Diversity of vegetable landraces in the Pampa biome of Brazil and Uruguay: utilization and conservation strategies.

The historical meeting between originally American people, European colonizers, and slaved peoples from Africa in the biome Pampa in South Brazil and Uruguay involved a cultural syncretism and a great genetic diversity of landraces of cultivated species. Genetic richness evolved by selection and cultural processes in response to different environments, cultural backgrounds, and needs. This review summarized the knowledge on vegetable and maize landraces in South Brazilian and Uruguayan Pampa biome, to design a strategy towards the rediscovery, conservation, and sustainable use. Landraces diversity maintained in situ and ex situ is described, specific case studies are presented, and the main problems and tools towards landraces re-valorization are discussed. We show that traditional family farming systems maintain diverse vegetable species, mainly squashes (Cucurbita spp.), sweet potato (Ipomoea batatas), beans (Phaseolus spp.), onion (Allium cepa), peppers (Capsicum spp.), tomato (Solanum lycopersicum), next to leafy vegetables and maize, among others. We propose the priority of systematic surveys as a basis for monitoring genetic erosion, increasing complementariness between in situ and ex situ conservation, and implementing sustainable conservation and utilization. The case studies highlight genetic diversity within each cultivated species, with different crop physiological responses; disease resistances, different quality traits and associated uses, from animal feeding in maize to a range of culinary uses linked to traditional culture in maize and vegetable species, and ornamental uses of specific Capsicum and Cucurbita. Some landraces were the basis for breeding, where improved cultivars allowed the competitiveness of landrace germplasm in the markets. Renewed industrialized products allowed the competitive and sustainable use of Capsicum landraces in Brazilian farmers communities. Strategies towards in situ conservation improvements and valorization are discussed; emphasizing the role played by agroecology, community seed banks and custodian farmers, participatory plant breeding, promotion of landraces specialties among consumers, and the need of research and capacity building, among others. Farmers' participation in the decisions is a key factor, along with the academia and the public sector. Landraces and associated knowledge are treasures to be used to benefit from farmers to consumers, directing the course of agriculture towards sustainable directions.

Using multilayer perceptron and similarity-weighted machine learning algorithms to reconstruct the past: A case study of the agricultural expansion on grasslands in the Uruguayan savannas.

Changes in land use and land cover (LULC) have significant implications for biodiversity, ecosystem functioning, and deforestation. Modeling LULC changes is crucial to understanding anthropogenic impacts on environmental conservation and ecosystem services. Although previous studies have focused on predicting future changes, there is a growing need to determine past scenarios using new assessment tools. This study proposes a methodology for LULC past scenario generation based on transition analysis. Aiming to hindcast LULC scenario in 1970 based on the transition analysis of the past 35 years (from 1985 to 2020), two machine learning algorithms, multilayer perceptron (MLP) and similarity weighted (SimWeight), were employed to determine the driver variables most related to conversions in LULC and to simulate the past. The study focused on the Aristida spp. grasslands in the Uruguayan savannas, where native grasslands have been extensively converted to agricultural areas. Land use and land cover data from the MapBiomas project were integrated with spatial variables such as altimetry, slope, pedology, and linear distances from rivers, roads, urban areas, agriculture, forest, forestry, and native grasslands. The accuracy of the predicted maps was assessed through stratified random sampling of reference images from the Multispectral Scanner (MSS) sensor. The results demonstrate a reduction of approximately 659 934 ha of native grasslands in the study area between 1985 and 2020, directly proportional to the increase in cultivable areas. The MLP algorithm exhibited moderate performance, with notable errors in classifying agriculture and grassland areas. In contrast, the SimWeight algorithm displayed better accuracy, particularly in distinguishing grassland and agriculture classes. The modeled map using SimWeight accurately represented the transitions between grassland and agriculture with a high level of agreement. By modeling the 1970s scenario using the SimWeight model, it was estimated that the Aristida spp. grasslands experienced a substantial reduction in grassland coverage, ranging from 9982.31 to 10 022.32 km2 between 1970 and 2020. This represents a range of 60.8%-61.07% of the total grassland area in 1970. These findings provide valuable insights into the driving factors behind land use change in the Aristida spp. grasslands and offer useful information for land management, conservation, and sustainable development in the region. The study's main contribution lies in the hindcasting of past LULC scenarios, utilizing a tool used primarily for forecasting future scenarios. Integr Environ Assess Manag 2023;00:1-16. © 2023 SETAC.

