Ricochet pollination in Senna (Fabaceae) - petals deflect pollen jets and promote division of labour among flower structures.

Naturalists Fritz and Hermann Müller hypothesised that heteranthery often leads to a division of labour into 'feeding' and 'pollinating' stamens; the latter often being as long as the pistil so as to promote successful pollination on the bees' back. In many buzz-pollinated species of Senna, however, the so-called pollinating stamens are short and not level with the stigma, raising the question of how pollen is shed on the bees' back. Here we explore a mechanism called 'ricochet pollination'. We test whether division of labour is achieved through the interaction between short lower stamens and strongly concave 'deflector petals'. We studied the arrangement and morphology of the floral organs involved in the ricochet pollination, functioning of the flowers through artificial sonication and observed the interactions between bees and flowers in the field. The middle stamens are adapted to eject pollen downwards, which can be readily collected on the bee mid legs. Most of the pollen is ejected towards the deflector petal(s). Pollen from this set of stamens is more likely to contribute to pollination. The pollen grains seem to ricochet multiple times against the deflector petals to eventually reach the bee's back. The pollen ricochet mechanism promotes a division of labour by involving additional floral organs, such as petals, reinforcing the Müllers' division-of-labour hypothesis. However, alternative, non-multiexclusive hypotheses could be explored in genus Senna and other angiosperm species.

Karyotype diversity and genome size variation in Neotropical Maxillariinae orchids.

Orchidaceae is a widely distributed plant family with very diverse vegetative and floral morphology, and such variability is also reflected in their karyotypes. However, since only a low proportion of Orchidaceae has been analysed for chromosome data, greater diversity may await to be unveiled. Here we analyse both genome size (GS) and karyotype in two subtribes recently included in the broadened Maxillariinea to detect how much chromosome and GS variation there is in these groups and to evaluate which genome rearrangements are involved in the species evolution. To do so, the GS (14 species), the karyotype - based on chromosome number, heterochromatic banding and 5S and 45S rDNA localisation (18 species) - was characterised and analysed along with published data using phylogenetic approaches. The GS presented a high phylogenetic correlation and it was related to morphological groups in Bifrenaria (larger plants - higher GS). The two largest GS found among genera were caused by different mechanisms: polyploidy in Bifrenaria tyrianthina and accumulation of repetitive DNA in Scuticaria hadwenii. The chromosome number variability was caused mainly through descending dysploidy, and x=20 was estimated as the base chromosome number. Combining GS and karyotype data with molecular phylogeny, our data provide a more complete scenario of the karyotype evolution in Maxillariinae orchids, allowing us to suggest, besides dysploidy, that inversions and transposable elements as two mechanisms involved in the karyotype evolution. Such karyotype modifications could be associated with niche changes that occurred during species evolution.

Environmental variations drive polyploid evolution in neotropical Eugenia species (Myrtaceae).

Polyploidy is one of the most important mechanisms of speciation and diversification in plant evolution. Polyploidy results in genetic variation among individuals of the same species and even between populations, and may be responsible for differences in environmental tolerance between populations of the same species. This study determined chromosome numbers of Eugenia L. (Myrtaceae, x = 11) for 26 populations of 14 species by conventional cytogenetic techniques. Nine species (13 populations) were diploid (2n = 2x = 22), but diploid and/or polyploid cytotypes were found in the other five species (13 populations), with 2n = 33, 2n = 44, and 2n = 55. Data on chromosome number/ploidy level for other Eugenia species/populations were collected from the literature and included in this cytogeographic analysis. For each collection point (32 species and 62 populations), environmental variables were recorded using georeferencing techniques through the DIVA-GIS v.7.5 program. Environmental variables such as temperature, altitude, rainfall, solar radiation, soil type, and vegetation were analyzed with the R program, using Mann-Whitney and chi-square tests, principal component analysis, and graphic analyses, such as scatterplots, boxplots, and barplot. Polyploid and diploid populations had different spatial distribution patterns and were found in areas subjected to different environmental conditions. Polyploid individuals were collected from locations with more adverse environmental conditions, usually at higher elevations than the diploid individuals. Polyploidy allows species to occur at locations with varying environmental conditions. As diploidy and polyploidy occur under different environmental conditions, species with cytotypes exhibit wide environmental tolerance.

Capsule impairs efficient adherence of Streptococcus agalactiae to intestinal epithelium in tilapias Oreochromis sp.

Streptococcosis caused by Streptococcus agalactiae is one of the most important diseases in the tilapia aquaculture industry. The role of the capsule of Streptococcus agalactiae in adherence to fish surfaces has not been evaluated and the mechanism of capsular regulation during adhesion has not been described. The aim of this study was to evaluate the role of the capsule of S. agalactiae during adhesion to intestinal epithelium of tilapia (Oreochromis sp.) in an ex vivo infection model. We show that the capsule impairs the adhesion of bacteria to host intestinal epithelium. Wild type (WT) strain SaTiBe08-18 (S. agalactiae recovered from tilapia) had reduced adhesion (P < 0.0001) in comparison with its unencapsulated mutant of SaTiBe08-18 (Δcps). When WT was treated with sterile saline solution (pH 5) before infection of intestine explants, the adhesion was reached. The results suggest that the capsule impairs the adhesion of S. agalactiae to tilapia intestine and that the acidic milieu could regulate adherence of encapsulated strains. We found GlcNAc on the surface of adherent Δcps but not over the capsule in WT. This difference could be explained by the GlcNAc composition of Lancefield group B antigen and the peptidoglycan in GBS (Group B Streptococcus) and also may be related with better exposure of glycosylated adhesins in unencapsulated fish GBS. Understanding capsular regulation during adhesion of S. agalactiae may provide new leads to find a successful anti-adherence therapy to prevent streptococcosis in tilapia.

