COD) and pH. Cluster analysis of macroalgal communities of INP did not group sites from the same regions (AF and HG). Principal Component Analysis clearly separated the sampling sites of the two regions, as well as of the two seasons (summer and winter), mostly influenced by temperature, shading, pH, altitude, potassium and COD. The general patterns of patchy distribution and dominance by few species described for lotic macroalgal communities were corroborated by data from INP, suggesting that they seem to be universal for such communities.
TL;DR: The most relevant quantitative characteristics diferentiating root wood from stem wood were: vessel elements length and frequency; fibre length, diameter and wall thickness; and ray width and height.
Abstract: Wood from stem and root of L. salviifolia Cham. (Verbenaceae) was studied. Three plants were sampled in a "cerrado" area in Pratânia municipality, Sao Paulo state (23o02'55,5" S e 48o31'26,1" W). Stem samples were collected at breast height (1.30 m from soil), and root samples were collected 30 to 40 cm from the stem base. There were qualitative and quantitative variations between root and stem wood. The most relevant quantitative characteristics diferentiating root wood from stem wood were: vessel elements length and frequency; fibre length, diameter and wall thickness; and ray width and height. Well defined growth increments were observed in root and stem wood. Simple and multiple perforation plates were observed in vessel elements in root and stem wood, however radiate plates were observed only in root wood. Septate fibres and wider rays were observed in root wood.
TL;DR: Experiments in captivity showed that scaly-headed parrots, toco toucans, jays, guans, and guans consumed the fruits and did not prey on the seeds before consumption, and the seeds collected from the feces did not germinate in spite of the high viability.
Abstract: Dehiscent fruits of Euphorbiaceae usually have two stages of seed dispersal, autochory followed by myrmecochory. Two stages of Margaritaria nobilis seed dispersal were described, the first stage autochoric followed by ornithocoric. Their dehiscent fruits are green and after they detached from the tree crown and fall on the ground, they open and expose blue metallic cocas. We studied the seed dispersal system of Margaritaria nobilis in a semi-deciduous forest in Brazil. In 80 h of focal observations, we recorded only 12 visits of frugivores, however the thrush Turdus leucomelas was the only frugivore that swallowed the fruits on the tree crown. Pitylus fuliginosus (Fringilidae) and Pionus maximiliani (Psittacidae) were mainly pulp eaters, dropping the seeds below the tree. On the forest floor, after fruits dehiscence, jays (Cyanocorax chrysops), guans (Penelope superciliaris), doves (Geotrygon montana) and collared-peccaries (Pecari tajacu) were observed eating the blue diaspores of M. nobilis. Experiments in captivity showed that scaly-headed parrots (Pionus maximiliani), toco toucans (Ramphastos toco), jays (Cyanochorax chrysops), and guans (Penelope superciliaris) consumed the fruits and did not prey on the seeds before consumption. The seeds collected from the feces did not germinate in spite of the high viability. The two stages of seed dispersal in M. nobilis resembles the dispersal strategies of some mimetic species. However M. nobilis seeds are associated with an endocarp, it showed low investment in nutrients, and consistent with this hypothesis, M. nobilis shared important characteristics with mimetic fruits, such as bright color display, long seed dormancy and protection by secondary compounds.
TL;DR: A survey of Habenaria in the Amazon region in northern Brazil found the greatest similarity is found with the "cerrado" of the centralwestern region and the Guianas, and only five species are common with the Atlantic Forest.
Abstract: A survey of Habenaria in the Amazon region in northern Brazil was undertaken. Forty species are recognized for the region. The majority of the species occur in savannah vegetation and the vegetation types with the highest number of species are the inland savannahs on terra firme (19 spp.), the savannahs of Roraima (16 spp.) and the coastal savannahs of Para and Amapa (15 spp.). Only four species grow in forest and three in the Amazonian caatinga. Nine of these species are restricted in Brazil to the Amazon region, four species from forest formations and three from highlands at the border with Venezuela. Only one species, H. sylvicultrix Lindl. ex Kraenzl., is possibly endemic to northern Brazil. When compared to other regions, the greatest similarity is found with the "cerrado" of the centralwestern region (28 spp. in common) and the Guianas (26 spp.). Only five species are common with the Atlantic Forest. Five species are recorded for the first time or confirmed in Brazil: H. avicula Schltr., H. dentifera Schweinf., H. huberi Carnevali & Morillo, H. lehmanniana Kraenzl. and H. seticauda Lindl. New synonyms are proposed and Habenaria marupaana Schltr. is included under the synonymy of H. amambayensis Schltr., H. platydactyla Kraenzl. under H. schwackei Barb. Rodr., H. mitomorpha Kraenzl. under H. subfiliformis Cogn., and H. pratensis (Salzm. ex Lindl.) Rchb. f. var. parviflora Cogn. under H. spathulifera Cogn.
TL;DR: O ovario e semi-infero, e os frutos sao bagas indeiscentes, originadas em sua maior parte a partir do desenvolvimento da porcao infera do ovario, possui a camada mecânica derivada of suas camadas internas.