Emergence of Mansonella sp. in free-ranging primates in southern Brazil.

Mansonellosis is a neglected and emerging tropical disease. Among all zoonotic filarial diseases, it is probably the most prevalent and least studied, with approximately 114 million people infected. The parasites of Mansonella spp. are among the most common blood parasitemias and are widely found in Africa and Latin America. Through molecular analysis of blood samples from free-ranging primates Sapajus nigritus (n 33) and Alouatta guariba clamitans (n 5) in the southern states of Brazil (Santa Catarina and Rio Grande do Sul), we identified samples positive for Mansonella perstans in two specimens of A. guariba clamitans. A fragment of 578 bp from the ITS intergenic region (5.8S-ITS2-28S) was targeted for an initial PCR screening. Subsequently, positive samples were subjected to other PCR assays targeting a fragment of the 12S and the 18S genes. This is the first record of molecular detection of the agent in this host in the Pampa Biome. With a wide distribution across Brazil and Argentina, these primates may represent a potential wild reservoir for the zoonotic agent of mansonellosis. Entomological and transmission studies are essential to avoid the urbanization of mansonellosis and to understand the cycles of agents in different environmental scenarios.

High Atmospheric CO2 Concentration Mitigates Drought Effects on Acanthostyles buniifolius an Important Grassland Weed in South America.

The differential growth and yield response of plant species to rising carbon dioxide concentrations and climatic change may alter species diversity within biomes. The Pampa Biome in South America is an important grassland biome of agronomic and environmental importance. Acanthostyles buniifolius (Chirca) is one of the most important weeds in natural pasture areas widely distributed in southern South America and can adversely affect livestock production. The current study was designed to identify possible responses of Chirca to CO2 concentration ([CO2]) and drought that would indicate higher adaptation and potential proliferation within the Pampa Biome. Chirca plants were cultivated at two CO2 concentrations (400 (a[CO2]) and 700 (e[CO2]) µmol mol-1) and two water conditions (under water restriction-15% of the pot capacity; and plants without water restriction-pot capacity). Besides growth parameters, we also determined water potential (ѱw), relative water contents (RWC), proline, glycine betaine, total soluble sugars, hydrogen peroxide, lipid peroxidation, superoxide dismutase (SOD), ascorbate peroxidase (APX) activity, chlorophyll A and B, carotenoids and root dry mass (RDM). Plants exposed to e[CO2] are more efficient in water use and have a greater increase in root dry mass, enabling greater adaptation to climate-induced droughts. Among the biochemical changes observed in the plants under drought stress, the accumulation of proline, glycine betaine, and total soluble sugars were the most evident mechanisms allowing plants to tolerate drought stress by osmotic adjustment.

Molecular Detection of Trypanosoma kaiowa in Tabanus triangulum (Diptera: Tabanidae) from the Coastal Plain of Rio Grande do Sul, Southern Brazil.

PURPOSE: The species of the genus Trypanosoma are carried and transmitted by horseflies parasitizing a high diversity of vertebrates. In the Coastal Plain of Rio Grande do Sul, southern Brazil, Tabanus triangulum is the most abundant species and, similarly to the other species of horseflies, there is little knowledge about its vector competence. Therefore, this study aimed to screen the field-collected T. triangulum for the presence of Trypanosoma, to estimate infectivity. METHODS: Horseflies were sampled by the Malaise trap in the forest fragments at the coastal plain and DNA was extracted from whole body flies. The Polymerase Chain Reaction was performed. RESULTS: Horseflies presented amplification of 18S ribosomal gene-specific of Trypanosoma species. DNA sequencing and phylogenetic analysis positioned the strains in the Kaiowa clade with Trypanosoma kaiowa, associated with the crocodilian clade of Trypanosoma. CONCLUSION: This study represents the first report of the presence of the Tr. kaiowa in T. triangulum and the expansion of the parasite's range further south in South America.

Serosurvey of antibodies against zoonotic pathogens in free-ranging wild canids (Cerdocyon thous and Lycalopex gymnocercus) from Southern Brazil.