Changing epidemiology of group B streptococcal infections among adults in Iceland: 1975-2014.

We studied the bacterial characteristics and incidence of invasive infections caused by group B streptococci (GBS) in adults in Iceland in 1975-2014. A total of 145 isolates were characterized by serotyping, antimicrobial susceptibility, multilocus sequence typing and surface protein gene profiling. Disease incidence increased during the studied period (p <0.001), reaching 2.17 cases/100 000 person-years in 2013-14. Overall, serotype Ia was the most frequently found (23%), but serotypes Ib, II, III and V showed similar prevalence (14%-17%). Although there were notable changes in the proportion of most serotypes during the study period, only the decline of serotype III was statistically supported (p = 0.003) and was reflected in a decrease of clonal complexes CC17 and CC19 that included most serotype III isolates (p <0.04). On the other hand, the increase in frequency of CC1 was caused by two lineages expressing distinct serotypes: ST1/V/alp3 and ST196/IV/eps. Underlying the relative stability of serotype Ia were major changes in the lineages expressing this serotype, with an increase in the relative importance of CC23, including both ST23/Ia/eps and ST24/Ia/bca lineages, and a decrease in CC7. Nine cases of invasive GBS disease were caused by ST7, of possible zoonotic origin. All isolates were susceptible to penicillin. Rates of erythromycin and clindamycin resistance were 8.3% and 9.7%, respectively. An over-representation of resistance solely to clindamycin was associated with the unusual lsaC gene and serotype III ST19/rib lineage (p <0.001).

Teor e composição química do óleo essencial de erva-baleeira (Varronia curassavica Jaqc. ) em função dos horários de coleta / T: Content and chemical composition of the essential oil of 'erva-baleeira' (Varronia curassavica Jaqc. ) as a function of harvesting times

RESUMO A erva-baleeira (Varronia curassavica Jaqc.) é uma importante planta medicinal, com ocorrências em vários biomas brasileiros, dela é possível extrair óleo essencial utilizado na produção de fitoterápicos. O objetivo deste trabalho foi estudar o efeito do horário de coleta das folhas sobre o teor e os constituintes químicos do óleo essencial da V. curassavica. As folhas foram obtidas da coleção do germoplasma do Horto Medicinal do Instituto de Ciências Agrárias da Universidade Federal de Minas Gerais (ICA/UFMG). Os tratamentos constaram de cinco horários de coleta (6:00, 9:00, 12:00, 15:00 e 18:00 horas) e três repetições, utilizando o delineamento experimental inteiramente casualizado. O óleo essencial foi extraído pelo método de hidrodestilação, utilizando-se o sistema Clevenger e a constituição química determinada por cromatografia em fase gasosa acoplada à espectrometria de massas (CG/EM). O teor do óleo essencial não sofreu influencia do horário de coleta. Entretanto, o horário de coleta influenciou a composição química do óleo essencial de erva-baleeira. Os compostos majoritários em todos os horários de coleta foram β-cariofileno (22,6 a 27,4%), elixeno (14,9 a 17,2%) e γ-muuroleno (9,1 a 9,8%). Já o composto de menor abundância relativa, sabineno (1,1 %), apresentou ocorrência apenas as 6 h da manhã.

ABSTRACT The erva-baleeira (Varronia curassavica Jacq.) is an important medicinal plant which occurs in several Brazilian biomes, from which it is possible to extract essential oil used in the production of herbal medicines. The objective of this study was to observe the effect of the collection schedule for the leaves on the content and the chemical constituents of the essential oil of V. curassavica. The leaves were obtained from the germplasm collection of the Medicinal Garden of the Institute of Agricultural Sciences at the Federal University of Minas Gerais (ICA/UFMG). The treatments consisted of five collection schedules (6:00 and 9:00 AM, and 12:00, 3:00, and 6:00 PM) and three replications, using a completely randomized design. The essential oil was extracted by the hydrodistillation method, using the Clevenger system, and the chemical composition was determined by gas chromatography with mass spectrometry (GC/MS). The harvest time did not influence the content of the essential oil. However, the collection schedule did influence the chemical composition of the essential oil of erva-baleeira. The major compounds at all collection times were β-caryophyllene (22.6 to 27.4%), xylene (14.9 to 17.2%) and γ-muurolene (9.1 to 9.8%). The compound of lowest relative abundance, sabinene (1.1%), was found only at 6 AM.