Abstract: Miconia albicans fruit and seed coat ontogeny were described under light microscope The samples were fixed in formalin-aceto-alcohol (FAA), neutral-buffered formaldehyde solution (NBF) and formalin-ferrous sulphate (FFS) solutions, embedded in plastic resin, sectioned at 10 µm and stained with Toluidine Blue Specific dyes and/or reagents were used for the microchemical tests The ovary is semi-inferior and the indehiscent, fleshy globose berries are originated mainly from the development of the inferior portion of the ovary The immature pericarp is mainly parenchymatous with some sclereids, druse crystal and phenolic-like compounds idioblasts widespread in the mesocarp In the mature pericarp, the endocarp cells are often collapsed, the mesocarp is thick with cells more or less turgid, and the sclereids, the druses and the phenolic-like compound idioblasts are almost absent The ovules are anatropous, bitegmic and crassinucellate, and the zig-zag micropyle is formed by both the exostome and the endostome The mature seed is pyramidal-elongated in shape, exalbuminous and testal The raphal part occupies about 40% of the seed coat total length and had the mechanical layer derived from its inner layer The antiraphal side is non-multiplicative and the exotesta, mesotesta and endotesta are differentiated into a sclerotic layer, with the exotesta being the mechanical one The tegmen is absent
TL;DR: Os dados fenologicos encontrados rejeitam a hipotese do polinizador compartilhado e sustentam a Hipotese corrente de hibridacao na area estudada.
Abstract: This paper discusses the phenological strategies of Melocactus glaucescens Buining & Brederoo, M. paucispinus G. Heimen & R. Paul, M. ernestii Vaupel and M. ×albicephalus Buining & Brederoo, species from Chapada Diamantina, northeastern Brazil. Melocactus glaucescens, M. ernestii and M. ×albicephalus occur sympatrically in an area of "caatinga"/"cerrado" vegetation, and M. paucispinus in an area of "cerrado"/"campo rupestre". The superposition of flowering in these sympatric taxa was compared and analyzed. The phenology of M. paucispinus was correlated with both abiotic and biotic factors. Flowering of M. glaucescens and M. ×albicephalus were observed to be continuous (though with moderate peaks of activity), while fruiting was sub-annual. Melocactus ernestii exhibited an annual pattern of both flowering and fruiting; while in M. paucispinus the same patterns were sub-annual. These sympatric taxa showed 40% overlap of flowering periods, reaching to more than 50% in paired combinations of taxa, considering both the number of specimens flowering, as well as the quantity of resources being offered. Available information indicates that these taxa share pollinators, but phenological data rejects the hypothesis of shared pollinators and supports the hypothesis of hybridization in the study area. Rainfall was negatively correlated with flowering in M. paucispinus, but positively correlated with fruiting. Flowering of M. paucispinus in dry periods of the year avoids that erect flowers positioned in terminal cephalium, exposed in open areas of the vegetation, be damaged for the rains, while fruiting in rainy periods can be favorable to the dispersion and germination of this species.
TL;DR: The unique characteristics of the T. cacao products, the lipid-protein synthesis capacities of T. grandiflorum, T. subincanum and T. bicolor suggest various possibilities for new industrialized food, pharmaceutical and cosmetic products.
Abstract: Localization of the cotyledon reserves of Theobroma grandiflorum (Willd. ex Spreng.) K. Schum., T. subincanum Mart., T. bicolor Bonpl. and their analogies with T. cacao L.). Cotyledon mesophyll cell morphology and lipid and protein synthesis of T. grandiflorum, T. subincanum and T. bicolor were analyzed and compared with T. cacao. These species possess foliar cotyledons folded around the hypocotyl radicle axis, typical of Sterculiaceae. Fruit size, morphology and weight are very distinct amongst the four species and so are the respective seeds. The main axis of the T. grandiflorum and T. bicolor seeds measured about 30 mm, while T. subincanum and T. cacao seeds measured 17 mm and 26 mm respectively. The seed weights of T. grandiflorum, T. bicolor, T. subincanum and T. cacao were 11.6 g, 9.4 g, 2.1 g and 3.0 g, respectively. The cotyledon mesophylls of the four species contained mainly polysaccharides and lipid-protein reserve cells. Theobroma cacao, T. grandiflorum and T. subincanum were composed of greater than 50% lipids. For the four species, lipid globules gradually accumulated adjacent to the cell wall, and these globules measured from 1 to 3 µm. TEM showed low-density proteins inside the central vacuole of the young mesophyll cells of T. cacao. The protein reserves of the mature cells were densely scattered amongst the lipid bodies, and a few starch granules occurred together with the cotyledon mesophyll of the four species. Polyphenolic cells were found throughout the mesophyll cells or aligned with the respective vascular bundles. Immature cells demonstrated the capacity to synthesize all these reserves, but gradually the pre-determined cells produced mainly lipid-protein reserves. Besides the unique characteristics of the T. cacao products, the lipid-protein synthesis capacities of T. grandiflorum, T. subincanum and T. bicolor suggest various possibilities for new industrialized food, pharmaceutical and cosmetic products.