Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The invasion of the sailfin catfish has caused serious ecological and socio-economic problems in various global ecosystems. This study evaluates the impact of this invasive species in the Champayán Lagoon System, considering both ecological and socioeconomic aspects as well as and the perception of local fishermen. Semi-structured interviews were conducted to gather information on socio-economic conditions and the perception of the devil fish's impact. The results reveal that fishermen report a high abundance of devil fish, associated with a notable decrease in the catch of commercial fish. Additionally, alterations in the habitat (water quality and erosion), damage to fishing gear, and negative effects such as physical injuries and mental stress in fishermen were identified. These findings highlight the urgent need to develop and implement management and control strategies to mitigate the impact of this invasive species and improve the quality of life of the inhabitants of the affected fishing communities.

In vitro maturation of oocytes is a crucial process for in vitro production of embryos, a technology that still presents challenges to reach its full potential. The objective was to evaluate the addition of α-tocopherol during in vitro oocyte maturation and its subsequent effect on embryo development. A total of 1,019 bovine oocytes were used, classified as high and low quality, supplemented with ethanol and α-tocopherol at 100, 200, and 400 µM/mL during in vitro maturation, measuring maturation rates, cleavage, blastulation, and blastocyst expansion. Maturation was higher in high-quality oocytes (p < 0.01). Cleavage rate and percentage of expanded blastocysts were higher in embryos from high-quality oocytes (HQOE) supplemented with 400 μM/mL (p < 0.05). Blastulation rate was lower in HQOE supplemented with ethanol and 100 µM/mL (p < 0.05). In conclusion, high-quality oocytes exhibited higher maturation and embryo development rates compared to low-quality ones. α-tocopherol at 400 μM/mL increased cleavage and expanded blastocyst rates in HQOE. Ethanol reduced blastulation in HQOE, which was mitigated by the addition of 200 and 400 μM/mL of α-tocopherol.

The pigments of Cosmos bipinnatus were characterized for their possible application as natural dyes. In the extraction of the pigments, three solvents were evaluated, being the combination of water and ethanol the one that presented the best results. Subsequently, the stability of the pigments was evaluated under different conditions of pH, temperature and light radiation during 41 days of storage. Analysis of the degradation kinetics of anthocyanins indicated a first order reaction and a half-life of 0.7 to 63 days. At the end of storage, polymeric color formation increased by pH effect (1.6 - 96.2%) while anthocyanin concentration decreased by temperature effect (1.1 to 0 mg cyn-3-glu g-1). Antioxidant activity was affected by storage conditions, decreasing from 251 mg ET g-1 to 69 mg ET g-1. Regarding color, it was preserved longer at pH 4, unlike the samples at pH 10 and 7. According to the results, it is suggested to use the extract of Cosmos bipinnatus flowers at pH 4, in foods whose processing and storage is carried out at refrigeration temperature.

Moringa oleifera is a species with a wide global distribution due to its adaptive capacity and nutritional properties. In Mexico, there have been several reintroductions of this species and although morphological diversity has been observed, the extent of its diversity at the DNA level is unknown. The objective was to determine the diversity and genetic structure of 14 populations of M. oleifera cultivated in Mexico through SNP. The seeds were germinated in a greenhouse and DNA was extracted from young leaves and stems using a CTAB-based protocol. This DNA was used to genotype each population with DArTseqTM technology. 9,862 SNPs were obtained, of which 0.64% were polymorphic. Moderate levels of diversity were observed within the populations (Ae=1.52, He=0.33, Ho= 0.44, Shannon index = 0.44). The genetic background of the populations allowed two groups to be visualized through cluster analysis and PCoA. The genetic structure of the populations using STRUCTURE indicated that the ancestry comes from two original populations (K = 2). The 14 moringa populations are diverse at the high-quality DNA level for accurate and reliable sequencing.

Macrophomina phaseolina (Tassi) Goid is a pathogen that causes damping off, stem rot and root rot disease in a broad host range. The method of biological control using bacteria of the genus Bacillus stands out as viable and effective in combating plant diseases. The aim of the present study was detecting the presence of enzymatic compounds produced by the Bacillus isolates and evaluating the in vitro antagonistic activity of the bacterial isolates against M. phaseolina, using the methods of paired culture, pathogen culture on antagonist culture, thermostable and volatile metabolites. The experiments were carried out at the Phytopathology Laboratory, Department of Technology and Social Science, Campus III – UNEB, in Juazeiro-BA. Of the nine Bacillus isolates provided by the LBM, all were molecularly identified, except for isolate B7. The fungus M. phaseolina was acquired from the Dept. of Micologia at Federal University of Pernambuco. The experiment was in a completely randomized design for the enzymatic test using three replicates, and for the antagonism studies a 4x5 factorial arrangement was used (four isolates and four methods of antagonistic activity and the control treatment) with five replicates. Data were subjected to analysis of variance and Scott-Knott test at 5% probability. The enzymes showed the rates: proteases (100 %), cellulases (88%), pectinases (77 %), and amylases (66 %), suggesting that the isolates could be promising in the biological control of pathogens. In the selection of isolates with greater antagonistic activity, the method of culturing the pathogen on the culture, proved to be the most efficient in inhibiting the growth of M. phaseolina.