Atividade antimicrobiana do óleo essencial de Lippia origanoides e Lippia rotundifolia frente a enterobactérias isoladas de aves / Antimicrobial activity of Lippia origanoides and Lippia rotundifolia oils against enterobacteria isolated from poultry

The aim of this study was to evaluate the antimicrobial activity of essential oils on enterobacteria Escherichia coli and Staphylococcus aureus isolated from poultry fecal samples in the cloaca from 49 laying hens. To analyze the antimicrobial sensibility an agar diffusion susceptibility test was performed and the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericida Concentration (MBC) of Lippia origanoides and Lippia rotundifolia essential oils was determined. The concentrations used were 160, 80 and 40 L/mL. The L. origanoides essential oil showed antimicrobial effect from 40 L/mL dose against both microorganisms, with larger efficiency in E. coli. The L.rotundifolia essential oil was more efficient at the concentration of 160L/mL. Its effect was observed in all microorganisms. These results suggest that L. origanoides oil is more effective than L. rotundifolia oil in inhibiting the growth of microorganism isolated from poultry, although it also has a satisfactory antimicrobial effect. Results indicate the potential use of these plant's essential oils in poultry feed as an alternative to conventional antimicrobial products.

Biologia floral e sistema reprodutivo da erva-baleeira (Varronia curassavica Jacq. ) / Flowering phenology and reproductive system of the Cordia (Varronia curassavica Jacq. )

RESUMOO conhecimento do sistema reprodutivo é fundamental para a conservação e manejo de uma espécie. O objetivo deste trabalho foi descrever a fenologia da floração, a antese, registrar os insetos visitantes no período de floração, determinar as características morfométricas das flores e o sistema reprodutivo da erva-baleeira, em um ambiente de Cerrado do Norte de Minas Gerais. Entre maio a dezembro de 2012 foi caracterizado o comportamento fenológico da floração. Na análise da fenologia floral foi determinado: o crescimento da inflorescência, o número de flores e frutos por inflorescências. Utilizou-se seis acessos que tiveram dez inflorescências marcadas em cada acesso, totalizando 60 inflorescências. A antese foi determinada utilizando quatro inflorescências em duas plantas. Os visitantes florais foram observados in loco e capturados em três dias consecutivos de coleta. As características morfométricas foram determinadas com paquímetro utilizando 20 flores, sendo cinco flores de quatro acessos. Para determinar o sistema reprodutivo utilizou-se a razão pólen:óvulo (P:O), utilizando 50 flores, sendo 10 flores de cinco acessos em pré-antese. Nas condições de Montes Claros, o crescimento das inflorescências de erva-baleeira ocorreu entre meados de agosto e início de outubro, totalizando 45 dias. O florescimento foi observado entre meados de setembro e final de outubro, enquanto a frutificação ocorreu de meados de outubro a início de dezembro, sendo que ambos ocorreram de forma irregular. A antese floral de erva-baleeira, neste estudo, ocorre entre 7:00 e 11:00 horas. Os insetos visitantes pertencem as ordens Coleoptera, Hemiptera, Diptera e Hymenoptera. As flores apresentaram o diâmetro de 2,13 ± 0,05 (mm), o comprimento de 3,29 ± 0,08 (mm), diâmetro do ovário de 0,70 ± 0,02 (mm), o comprimento do ovário de 2,48 ± 0,12 (mm), o diâmetro da antera de 0,67 ± 0,01(mm) e o comprimento da antera de 0,93 ±0,02 (mm), quatro óvulos e cinco anteras por flor. A razão P:O foi de 576,542, indicando que a espécie é alógama facultativa.

ABSTRACTThe knowledge of the reproductive system is essential for the conservation and management of the species. This study aimed on several procedures, as follows: to describe the phenology of flowering, the anthesis; to record the visiting insects during flowering and to determine the morphometric characteristics of the flowers and the reproductive system of the "erva-baleeira", in an environment of Northern Cerrado in the State of Minas Gerais. From May to December 2012, the flowering phenology of six access was characterized. In the analyzes of floral phenology it were determined the growth of the inflorescence and the number of flowers and fruits per inflorescence by using six access which had ten inflorescences marked in each access l, totalizing sixty inflorescences. The anthensis was assessed using four inflorescences in two plants. The flower`s visitors were observed live and captured in three consecutive days of sampling. The morphometric characteristics were determined with a caliper using 20 flowers, with five flowers from four access. In order to determine the reproductive system it was employed a ratiopollen: ovule (P: O) with 50 flowers and 10 of them belonging to five accesses in the pre-anthesis. Under the conditions of Montes Claros, the growth of inflorescences from Cordia occurred between mid-August and early October, totalizing 45 days. The flowering was observed between mid-September and late October, and the fruiting occurred from mid-October to early December. Both phases happened irregularly. The anthesis of the Cordia, in this study, occurred between 7:00 and 11:00 o`clock.. The visiting insects identified were from the orders of Coleoptera, Hemiptera, Diptera and Hymenoptera. The flowers exhibited a diameter of 2.13 ± 0.05 (mm), length of 3.29 ± 0.08 (mm), diameter of 0.70 ± 0.02 Ovarian (mm), the length of the ovary was 2.48 ± 0.12 (mm), the diameter of the anther 0.67 ± 0.01 (mm) and the length anther was 0.93 ± 0.02 (mm), with five anthers and four ovules per flower. The reason P: O was 576.542, indicating that the species is facultative allogamous.