The expansion of urbanization on natural areas is increasing contact between human populations with wild animals. Wild carnivores can act as sentinel hosts or environmental health indicators. Thus, the aim of this work was to investigate the exposure of two major species of wild canids from Southern Brazil to selected pathogens. For that, we live-trapped free-ranging Cerdocyon thous and Lycalopex gymnocercus in five localities and determined the frequency of animals with antibodies against Toxoplasma gondii, Trypanosoma cruzi, Leishmania infantum, Neospora caninum, and Leptospira spp. Among the canids sampled, 23% (12/52) (95%CI: 13-36%) had antibodies against T. gondii, with titers ranging from 64 to 512. For T. cruzi, 28% (15/52) (95%CI: 18-42%) of sampled canids were seropositive, with titers ranging from 8 to 64. Concerning the protozoan pathogen N. caninum, a total of 5% (3/52) (95%CI: 2-15%) of wild canids had antibodies against it. None of the sampled canids showed the presence of antibodies against L. infantum. On the other hand, 44% (23/52) (95%CI: 31-57%) of the wild canids showed antibodies against Leptospira spp. The set of results presented here, show that free-ranging neotropical wild canids are exposed and have antibodies against to T. gondii, T. cruzi, Leptospira spp., and to a lesser degree to N. caninum. We found no evidence of L. infantum circulation among the studied populations. These results highlight some of the major pathogens which may represent risks for populations of these wild canids. DATA AVAILABILITY STATEMENT: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Chemical characterization and antimicrobial activity of Campomanesia aurea against three strains of Listeria monocytogenes / Caracterização química e atividade antimicrobiana de Campomanesia aurea contra três cepas de Listeria monocytogenes

Abstract The essential oil (EO) composition of leaves of Campomanesia aurea was analyzed by GC-MS. The plant was collected in April (EOA) and October (EOO) in São Francisco de Assis/RS. The essential oils were obtained by hydrodistillation in a modified Clevenger apparatus. The yields were 4.44% in April, and 6.15%, in October. Thirty-one compounds were identified in EOA, accounting for 96.87% of the total, and twenty-eight compounds were identified in EOO, accounting for 99.46% of the total. For EOA, the major identified monoterpene was p-cymene (8.33%) and the major identified sesquiterpene was α-cadinol (10.72%), while regarding EOO the major identified monoterpene was repeatedly Terpinolene (3.43%), whereas the major identified sesquiterpene was α-cadinol (12.79%). The antibacterial activity of the essential oil was evaluated against the three Listeria monocytogenes from the American Type Culture Collection (strains ATCC 7644, 19114 and 13932). The essential oil showed a MIC of 10 mg/mL against the strains ATCC 7644 and 19114, with bacteriostatic effect of 20 mg/mL and a MIC of 20 mg/mL for ATCC 13932. Regarding the antibiofilm activity, o EOO showed the best results with an inhibition of 90% in the sessile growth with an applied concentration of 4.0 mg/mL.

Resumo O óleo essencial (EO) das folhas de Campomanesia aurea foi analisado por CG-EM. O A planta foi coletada em abril (OEA) e outubro (OEO) em São Francisco de Assis/RS. Os óleos essenciais foram obtidos por hidrodestilação em aparelho Clevenger modificado. Os rendimentos foram de 4,44% em abril e 6,15% em outubro. Trinta e um compostos foram identificados no EOA, representando 96,87% do total, e vinte e oito compostos foram identificados no EOO, representando 99,46% do total. Para EOA, o principal monoterpeno identificado foi o p-cimeno (8,33%) e o principal sesquiterpeno identificado foi o α-candinol (10,72%), enquanto o EOO o maior monoterpeno identificado foi repetidamente Terpinolene (3,43%), enquanto o sesquiterpeno principal identificado foi α-cadinol (12,79%). A atividade antibacteriana do óleo essencial foi avaliada contra as três cepas de Listeria monocytogenes obtidas a partir da American Type Culture Collection (isolados ATCC 7644, 19114 and 13932). O óleo essencial apresentou uma CIM de 10 mg/mL contra as cepas ATCC 7644. e 19114, com efeito bacteriostático de 20 mg/mL e MIC de 20 mg/mL para ATCC 13932. Quanto à atividade antibiofilme, o EOO apresentou os melhores resultados com uma inibição de 90% no crescimento séssil com uma concentração aplicada de 4,0 mg/mL.

Anatomical variations in cervical vertebrae in two species of neotropical canids: What is the meaning?

