This study evaluates the potential of the flat oyster Isognomon alatus as a biomonitor species for metal contamination, based on bioaccumulation patterns in adults and juveniles present in the Seaflower Biosphere Reserve on San Andrés Island (Colombia) in three seasons climatic. The analysis by Atomic Absorption Spectrometry of I. alatus specimens and water samples collected in SAI (2009 and 2010) allowed us to observe higher concentrations (Max: 2,235 µg/g dry weight) of Zn in seston, compared to Cd (Max: 0.078 µg/g dry weight) and Cu (Max: 0.069 µg/g dry weight). These concentrations varied seasonally in relation to the intensity of rainfall in the area. By means of a two-way ANOVA (p<0.05), statistically significant differences were determined between sampling sites and seasons for metal concentrations (Cd, Cu, Zn) in organisms and for the Bioconcentration Factor (BCF), which corresponds to the relationship between the metal concentration in oysters and seston. Regarding the effect of age/size, the Cd concentration obtained and evaluated by ranges in juveniles is significantly lower than that observed in adults during the dry season, like what was recorded in other oyster studies. A comparison of the results obtained with the available data for I. alatus indicated that SAI had been impacted by Zn contamination. The results confirm the bioavailability of Cd previously reported; and the bioaccumulation of metals, especially Cu and Zn, according to FBC estimates.

Pig farming plays an important role in the Brazilian economy, but it may trigger environmental issues, especially regarding the contamination of water resources. In this study, we evaluated the effects of the deposition of effluents from a pig farm on the phytoplankton assemblage composition and limnological parameters at different spots of the Divisa River - Fazenda São Luís, Aparecida de Minas/MG, Brazil. Over six months, we analyzed several variables at three different sampling sites on the surface of a coastal zone. We registered seventy-four phytoplankton genera, with Chlorophyceae and Cyanophyceae representing the most abundant classes, and Cryptophyceae and Cyanophyceae displaying the highest densities. The PERMANOVA analysis revealed dissimilarity between sampling sites P1 x P3 and P2 x P3, and the SIMPER analysis showed that Cryptophyceae and Cyanophyceae contributed to the observed dissimilarity. The correspondence canonical analysis (CCA) allowed the organization of sampled sites in three groups, in which the phytoplankton composition was distinguished according to trophic gradients. We concluded that pig farming effluents discharged without previous treatment into water bodies exert influences in both the phytoplankton community and the dynamics of its assemblage, by increasing total phosphorus and contributing for increased abundances of Cryptophyceae and Cyanophyceae in the last evaluated site (P3).

Boana caiapo is a hylid treefrog with occurrence in the states of Goiás, Mato Grosso, Pará and Tocantins. We update on B. caiapo distribution for Mato Grosso state, Brazilian Cerrado (Neotropical Savana). The record extends its known distribution in approximately 330 km Northwest from the type locality (Aragarças municipality, Goiás) and 263 km Northwest from the nearest known locality (Cocalinho municipality, Mato Grosso state). All localities belong to the Tocantins-Araguaia River basin, reinforcing the restricted distribution of this species. Studies that related new records of species are important to direct conservation proposals.

Evaluating several biodiversity descriptors and considering several spatial scales might elucidate conservation issues and improve biodiversity monitoring in urban environments. We estimated species richness (order q = 0), Shannon diversity (order q = 1), and Simpson diversity (order q = 2) based on Hill numbers and performed cluster analysis and non-metric multidimensional scaling (NMDS) to compare seven urban micro-watersheds and a peri-urban site across a northern Andean city (Medellín, Colombia). We found 113 diurnal resident bird species: 50 (44 %) exclusively within urban sites, 21 (19 %) exclusively in the periurban site, and 42 (37 %) shared species. Some urban watersheds had similar bird species richness to the periurban site, but Shannon and Simpson diversities were always lower, showing decrease in local bird diversity when abundances were considered. Bird species composition differed between urban watersheds and the periurban site, with all urban watersheds grouped altogether by cluster and NMDS analysis, and the periurban site forming its own group. This suggests homogenization of bird species composition due to the species turnover decreasing across urban areas, with endemic, near endemic and rare species restricted to periurban areas where native forest remnants persist. Several scales of biodiversity and analysis at more local scales are needed to better understand biodiversity patterns across Andean cities and to design urban planning strategies that prevent biodiversity loss.

Complex traits are those whose inheritance does not follow simple and predictable patterns. They are not governed by a single locus, instead, they are determined by several loci and are influenced by the environment. Most of the traits with agronomic interest and economic importance such as resistance to biotic and abiotic stress, and yield, among others, are quantitative traits and their study is based on dissecting the underlying genetic architecture, the number of loci responsible for the variance of a quantitative trait, the relevant contribution made by each locus and their interaction with the environment. This review provides the most relevant conceptual bases for the study of the genetic architecture of complex quantitative traits in plants. The methodologies that allow identifying the loci and candidate genes that govern this type of traits are described, such as QTL mapping by linkage and association mapping. In addition, the incorporation of these loci in phenotype prediction strategies such as marker-assisted selection and genomic selection, exhibits the benefits and limitations of these approaches. Finally, the challenges and perspectives facing the study of the genetic architecture of complex traits in plants are discussed.