Microsatellite in Aeschynomene falcata (Leguminosae): diversity, cross-amplification, and chromosome localization.

Aeschynomene falcata is an important forage species; however, because of low seed production, it is underutilized as forage species. Aeschynomene is a polyphyletic genus with a challenging taxonomic position. Two subgenera have been proposed, and it is suggested that Aeschynomene can be split in 2 genera. Thus, new markers, such as microsatellite sequences, are desirable for improving breeding programs for A. falcata. Based on transferability and in situ localization, these microsatellite sequences can be applied as chromosome markers in the genus Aeschynomene and closely related genera. Here, we report the first microsatellite library developed for this genus; 11 microsatellites were characterized, with observed and expected heterozygosities ranging from 0.0000 to 0.7143 and from 0.1287 to 0.8360, respectively. Polymorphic information content varied from 0.1167 to 0.7786. The departure from Hardy-Weinberg equilibrium may have resulted from frequent autogamy, which is characteristic of A. falcata. Of the 11 microsatellites, 9 loci were cross-amplified in A. brevipes and A. paniculata and 7 in Dalbergia nigra and Machaerium vestitum. Five of these 7 cross-amplified microsatellites were applied as probes during the in situ hybridization assay and 2 showed clear signals on A. falcata chromosomes, ensuring their viability as chromosome markers.

Characterization of diversity and genetic structure in natural populations of Stryphnodendron adstringens (Mart. ) Coville by means of allozyme markers

O S. adstringens, árvore típica do Cerrado, tem sido explorada visando suas propriedades medicinais e tanantes. Em razão do ainda incipiente conhecimento genético da espécie, este trabalho teve como objetivo caracterizar a diversidade e a estrutura genética de S. adstringens por meio de marcadores aloenzimáticos. Foram coletadas sementes em cinco mesorregiões brasileiras, sendo amostrados 627 indivíduos divididos em 16 populações localizadas nos Estados de Minas Gerais e Goiás. Foram testados 14 sistemas isoenzimáticos; destes, sete foram polimórficos com o total de 10 locos e 28 alelos. O valor de diversidade genética média (H) foi 0,226, a proporção média de locos polimórficos (P) foi 68,75, o número médio de alelos por loco polimórfico (AP) foi 2,65 e o número efetivo de alelos (Ae) foi igual a 1,29. Resultados do índice de fixação total (F= 0,003), do índice de fixação dentro de populações (f = -0,114) e, da medida de diferenciação genética (θ =0,105) foram não significativos, indicando a inexistência de estruturação genética. Na análise de agrupamento (UPGMA) foram observados dois grupos principais, o primeiro formado pela população do Parque Estadual (PE) do Rio Preto (MG), e outro, formado pelas demais populações. Se excluída a população do PE do Rio Preto das análises, G ST é drasticamente reduzido de 0,077 para 0,026. Assim, aproximadamente 2/3 do valor total de G ST verificado em S. adstringens foi devido à variação entre a população do PE do Rio Preto e as demais populações. De modo geral, os valores H e P observados em S. adstringens são compatíveis aos constatados em árvores tropicais comumente distribuídas. Por outro lado, excluindo a população do PE do Rio Preto, o valor da medida de diferenciação genética G ST foi menor que o verificado em árvores tropicais nativas e pinheiros de zonas temperadas. A semelhança entre populações avaliadas indica que o fluxo gênico ainda é alto o suficiente para prevenir a diferenciação genética, pelo menos em nível local.

The S. adstringens, a typical Cerrado (Brazilian savannah) tree, is used because of its medicinal and tanning properties. Because of the still incipient genetic knowledge of the species, the objective of this work was to characterize the diversity and genetic structure of S. adstringens by using allozyme markers. Seeds were collected in five Brazilian mesoregions, in which 627 individuals in 16 populations in the states of Minas Gerais and Goiás were sampled. Fourteen isoenzyme systems were assessed, out of which seven were polymorphic with a total of 10 loci and 28 alleles. Average genetic diversity (H) was 0.226, average proportion of polymorphic loci (P) was 68.75, average number of alleles per polymorphic locus (AP) was 2.65 and effective number of alleles (Ae) was equal to 1.29. The results of total fixation index (F= 0.003), within population fixation index (f =-0.114) and genetic differentiation measure (θ =0.105) were not significant, which shows the inexistence of genetic structure. Two principal groups were found in the cluster analysis (UPGMA), where the first one was formed by the population of State Park (PE) of Rio Preto (MG) and the other, by the other populations. If the population of PE of Rio Preto is excluded from the analysis, G ST is drastically reduced from 0.077 to 0.026. Thus, approximately 2/3 of the total value of G ST found in S. adstringens was due to the variation among the population of PE of Rio Preto and the other populations. Overall, the values of H and P found in S. adstringens are compatible with the ones found in typically distributed tropical trees. On the other hand, by excluding the population of PE of Rio Preto, the value of the G ST genetic differentiation measure was smaller than the one found in native tropical trees from temperate zones. The similarity between the assessed populations shows that the gene flow is still high enough to avoid genetic differentiation, at the local level, at least.