Anatomical variation in wild canids is rarely described. Altered shapes, uni- or bilaterally situated, were observed in ventral laminae of C6 and/or in C7 vertebral body of two fox species: Lycalopex gymnocercus and Cerdocyon thous. The specimens were young adults, collected dead on highways in southern Brazil. Deformities were considered anatomical variations because apparently there was no interference in function. The occurrence of such variations in two related species from the same area can suggest an environmental common cause rather than genetic issues. Future studies may deepen the understanding between cause and effect of these vertebral deformities in wild canids.

Extraction and characterization of phytochemical compounds from araçazeiro (Psidium cattleianum) leaf: Putative antioxidant and antimicrobial properties.

Underexplored species have phytochemical potential for pharmacological and nutraceutical applications. The fruits of such species, including aracá (Psidium cattleianum Sabine), are rich in specialized metabolites with putative antioxidant and antimicrobial activity; therefore, the leaves of these species are also a potential source of bioactive compounds. In this study, araçazeiro leaves were extracted using an aqueous infusion (Al) and a pressurized liquid extraction system with water (PLE-W), ethanol (PLE-E), and 1:1 water:ethanol ratio combination (PLE-W:E). PLE-W:E yielded a greater diversity of extracted compounds. Nonetheless, all extracts showed inhibitory activity against pathogenic Gram-positive and Gram-negative bacteria and antioxidant activity in the in vitro thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS) assays with rat brain and yeast model systems. Thus, araçazeiro leaves can be exploited as a promising source of bioactive compounds.

Detection of Bartonella sp. and a novel spotted fever group Rickettsia sp. in Neotropical fleas of wild rodents (Cricetidae) from Southern Brazil.

The Neotropical region shows a great diversity of fleas, comprising more than 50 genera. The importance of the study of fleas is linked to their potential role as disease vectors. The aim of this study is to investigate the presence of Rickettsia spp. and Bartonella spp. in Neotropical fleas collected from wild rodents in Southern Brazil. From 350 rodents captured, 30 were parasitized by fleas. A total of 61 fleas belonging to two genera and six different species were collected (Craneopsylla minerva minerva, Polygenis occidentalis occidentalis, Polygenis platensis, Polygenis pradoi, Polygenis rimatus, and Polygenis roberti roberti). In 13 % of fleas of three different species (C. minerva, P. platensis, and P. pradoi) Rickettsia sp. DNA was found. Phylogenetic analysis of concatenated sequences of gltA, htrA, and ompA genes showed that Rickettsia sp. found in rodent fleas (referred as strain Taim) grouped together with Spotted Fever Group Rickettsia. In reference to Bartonella spp., five genotypes were identified in seven fleas of two species (C. minerva and P. platensis) and in five rodent spleens. Also, 207 frozen samples of wild rodents were screened for these pathogens: while none was positive for Rickettsia spp.; five rodent spleens were PCR-positive for Bartonella spp.. Herein, we show the detection of potential novel variants of Bartonella sp. and Rickettsia sp. in fleas collected of wild rodents from Southern Brazil. Further studies are needed to fully characterize these microorganisms, as well as to improve the knowledge on the potential role of Neotropical flea species as diseases vectors.

Multidrug Resistance in Enterococci Isolated From Wild Pampas Foxes (Lycalopex gymnocercus) and Geoffroy's Cats (Leopardus geoffroyi) in the Brazilian Pampa Biome.

Enterococci are ubiquitous microorganisms present in various environments and within the gastrointestinal tracts of humans and other animals. Notably, fecal enterococci are suitable indicators for monitoring antimicrobial resistance dissemination. Resistant bacterial strains recovered from the fecal samples of wild animals can highlight important aspects of environmental disturbances. In this report, we investigated antimicrobial susceptibility as well as resistance and virulence genes in fecal enterococci isolated from wild Pampas foxes (Lycalopex gymnocercus) (n = 5) and Geoffroy's cats (Leopardus geoffroyi) (n = 4) in the Brazilian Pampa biome. Enterococci were isolated from eight out of nine fecal samples and Enterococcus faecalis was identified in both animals. However, E. faecium and E. durans were only detected in Pampas foxes, while E. hirae was only detected in Geoffroy's cats. Antimicrobial susceptibility analysis showed resistance to rifampicin (94%), erythromycin (72.6%), ciprofloxacin/norfloxacin (40%), streptomycin (38%), and tetracycline (26%). The high frequency of multidrug-resistant enterococci (66%) isolated in this study is a matter of concern since these are wild animals with no history of therapeutic antibiotic exposure. The tetM/tetL and msrC/ermB genes were detected in most tetracycline- and erythromycin-resistant enterococci, respectively. The gelE, ace, agg, esp, and clyA virulence genes were also detected in enterococci. In conclusion, our data suggest that habitat fragmentation and anthropogenic activities in the Pampa biome may contribute to high frequencies of multidrug-resistant enterococci in the gut communities of wild Pampas foxes and Geoffroy's cats. To the best of the authors' knowledge, this is the first report of antimicrobial-resistant enterococci in the Pampa biome.