Mosquitoes represent the most important agent disseminating infectious diseases like yellow fever, dengue, chikungunya, and malaria, among others. An essential strategy for its control is killing them at immature stages using industrial insecticides. However, those chemicals often generate resistance and affect the environment and human health. Agricultural and plant by-products constitute a new sustainable option to obtain harmless and eco-friendly bioinsecticides to prevent mosquitoes from spreading. This study aimed to investigate the phytochemical profile of Persea americana Mill (Lauraceae) seed extracts and their insecticide activity against Aedes aegypti at larval and pupal stages. The ethanol extracts from avocado seeds were obtained by Maceration/stirring (MaE) and Soxhlet extraction (SE) methods. The main chemical profile was determined by quantitative and UPLC assays. Insecticide activity was assessed by the exposition of mosquitoes at larval and pupal stages to seed extracts. Human cell lines were used to evaluate the cytotoxicity. Soxhlet methodology was more efficient in the extraction of P. americana seeds metabolites (42.13±1.76 mg/mL) compared with MaE (20.46±1.66 mg/mL) (p< 0.05). Additionally, SE showed a higher amount of polyphenols (5.12±0.18 mg/mL). The UPLC spectra analysis revealed the presence of polyphenols, mainly catechin, and neolignan constituents. Both extracts showed larvicidal and pupicidal effects, but SE was more active at lower concentrations. Moreover, no significant toxic effects on human monocytes and fibroblast cell lines were found after treatment. In sum, avocado seed by-products can be considered an eco-friendly insecticide and its use may help to substantially decrease the vector-transmitted diseases in developing countries.

Meiofauna is a group of heterotrophic organisms smaller than macroinvertebrates but larger than microfauna and characterized by groups such as testate amoebae, ciliates, and nematodes. They are a link between bacteria and resources and macroinvertebrates. However, tropical meiofauna is poorly studied; thus, our goal was to characterize meiofaunal community composition and abundance and assess potential environmental variables controlling these community dynamics. Monthly samplings of meiofauna were conducted for eight months in Quebrada Prieta, El Yunque National Forest, Puerto Rico. Sampling was made in 12 pools, and data on discharge, sediment characteristics, and biotic variables were also collected. A total of 62 meiofaunal morphospecies were identified, with nematodes dominating the community, followed by testate amoebae. Bacterivores and detritivores taxa dominated the community. Meiofaunal abundance was negatively related to discharge and positively to the percentage of coarse sand, nitrate, and macroinvertebrate abundance. The composition of meiofauna in Quebrada Prieta is like the composition reported for temperate streams, at least in major meiofaunal groups present. However, the community in Quebrada Prieta was dominated by testate amoebae. In contrast, temperate streams are often dominated by rotifers and nematodes. Both abiotic and biotic variables are important for meiofaunal communities in the headwater streams in Puerto Rico.

Information on snake diet is scarce, being obtained from specimens deposited in scientific collections or through occasional records. Thamnodynastes species have a generalist diet, although predominantly batracophagus. Thamnodynastes phoenix is an endemic snake in Brazil, which was described recently, and little is known about its ecology. Herein, we report the first record of Hemidactylus agrius in the diet of T. phoenix in northeastern Brazil. Although there is a record of another lizard in its diet, this is the first record of a Gekkonidae as prey for this species. Studies on snake diet provide important information about natural history, contributing to the evolutionary biology and conservation of the species, which are still limited.

Water limitation is one of the main factors that influence the germination process, affecting crop establishment. Thus, alternatives capable of lessening such effects become of great relevance. The aim of this study was to evaluate the effect of ascorbic acid dosage on This study aimed of marandu grass seeds submitted to different water conditions. After establishing the immersion time for seed conditioning based on the soakingcurve, the experiment was conducted to evaluate the physiological potential, in a 3x5 factorial scheme, composed of three osmotic potentials (0; -0.2 and -0.4 MPa) and five ascorbic acid doses (0, 20, 40, 60 and 80 mM), with four repetitions. The germination, root protrusion, first germination count, germination speed index, root length and seedling shoots were evaluated. The physiological potential of the seeds was negatively affected by water stress induced by polyethylene glycol 6000, with deleterious effects on osmotic potentials -0.2 and -0.4 MPa. However, ascorbic acid conditioning at doses between 40 and 50 mM promoted improvements in seed germination performance and alleviated the harmful effects promoted by low water availability under the -0.2 MPa potential, stimulating tolerance to water stress. Improvements were also obtained in root and shoot growth of seedlings originated from seeds submitted to -0.4 MPa potential after conditioning.

The production and consumption of blueberry have increased in Mexico owing to its health benefits. Symbiotic relationships have been shown to be crucial in blueberry plants. In particular, phytohormone production by Pseudomonas fluorescens is an important mechanism of plant growth promotion. However, there are only a few reports on the effects of plant growth-promoting bacteria in blueberries. Therefore, we aimed to evaluate the effects of four strains of P. fluorescens (UM16, UM240, UM256, and UM270) and two types of slow-release fertilizer (nitrophosphate and basacote) on the development of blueberry var. Biloxi under greenhouse conditions. Blueberry seedlings obtained from in vitro culture and adapted under greenhouse conditions were inoculated with 1 x 106 CFU with any of the four strains, depending on treatment. Plants inoculated showed increased average plant length, plant fresh weight, root length, and root fresh and dry weight, compared with those with the control treatment (non-inoculated plants). The plants inoculated and fertilized with nitrophosphate had a better development compared with those fertilized with basacote or the control plants (inoculated or fertilized). Inoculated plants fertilized with nitrophosphate also had greater plant length, higher fresh plant weight, longer roots, and greater root fresh and dry weight than the control (non-inoculated or non-fertilized plants). Our study could facilitate the sustainable propagation of blueberry plants.