Reguladores vegetais e substratos no enraizamento de estacas de erva-baleeira (Varronia curassavica Jacq. ) / Growth regulators and substrates on rooting of Varronia curassavica Jacq

A erva-baleeira, espécie medicinal anti-inflamatória, pode ser propagada por sementes, no entanto, o desenvolvimento de métodos eficientes para a propagação vegetativa possibilitará a uniformidade nas populações e a clonagem de plantas de interesse quanto aos aspectos agronômico e de composição química. O presente trabalho objetivou avaliar os efeitos do ácido naftaleno acético (NAA) e do ácido indolbutírico (IBA) e de diferentes substratos no enraizamento de estacas semi-lenhosas de erva-baleeira. Os experimentos foram conduzidos em casa de vegetação em Montes Claros em delineamento inteiramente casualizados. Para o experimento teste da influência das auxinas, as estacas foram submetidas a tratamentos com NAA e IBA nas concentrações de 0, 500, 1000, 2000, 3000 e 4000 mg L-1, e para o experimento dos substratos, cinco substratos foram avaliados (vermiculita expandida + casca de arroz parcialmente carbonizada (proporção de 1:1); vermiculita expandida; substrato orgânico comercial para hortaliça (Tropstrato HT ®); areia; solo + compostagem (proporção de 1:1)). Após 90 dias, para ambos os experimentos, foram avaliadas porcentagem de estacas enraizadas, de estacas mortas, de estacas vivas com calos, de estacas mortas com calos, número de raízes formadas por estaca e comprimento das três maiores raízes (cm). O regulador vegetal ideal para o enraizamento da espécie é o IBA, na concentração de 2.000 mg L-1, sendo que o NAA não é recomendado para a indução radicial em estacas erva-baleeira. O substrato vermiculita com casca de arroz carbonizada na proporção de 1:1 proporcionou maior porcentagem de enraizamento nas estacas da erva-baleira que o substrato solo + compostagem (1:1), os demais substratos não diferenciaram entre si.

The Varronia curassavica Jacq., black sage, is an anti-inflammatory medicinal species that can be propagated by seed; however, the development of efficient methods for vegetative propagation will enable uniformity in the populations and cloning of plants of interest regarding the agronomic aspects and chemical composition. The aim of this study was to assess the effects of the naphthalene acetic acid (NAA) and indole butyric acid (IBA) and different substrates on the rooting of semi-hardwood cuttings of black sage. The experiments were conducted in a greenhouse at Montes Claros, in the State of Minas Gerais, Brazil, as a randomized complete design. For the experiment to test the influence of auxin, the cuttings were subjected to treatments with NAA and IBA at the concentrations of 0, 500, 1000, 2000, 3000 and 4000 mg L-1, and for the experiment with substrates, five substrates were evaluated (expanded vermiculite + carbonized rice husk (1:1); expanded vermiculite; commercial organic substrate for vegetable (Tropstrato ® HT); sand; soil + compost (1:1)). After 90 days, in both experiments, we evaluated the rooting percentage of cuttings, dead cuttings, live cuttings with callus, dead cuttings with callus, number of roots per cutting and length of the three longest roots (cm). The best plant growth regulator for the rooting of the species is the IBA at a concentration of 2.000 mg L-1, and the NAA is not recommended for the induction of roots in cuttings of black sage. Vermiculite with carbonized rice husk in the ratio of 1:1 showed greater percentage of rooting in cuttings of black sage than soil + composting (1:1); other substrates did not differ among themselves.

Composição química e atividade in vitro de três óleos essenciais sobre Colletotrichum gloeosporioides do maracujazeiro / Chemical composition and in vitro activity of three essential oils on Colletotrichum gloeosporioides from passion fruit

Objetivou-se avaliar a ação de diferentes concentrações de óleos essenciais de três plantas medicinais sobre o crescimento micelial, a produção e a germinação de conídios de Colletotrichum gloeosporioides (Penz.). Utilizou-se os óleos essenciais de Lippia sidoides Cham., Cymbopogon citratus (DC) Stapf.) e Ocimum gratissimum L. em cinco concentrações (0 µL mL-1, 1 µL mL-1, 3 µL mL-1, 5 µL mL-1 e 7 µL mL-1) com 4 repetições no delineamento inteiramente casualizado, em esquema fatorial 5x3. Os óleos foram analisados por cromatografia gasosa acoplada com espectrometria de massas. Para todas as características verificou-se efeito significativo da interação "Óleo" versus "Concentração". O óleo essencial de C. citratus proporcionou a maior inibição do crescimento micelial em todas as concentrações testadas. Os outros óleos não se diferenciaram, exceto a partir da concentração de 5 µL mL-1, onde o óleo de L. sidoides foi superior ao óleo de O. gratissimum. Na produção e germinação de conídios, o óleo de C. citratus, foi superior aos óleos de L. sidoides e de O. gratissimum nas concentrações de 1 µL mL-1 e 3 µL mL-1, inibindo completamente a produção e germinação a partir da concentração de 3 µL mL-1. As concentrações influenciam em todas as variáveis, ajustando-se à equação do modelo linear. Observa-se o decréscimo nessas, à medida em que se aumentam as concentrações dos óleos testados. Os óleos essenciais testados possuem efeito fungitóxico e fungistático.