Heifers rearing on natural grassland under rotational grazing during warm season / Recria de novilhas em pastagem natural sob pastoreio rotativo na primavera-verão

ABSTRACT: This study aimed to evaluate the effect of two rest intervals between grazing on the structural characteristics of pasture and performance of beef heifers in Campos grassland under rotational grazing. The treatments were two intervals between 375 and 750 DD (degree-days) grazing, based on the cumulative thermal sum for leaf expansion of native grasses belonging to capture and conservation groups of resources dominant in a natural grassland. The experiment was conducted during 151 days from October 2015 to March 2016, and twenty-four Braford heifers tests mean age = 12 months; mean body weight = 220kg (± 27.8) were used. The pre-grazing total forage mass (FMt) was on average 3791 kgMSha-1 and did not differ between treatments and season, the same occurred with the non-tussock FM. The average stocking rate was 469 kg ha-1 in both treatments. The average daily gain varied only between seasons, 0.102 kg animal-1 day-1 during spring and 0.372 kg animal-1 day-1 during summer. During the 151 evaluation days, the gain per area was a 103 kgha-1. The use of rest intervals between grazing based on the leaf elongation of dominant grasses, when applied to the areas of Campos grasslands, provided nutritional conditions to reach the target body weight for breeding 24 months old beef heifers.

RESUMO: O estudo objetivou avaliar o efeito de dois intervalos de descanso entre pastoreios nas características estruturais do pasto e desempenho de novilhas de corte em pastagens naturais manejadas em pastejo rotativo. Os tratamentos foram dois intervalos entre pastejos de 375 e 750 GD (graus dia), baseados na soma térmica da duração de elongação foliar média de gramíneas de grupos de captura e conservação dos recursos dominantes de uma pastagem natural. O experimento foi conduzido no período de outubro de 2015 a março de 2016, com duração de 151 dias e os períodos experimentais divididos em primavera e verão. Foram utilizadas 24 novilhas teste da raça Braford, com idade inicial na média de 12 meses, e de peso corporal médio de 220 kg (± 27,8). A Massa de forragem total (FMt) pré-pastejo foi em média de 3791 kgMSha-1 e não diferiu entre tratamentos e estação, o mesmo ocorreu com a FM de estrato não touceira. A taxa de lotação média foi de 469 kgha-1 em ambos os tratamentos. O ganho médio diário variou apenas entre estações, com médias de 0,102 kganimal-1dia-1 na primavera e 0,372 kganimal-1dia-1 no verão. O ganho por área durante os 151 dias de avaliação foi em média de 103 kgha-1. As pastagens naturais submetidas a intervalos de descanso entre pastoreios baseados na elongação foliar de gramíneas dominantes, independente do tratamento utilizado, proporcionam ritmos de ganhos médios diários compatíveis com a meta de peso corporal, a ser atingida aos 24 meses, para que as novilhas possam ser acasaladas.

Bacterial and Archaeal Communities Change With Intensity of Vegetation Coverage in Arenized Soils From the Pampa Biome.