Due to their high dry matter production and balanced nutritive value per unit area, Elephant grass cultivars are excellent for bulky supplementation during the dry season. The objective was to evaluate the productivity and nutritive value of the BRS Capiaçu cultivar through different cutting ages after planting. The experimental design was conducted in completely randomized blocks, with four cutting ages: 60, 90, 120, and 150 days, each with five replications (blocks), totaling 20 experimental units, covering a total area of 12 m². As age advanced, linear increases in productivity were observed (p≤0.01), reaching an average height of 4.60 m, a green matter productivity of 252.60 t·ha-1, and a dry matter productivity of 67.36 t·ha-1 at 150 days after planting. Regarding nutritional value, linear increments (p≤0.01) were found in dry matter, organic matter, and neutral detergent fiber levels, while mineral matter and crude protein exhibited a linear reduction (p≤0.01). However, no effects (p>0.17) were observed with advancing cutting age after planting for acid detergent fiber, and hemicellulose variables. It is concluded that increasing the cutting age reduces the forage's nutritional value. From this perspective, the 90-day age proved to be more suitable for cutting BRS Capiaçu elephant grass.

Blackberries are a key source of income for many families, including small and medium-sized producers in Ecuador. There has been a growing need to contribute to research on controlling a disease, powdery mildew, that has been causing significant production losses in recent years. The country has approximately 5,000 hectares of blackberry crops, involving around 15,000 producers in the Ecuadorian highlands. This research was conducted to evaluate the chemical control of powdery mildew (Oidium sp.) in blackberry (Rubus glaucus) using participatory research.  A completely randomized block design was used with 3 treatments, 3 repetitions at each parcel of seven participant farmers. Three fungicide molecules were tested: Accord (difenoconazole), Sulflox (micronized sulfur), and ZT (hydrogen peroxide–27 %). The applications of fungicides were carried out two times and incidence and severity data were taken at 5 and 15 days. For yield, blackberries were counted and weighted. Initial and final surveys to farmers were carried out, accompanied by training.  Analysis of variance and Tukey's test (a = 0.05) were done for incidence, severity, and yield. Participatory research was detailed by means of previous knowledge and the assimilation of chemical treatment for powdery mildew. The best product for control of powdery mildew in all localities was Accord (difenoconazole). San José location had the best control of incidence (15.7 %). Farmers successfully complied with re-entry period in their orchards, in addition to adding Accord to their chemical control of powdery mildew.

The control of phytopathogens using plant extracts has been identified as an alternative to organic agriculture, which excludes the use of toxic and synthetic substances. The present study aimed to evaluate the sanitary and physiological potential of organic maize seeds treated with cambuci extract (Campomanesia phaea). Two plant extracts were tested, obtained from different tissues of the C. phaea species (fruit peel and leaf, fresh and dry), in the following concentrations: 0, 25, 50, 75 and 1000 %. The content of total phenolic compounds was found to be higher in the leaf extract (at 100 % concentration was 409.7 % higher in the leaf compared to the peel), particularly when prepared with fresh tissue. The dry peel extract was observed to increase the percentage and speed index of maize seed germination, without, affecting the biometric variables of the seedlings. Extracts from fresh cambuci leaves demonstrated a reduction in the percentage of fungi of the genus Fusarium. However, at a concentration of 50%, a phytotoxic effect of this extract on maize seeds was observed, which resulted in a reduction in germination and the length and dry mass of the seedlings. Our findings suggest that cambuci extract represents a promising strategy in the ecologically correct treatment of organic maize seeds, provided if it is applied at the appropriate concentration.

Phosphorus (P) deficiency in acid soils in Venezuela is frequent, to achieve good crop production farmers applied high-cost phosphate fertilizers. The use of phosphate rock as a source of P is an alternative, but it has low solubility and slow release of available P. The objective of this work was to identify bacteria capable to solubilizing Riecito and Navay phosphate rocks and release P. A total of 26 strains collected in different places in the country were used to find out the amount of P released into the medium by the action of the strains, and 14 of which were used to measure bacterial growth at different times, according their optical density. An in vitro experiment was carried out using 100 µL of concentrated bacterial suspension in 10 mL of NBRIP culture medium under sterile conditions. The sources of P were: tricalcium phosphate (FTC), Navay phosphate rock (RFN)) and Riecito phosphate rock (RFR) and 0P, plus the non-inoculated controls. The highest values of P, in µg.mL-1 corresponded to the FTC with 320 to 500 followed by RFN with 133 to 210 and RFR between 62 and 73. Strains G166, La37-26 and Ar146 showed the lowest pH levels in the growth media enriched with RFN and RFR and corresponded to the highest levels of solubilized phosphorus. This behavior demonstrates that bacteria with higher acidification capacity are potentially more effective in solubilizing unavailable P from phosphate rocks.