The objective of this study was to evaluate the action of different concentrations of essential oils of three medicinal plants on the mycelial growth, production and conidial germination of Colletotrichum gloeosporioides (Penz.). We used a completely randomized design, in a 5x3 factorial design, being five concentrations (0 µL mL-1, 1 µL mL-1, 3 µL mL-1, 5 µL mL-1 e 7 µL mL-1) x three oils from Lippia sidoides Cham., Cymbopogon citratus (DC) Stapf. and Ocimum gratissimum L., with four replications. The oils were analyzed by gas chromatography with mass spectrometry. There was a significant interaction of concentration versus species on all analyzed traits. The essential oil from C. citratus yielded the highest mycelial growth inhibition at all concentrations. The other oils were not differentiated, except at the concentration of 5µL mL-1, in which the oil of L. sidoides was more efficient that the oil of O. gratissimum. In conidial production and germination, the oil of C. citratus was superior to the oil of L. sidoides and O. gratissimum at the concentrations of 1 µL mL-1 and 3 µL mL-1, as it completely inhibited the production and germination of conidia at the concentrations of 3 µL mL-1 and above. The concentrations influenced all the variables, adjusting themselves to the linear model equation. We observed a decrease in the variables, as the concentrations of the oils tested are increased. The essential oils used have antifungal and fungicidal effect.

Avaliação da atividade antibacteriana do óleo essencial de Lippia origanoides frente à Staphylococcus sp. isolados de alimentos de origem animal / Assessment of the antibacterial activity of the essential oil of Lippia origanoides in relation to Staphylococcus sp. isolated from food of animal origin

Objetivou-se no trabalho avaliar a ação antibacteriana do óleo essencial de Lippia origanoides frente à isolados de Staphylococcus sp. de alimentos de origem animal. Para tanto, realizou-se análise química da composição do óleo, teste de sensibilidade das bactérias frente a dez antibióticos de uso terapêutico e ao óleo essencial de Lippia origanoides, além da determinação da concentração inibitória mínima (CIM) e da concentração bactericida mínima (CBM). A análise cromatográfica do óleo apresentou o timol como composto majoritário (48,70%), além de pequena quantidade de carvacrol (1,14%). No teste de sensibilidade frente aos antibióticos, 75% dos isolados apresentaram resistência a, no mínimo, três antibióticos. Em relação ao óleo essencial, os isolados de Staphylococcus sp oriundos de leite bovino mostraram-se mais resistentes e os isolados de carne ovina apresentaram-se mais sensíveis. A CIM foi maior para os Staphylococcus sp. isolados de leite bovino e leite ovino (60µL/mL). Enquanto que para os isolados de carcaça de ovinos e queijo, a CIM foi de 15µL/mL e 30µL/mL respectivamente. A CBM, consequentemente, foi maior para os isolados de leite bovino e leite ovino, sendo de 240µL/mL e 120µL/mL respectivamente. O óleo essencial de Lippia origanoides apresenta atividade antimicrobiana sobre Staphylococcus sp. isolados de alimentos.

The aim of this study was to evaluate the antibacterial activity of the essential oil of Lippia origanoides in relation to Staphylococcus sp. isolated from food of animal origin. For this purpose, we performed the chemical analysis to determine the oil composition, evaluated the bacteria sensibility to ten antibiotics of therapeutic use and determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The chromatographic analysis showed that tymol was the main compound (48.70%) and that carvacrol was present in a small amount (1.14%). In the test of antibiotic susceptibility, 75% of the microorganism isolates were resistant to at least three of the ten antibiotics tested. The Staphylococcus sp isolated from bovine milk was more resistant to the essential oil of Lippia origanoides, and the microorganism isolated from sheep meat was more susceptible to this oil. The Staphylococcus sp. isolated from bovine or sheep milk showed a MIC of 60µL/mL and for those isolated from sheep carcass and cheese the MIC was 15µL/mL and 30µL/mL, respectively. Consequently, the MBC was higher for isolates from cow's (240µL/mL) and sheep's milk (120µL/mL) when compared with other food sources. These results suggest that the essential oil of Lippia origanoides has antimicrobial activity against staphylococcus sp. isolated from food.

Karyotype evolution and phylogenetic analyses in the genus Cardiospermum L. (Paullinieae, Sapindaceae).

Cardiospermum L. belongs to the Paullinieae tribe (Sapindaceae) and comprises 16 species. Of these, 12 species are present in South America and all occur in Brazil. Cardiospermum shows the most variable chromosome number of the tribe. Phylogenetic relationships within the genus Cardiospermum, especially with other species of the tribe, are poorly understood. This research focuses on characterisation of the karyotypic features of Cardiospermum using conventional cytogenetic methods, CMA/DAPI chromosome banding and fluorescence in situ hybridisation (FISH). To elucidate the phylogeny of the genus, the nuclear markers ITS1 and ITS2 were sequenced and analysed using maximum parsimony and Bayesian inference. Cardiospermum shows important diversity in basic numbers, with x = 7, 9, 10, 11 and 12. All species studied have metacentric and submetacentric chromosomes, some species have subtelocentric chromosomes, while telocentric chromosomes are absent. The interphase nuclei differentiate the Cardiospermum species into two groups. The CMA(3) /DAPI chromosome banding revealed the presence of an AT-rich terminal region in C. corindum, C. grandiflorum and C. urvilleoides, whereas GC-rich regions were found in C. grandiflorum, C. halicacabum var. halicacabum, C. halicacabum var. microcarpum, C. heringeri and C. integerrimum. FISH revealed syntenic and non-syntenic distribution of the 18-5.8-26S and 5S rDNA. The syntenic distribution always occurred in the short arms of the same chromosome in all of the species. The phylogenetic relationships reveal, in part, the taxonomic arrangement of the genus Cardiospermum.