Arenization occurs in regions that present sandy soils with normal rainfall levels. Predatory use of environmental sources, the dissolution of arenitic rocks and reworking of non-consolidated surface sands intensify this degradation scenario. Thus, this work aimed to evaluate the impact of the arenization process in the Brazilian Pampa Biome and how this phenomenon affects the soil microbial and plant communities. For this purpose, three arenized areas in Southern Brazil (Pampa Biome) were selected and, in each one, three sampling points were studied: arenized (ARA), arenized to grassland transition (AGT), and grassland (GRA) areas. In the three sampling points, soils presented low levels of nutrients, organic matter, mud and pH acidic in all regions but, the presence of vegetation coverage in AGT and GRA areas preserved the topsoil structure. Our study related ARA with bacterial families Alcaligenaceae, Pseudomonadaceae, and Xanthomonadaceae. AGT with bacterial families Bacillaceae and Burkholderiaceae, and plant species Melinis repens (Willd.) Zizka and Paspalum stellatum Humb. and Bonpl. ex Flüggé, and GRA with bacterial families Koribacteraceae, Hyphomicrobiaceae, and Chthoniobacteraceae, and plant species Croton subpannosus Müll.Arg. ex Griseb., Piptochaetium montevidense (Spreng.) Parodi and Elyonurus sp. The three studied areas (as well as sampling points) present soils extremely poor in nutrients with sandy texture, and the bacterial and plant composition well known to be resistant to environmental stresses were dominant. The vulnerability of these areas causes a degradation scenario, which is worsened by agricultural activities. However, in general, this phenomenon is a natural process that occurs mainly due to soil characteristics (poor soils) and climatic variations.

Phylogeography Approach of Diloboderus abderus (Coleoptera: Melolonthidae) in the Southern Cone of America.

Diloboderus abderus (Sturm, 1826) (Coleoptera: Melolonthidae) is a serious soil pest of corn, wheat, oat, and natural and cultivated pastures in Argentina, Paraguay, Uruguay, and southern Brazil. Despite its economic importance, the genetic diversity and population structure of D. abderus remain unknown. We sequenced a fragment of the mitochondrial gene cytochrome oxidase I region (COI), of six populations of D. abderus from the Southern Cone of America. The mtDNA marker revealed a high haplotype diversity, high pairwise FST values, and significant genetic variations among populations. No correlation was found between genetic and geographical distances, yet the most common haplotype (Dab01) was present in four out of the six populations. Analysis of molecular variance showed that most of the variation was within populations of D. abderus. Tajima's D and Fu's FS tests indicated no evidence that D. abderus populations are under recent expansion. Our results indicate that genetic-based traits will likely remain localized or spread slowly, and management strategies need to be undertaken on a small scale.

Clonal cleaning and in vitro multiplication of Angelonia integerrima sprengel / Limpeza clonal e multiplicação in vitro de Angelonia integerrima sprengel

The objective of this study is to test stem apex sizes in the in vitro establishing of Angelonia integerrima in order to obtain explants without by fungi and bacteria contamination for further multiplications. The treatments consisted of different stem apex sizes (1.0, 3.0, 5.0, 7.0, 9.0 and 11.0 mm). At 45 and 90 days of cultivation, a count of contaminated explants and a count of shoots per explant formed were performed. In a second experiment, explants were cultivated in a medium containing different concentrations of benzylaminopurine (BAP) (0.0, 0.05, 0.10, 0.15 and 0.20 mg L-1). After 56 days of cultivation, the following variables were evaluated: shoot length, shoot fresh mass and number of shoots. During the explant establishment phase (45 days), only stem apexes with 1.0 mm in size were not contaminated. However, in the second subculture (at 90 days), only shoots from initial explants, with 7 mm in size or larger, were contaminated. Regarding multiplication, the presence of BAP showed a positive linear behavior for all variables. It is possible to obtain A. integerrima seedlings free of contamination in vitro by fungi and bacteria, using initial explants less than or equal to 5 mm. IBA provided a linear increment for the multiplication of this species.

O objetivo do trabalho foi testar tamanhos de ápices caulinares no estabelecimento in vitro de Angelonia integerrima, a fim de obter explantes sem contaminações por fungos e bactérias para posterior multiplicação. Os tratamentos consistiram de tamanhos de ápices caulinares: 1,0; 3,0; 5,0; 7,0; 9,0 e 11,0 mm. Após 45 e 90 dias de cultivo foi realizada a contagem de explantes contaminados e o número de brotos formados por explante. Em um segundo experimento, explantes foram cultivados em meio contendo diferentes concentrações de benzilaminopurina (BAP): 0,0; 0,05; 0,10; 0,15 e 0,20 mg L-1. Após 56 dias de cultivo foram avaliados: comprimento e massa fresca da parte aérea e número de brotos. Durante a fase de estabelecimento (45 dias), somente explantes com 1,0 mm não apresentaram contaminação, já no segundo subcultivo (aos 90 dias) somente brotações oriundas de explantes com tamanho inicial igual ou superior a 7 mm apresentaram contaminação. Com relação à multiplicação, a presença de BAP apresentou comportamento linear positivo para todas as variáveis analisadas. É possível obter mudas de A. integerrima livres de contaminações in vitro por fungos e bactérias, utilizando explantes iniciais menores ou iguais a 5 mm. O BAP proporcionou incremento linear para a multiplicação da espécie.