Distribution of pilus islands in Streptococcus agalactiae that cause human infections: insights into evolution and implication for vaccine development.

At least one pilus island, PI-1 (70%), PI-2a (79%), or PI-2b (21%), was found among 898 Streptococcus agalactiae (group B streptococcus [GBS]) isolates recovered from humans, supporting the use of pilus proteins in vaccines. The stability and dominance of PI-1 and PI-2a in multiple serotypes and founder multilocus sequence types disseminated worldwide suggest it could be the PI combination present in ancestral GBS human pathogens.

Medicinal plant extracts on the control of Diabrotica speciosa (Coleoptera: Chrysomelidae) / Extratos de plantas medicinais no controle de Diabrotica speciosa (Coleoptera: Chrysomelidae)

The aim of this study was to evaluate the insecticidal effect of aqueous, alcoholic, and oil extracts from leaves of eight medicinal plants against Diabrotica speciosa prepared at five concentrations. The extracts that used commercial soybean oil as solvent showed the highest D. speciosa mortality due to the solvent itself, regardless of the used plants and their concentrations. Thus, commercial soybean oil was discarded as solvent since at these volumes it would cause serious phytotoxicity problems. After 24 hours of exposure of the pest to the extracts, the highest D. speciosa mortality values were observed for Copaifera langsdorfii and Chenopodium ambrosioides extracts, both in 5% alcohol, and Artemisia verlotorum, in 10% water. However, in the last mortality assessment (48 h), C. langsdorfii extract in 5% alcohol showed higher mortality of this pest, followed by C. ambrosioides extract in 5% alcohol, compared to the remaining plants.

O objetivo deste trabalho foi avaliar o efeito inseticida de extratos aquosos, alcoólicos e oleosos de folhas de oito plantas medicinais contra Diabrotica speciosa preparadas em cinco concentrações. Os extratos que utilizaram óleo de soja comercial como solvente apresentaram as maiores mortalidades de D. speciosa em função do próprio óleo, independentemente das plantas utilizadas em suas concentrações. Sendo assim, o óleo de soja comercial foi descartado como solvente, pois nestes volumes acarretaria sérios problemas de fitotoxidade. Após 24 horas de exposição da praga aos extratos, os maiores valores de mortalidade de D. speciosa foram observados nos extratos de Copaifera Langsdorfii e de Chenopodium ambrosioides, ambos em álcool 5%, e de Artemisia verlotorum, em água 10%. Entretanto, na última avaliação de mortalidade (48 h), o extrato de C. langsdorfii em álcool a 5% apresentou maior mortalidade dessa praga, seguida pelo extrato alcoólico a 5% de C. ambrosioides comparada às demais plantas.

Organic fertilization affecting pests and production of Lippia sidoides Cham. (Verbenacea) / Adubação orgânica afetando a ocorrência de pragas e a produção de Óleo essencial em Lippia sidoides Cham. (Verbenacea)

The objective of this paper was to study the effect of four levels of organic fertilization (0, 3, 6 and 9 kg m-2) to produce the essential oil of Lippia sidoides Cham. (Verbenacea) and its pests. A higher number of red mite Tetranychus sp. (Acari: Tetranychiidae) was observed on the abaxial face of the median and basal leaves of L. sidoides plants with eight weeks of age cultivated with 6 kg m-2 of organic fertilization. On the other hand, the smallest number of this mite was noted in control (0 kg m-2). L. sidoides cultivated with 6 kg m-2 of organic fertilization produced a greater quantity of essential oil. The highest number of mealy bug Phenacoccus sp. (Hemiptera: Pseudococcidae) was observed on the apical leaves (both leaf surfaces) of L. sidoides plants with nine and ten weeks of age cultivated with 3 kg m-2 of organic fertilization. No significant effect of the organic fertilization on Aphis gossypii Glover (Hemiptera: Aphididae) was detected. However, a greater number of this aphid and of its predator Scymnus sp. (Coleoptera: Coccinelidae) was observed on the abaxial face of the bottom leaves of L. sidoides plants with eight weeks of age. The dose of organic fertilization recommended for the production of essential oil of L. Sidoides is 6 kg m-2, however, one must pay attention to the fact this dosage favors the attack by Tetranychus sp.. And, when needed, pulverization must always be directed to the lower surface of the leaf.

O objetivo deste trabalho foi avaliar o efeito de quatro níveis de adubação orgânica (0, 3, 6, e 9 kg m-2) na produção de óleo essencial de Lippia sidoides Cham. (Verbenacea) e de suas pragas. Observou-se maior número de ácaro vermelho Tetranychus sp. (Acari: Tetranychiidae) na face inferior das folhas dos terços medianos e basais das plantas de L. sidoides com oito semanas de idade cultivadas com 6 kg m-2 de adubo orgânico. Por outro lado, a menor quantidade deste ácaro foi notada na testemunha (0 kg m-2). L. sidoides cultivada com 6 kg m-2 de adubo orgânico produziu maior quantidade de óleo essencial. Observou-se maior número de cochonilhas Phenacoccus sp. (Hemiptera: Pseudococcidae) nas folhas apicais, sem distinção de face foliar, das plantas de L. sidoides com nove e 10 semanas de idade cultivadas com 3 kg m-2 de adubo orgânico. Não se detectou efeito significativo de adubo orgânico sobre Aphis gossypii Glover (Hemiptera: Aphididae). Contudo, observou-se maior número desse pulgão bem como de seu predador Scymnus sp. (Coleoptera: Coccinelidae) nas faces abaxiais das folhas basais das plantas de L. sidoides com oito semanas de idade. A dose de adubo orgânico recomendada para produção de óleo essencial de L. sidoides é de 6 kg m-2. Contudo, essa dosagem favorece o ataque de Tetranychus sp. e, quando necessário, deve-se dirigir a pulverização sempre para a face inferior da folha, local preferencial de ataque dos artrópodes.

Estudo do sistema de reprodução da fava-d'anta (Dimorphandra mollis Benth. ) / Determination of the reproductive system of fava-d'anta (Dimorphandra mollis Benth. )

Entre as plantas nativas de uso medicinal do Cerrado brasileiro encontra-se a fava-d'anta (Dimorphandra mollis Benth) com alto potencial econômico por possuir inúmeras potencialidades medicinais e fitoquímicas. A indústria extrai dos frutos os princípios ativos rutina, quercetina, e ramnose, dentre outros, usados na fabricação de medicamentos e cosméticos, principalmente no exterior. O conhecimento do sistema reprodutivo da espécie é fundamental para sua conservação e manejo. O presente trabalho objetivou determinar as características morfométricas das flores e caracterizar o sistema reprodutivo da D. mollis em área de Cerrado inalterada antropomorficamente, no município de Olhos D'água - MG. Para as características morfométricas, diâmetro da flor, comprimento da flor, do ovário, e da antera, foram utilizadas cinco flores em pré-antese. Para a determinação do sistema reprodutivo utilizou-se a razão pólen:óvulo (P:O), em 40 flores. As flores da D. mollis apresentaram comprimento da flor de 3,00 mm, diâmetro da flor de 2,00 mm, comprimento do óvulo de 2,60 mm, comprimento da antera de 1,57 mm, e o número de óvulos e de anteras foram 20 e 5,8, respectivamente. A razão P:O foi 765,030, sendo que esse índice não é afetado pelas características morfométricas. O sistema reprodutivo da D. mollis foi classificado como alógama facultativa.

Among the native medicinal plants of the Brazilian Cerrado, we can find the fava-d'anta (Dimorphandra mollis Benth) with a high economic potencial due to its numerous possivbilities for medicinal and phytochemical use. The industry extracts form the fruits the active ingredients rutin, quercetin and rhamnose, among others, used to manufacture medications and cosmetic products, especially abroad. Knowing the reproductive system of the species is important for its conservation and management. This study aimed to determine the morphometric characteristics of flowers and characterize the reproductive system of D. mollis in a Cerrado area that was anthropomorphically unchanged, in the municipality of Olhos D'água - MG. For the morphometric characteristics, flower diameter, length of the flower, of the ovary and the anther, five pre-anthesis flowers were used. To determine the reproductive system, the pollen:ovule (P:O) ratio was used in 40 flowers. The D. mollis flowers presented a flower length of 3.00 mm, flower diameter of 2.00 mm, ovule length of 2.60 mm, anthers length of 1.57 mm, and the number of anthers and ovules were 20 and 5.8, respectively. The P:O ratio was 765,030, and this index is not affected by the morphometric characteristics. The reproductive system of D. mollis was classified as facultative allogamous.

Karyotype characterization of two populations of Vernonia geminata (Asteraceae, Vernonieae) using banding and FISH techniques.

In order to extend our knowledge concerning karyotypes of the genus Vernonia, we applied various techniques of chromosome banding, including AgNOR and triple staining with the fluorochromes CMA/DA/DAPI (CDD), and of fluorescent in situ hybridization (FISH) for the 45S rDNA probe to specimens of two populations of Vernonia geminata collected from an open-pasture area, in southern Brazil. B chromosomes were observed in one of the populations. Both populations of V. geminata presented a pair of CMA(3)(+) terminal bands and one pair of chromosomes with terminal AgNOR banding. The FISH evidenced, in one population, two pairs of small sites of 45S rDNA; these being two small terminal sites and two centromeric sites. In the other population, there was only one pair of small terminal sites and two sites in two B chromosomes, one in each chromosome. There was coincidence of localization between CMA(+) and NOR bands with one of the small terminal sites of 45S rDNA of one chromosome of the normal complement, but not in B chromosomes.