Effects of model-mimic frequency on insect visitation and plant reproduction in a self-mimicry pollination system.

The proportion of mimics and models is a key parameter in mimetic systems. In monoecious plants with self-mimicry pollination systems, the mimic-model ratio is determined by the floral sex ratio. While an equal sex ratio (1:1) could provide the perfect balance between pollen donors and stigma surfaces able to receive the pollen, an unequal ratio could increase pollination by production of a greater number of rewarding, model flowers. The aim of the present study is to test the differences in visitation frequency and reproductive rates of different mimic and model flower arrays in order to assess the efficacy of the mimetic system in a Begonia cucullata population. The frequencies of visitors to groups of flowers with three distinctive sex ratio arrays (male-biased, female-biased and equal ratio) were compared using a Bayesian approach. The reproductive outcomes were compared in order to detect advantages of particular sex ratios. Low visitation frequency was recorded in all arrays. Pollinators showed similar behaviour regardless of sex ratio; they tended to avoid female, rewardless flowers. Pollination quality was highest in the equal sex ratio array. The current study shows that sex ratio plays a critical role in the pollination of B. cucullata and that the efficacy of the self-mimicry system appears to be doubtful. Visitation frequency may be associated with visual or chemical cues that allow pollinators to recognize models and mimics, regardless of their frequency in the population.

Diversity of Drosophilidae (Insecta, Diptera) in the Restinga forest of southern Brazil

Abstract Although members of Drosophilidae are frequently the topic of ecological studies in Brazil, few have explored Restinga or, until only recently, Pampa biome environments. This study proposes to describe the diversity and temporal variation of the Drosophilidae assemblage from a Restinga forest of Rio Grande do Sul, Brazil. We performed monthly collections from February 2013 to January 2014 using yeasted banana-baited traps. A total of 25,093 individuals of 46 species were sampled. Drosophila simulans and the D. willistoni subgroup were the dominant taxa; D. polymorpha, D. immigrans, D. paraguayensis and Zygothrica orbitalis were of intermediate abundance, and the other 40 species were rare. Based on sampling effort estimators, our collections were sufficient. Jaccard and Morisita indices evaluated using ANOSIM reveal little similarity in the composition of samples across months. Canonical correspondence analysis shows that the variables of maximum and minimum temperature are the main factors responsible for differentiation of the species composition of the assemblage throughout the year, whereby collections in the coldest periods (July, August and September) are those with a more differentiated composition. In these months, the dominance of D. simulans and the D. willistoni subgroup decreases while increased abundance of the D. tripunctata group (as D. paraguayensis) and Z. orbitalis occurs. In comparison to other studies carried out in environments in southernmost Brazil, we observed a similar pattern of fluctuation in abundance over the year, with a higher abundance of dominant species in warmer months and population sizes decreasing in colder months.

Population Genetic Structure of Cnesterodon decemmaculatus (Poeciliidae): A Freshwater Look at the Pampa Biome in Southern South America.

The Pampas is a Neotropical biome formed primarily by low altitude grasslands and encompasses the southernmost portion of Brazil, Uruguay, and part of Argentina. Despite the high level of endemism, and its significant environmental heterogeneity, Pampean species are underrepresented in phylogeographic studies, especially aquatic organisms. The Pampean hydrological system resulted from a long history of tectonism, climate, and sea level changes since the Neogene. In this study, we examined the population genetic structure of Cnesterodon decemmaculatus, a freshwater fish species that occurs throughout most of the Pampa biome. We characterized mitochondrial and autosomal genetic lineages in populations sampled from Southern Brazil and Uruguay to investigate (1) the correspondence between current drainage systems and evolutionary lineages, (2) the demographic history for each genetic lineage, and (3) the temporal depth of these lineages. Overall, we found that the major evolutionary lineages in this species are strongly related to the main Pampean drainage systems, even though stream capture events may have affected the distribution of genetic lineages among drainages. There was evidence for recent population growth in the lineages occupying drainages closest to the shore, which may indicate the effect of quaternary sea-level changes. In general, divergence time estimates among evolutionary lineages were shallow, ranging from 20,000 to 800,000 years before present, indicating a geologically recent history for this group, as previously reported in other Pampean species. A Bayesian phylogeographical reconstruction suggested that an ancestral lineage probably colonized the Uruguay River Basin, and then expanded throughout the Pampas. This evolutionary scenario may represent useful starting models for other freshwater species having a similar distribution.

A new species of Ituglanis (Siluriformes: Trichomycteridae) from the rio Uruguai basin, southern Brazil

A new species of Ituglanis associated to the grasslands of the Pampa biome is described from the rio Uruguai basin, southern Brazil. The new species is distinguished from its congeners by the low number of ribs and by a unique color pattern composed of an outer layer with scattered round black blotches equivalent in size to the eye circumference over a reddish brown background on the lateral surface of the body. We provide the genetic sequences of the mitochondrial gene Cytochrome c Oxydase subunit I (COI) for three of the paratypes and discuss aspects about the recent discovery of the new species.(AU)

Uma nova espécie de Ituglanis, associada aos campos do bioma Pampa, é descrita para a bacia do rio Uruguai no sul do Brasil. A nova espécie distingue-se de todos seus congêneres pelo pequeno número de costelas e por um padrão de coloração único que consiste de manchas pretas arredondadas de tamanho equivalente à circunferência do olho sobre um fundo marrom avermelhado na superfície lateral do corpo. Sequências genéticas do gene mitocondrial Citocromo Oxidase subunidade I (COI) para três dos parátipos são fornecidas, e aspectos sobre a recente descoberta da nova espécie são discutidos.(AU)

Chemical characterization and antimicrobial activity of Campomanesia aurea against three strains of Listeria monocytogenes

Abstract The essential oil (EO) composition of leaves of Campomanesia aurea was analyzed by GC-MS. The plant was collected in April (EOA) and October (EOO) in São Francisco de Assis/RS. The essential oils were obtained by hydrodistillation in a modified Clevenger apparatus. The yields were 4.44% in April, and 6.15%, in October. Thirty-one compounds were identified in EOA, accounting for 96.87% of the total, and twenty-eight compounds were identified in EOO, accounting for 99.46% of the total. For EOA, the major identified monoterpene was p-cymene (8.33%) and the major identified sesquiterpene was -cadinol (10.72%), while regarding EOO the major identified monoterpene was repeatedly Terpinolene (3.43%), whereas the major identified sesquiterpene was -cadinol (12.79%). The antibacterial activity of the essential oil was evaluated against the three Listeria monocytogenes from the American Type Culture Collection (strains ATCC 7644, 19114 and 13932). The essential oil showed a MIC of 10 mg/mL against the strains ATCC 7644 and 19114, with bacteriostatic effect of 20 mg/mL and a MIC of 20 mg/mL for ATCC 13932. Regarding the antibiofilm activity, o EOO showed the best results with an inhibition of 90% in the sessile growth with an applied concentration of 4.0 mg/mL.

Resumo O óleo essencial (EO) das folhas de Campomanesia aurea foi analisado por CG-EM. O A planta foi coletada em abril (OEA) e outubro (OEO) em São Francisco de Assis/RS. Os óleos essenciais foram obtidos por hidrodestilação em aparelho Clevenger modificado. Os rendimentos foram de 4,44% em abril e 6,15% em outubro. Trinta e um compostos foram identificados no EOA, representando 96,87% do total, e vinte e oito compostos foram identificados no EOO, representando 99,46% do total. Para EOA, o principal monoterpeno identificado foi o p-cimeno (8,33%) e o principal sesquiterpeno identificado foi o -candinol (10,72%), enquanto o EOO o maior monoterpeno identificado foi repetidamente Terpinolene (3,43%), enquanto o sesquiterpeno principal identificado foi -cadinol (12,79%). A atividade antibacteriana do óleo essencial foi avaliada contra as três cepas de Listeria monocytogenes obtidas a partir da American Type Culture Collection (isolados ATCC 7644, 19114 and 13932). O óleo essencial apresentou uma CIM de 10 mg/mL contra as cepas ATCC 7644. e 19114, com efeito bacteriostático de 20 mg/mL e MIC de 20 mg/mL para ATCC 13932. Quanto à atividade antibiofilme, o EOO apresentou os melhores resultados com uma inibição de 90% no crescimento séssil com uma concentração aplicada de 4,0 mg/mL.