Principais Coleções do Repositório
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Seleção e atratividade de plantas medicinais para vespas sociais em sistema ecológico de cultivo
(Universidade Federal de Lavras, 2024-09-27) Noronha, Syara Cesario Bravo de; Carvalho, Geraldo Andrade; Silveira, Luís Cláudio Paterno; Carvalho, Geraldo Andrade; Silveira, Luís Cláudio Paterno; Carvalho, Alexandre Alves de; Jacques, Gabriel de Castro
In ecological planting systems, the application of pesticides is not performed, thereby promoting the maintenance of beneficial soil organisms, pollinators, and natural enemies. These systems utilize intercropping, including medicinal plants. Such plants perform biological functions, such as attracting pollinators and defending them against herbivores, due to their production of secondary metabolites, which can modulate the metabolism of other plants and insects. Integrated management strategies include the use of attractive plants that interfere with foraging behavior and the conservation of natural enemies, such as social wasps. Diverse cultivation can increase biodiversity, reduce the incidence of herbivorous insects, and maintain ecological balance. The present study aimed to develop a methodology for selecting potentially attractive medicinal plants for natural enemies to be cultivated in intercropping systems within ecological planting, focusing on conservative biological control and evaluating the attractiveness of medicinal plants to social wasps in an ecological environment. Scoring criteria were established for the pre-selected plants, considering favorable aspects and unfavorable characteristics, with each species assigned a positive, negative, or neutral score. The preliminary selection of plants for evaluation was based on local biodiversity, edaphoclimatic conditions, availability of plant species, and the presence of favorable metabolites. The methodology was applied, and the selected species were planted in 2022 and 2023 at the Agroecology Sector of IFSULDEMINAS, within the Atlantic Forest biome, characterized by Seasonal Semideciduous Forest physiognomy. The experiment included six treatments chosen from twenty medicinal species based on a literature review: Clinopodium sp. (Clinopodium); Lippia alba (Brazilian Lemon Balm); Petroselinum crispum (Parsley); Bidens pilosa (Black Jack); Coriandrum sativum (Coriander); and Tagetes erecta (Marigold), arranged in randomized blocks. Insects were collected weekly for nine weeks using an entomological net and pan traps and identified based on specific literature. Rarefaction curves, species richness (bootstrap and species), abundance, similarity, and variance analyses were conducted. For species richness, B. pilosa and L. alba exhibited the highest averages, significantly different from T. erecta and Clinopodium sp., while the other plant species showed intermediate richness averages. Significant differences were also observed for abundance, with the highest value recorded for B. pilosa, significantly different from T. erecta and Clinopodium sp., while the other plant species presented intermediate abundance values. Therefore, B. pilosa and L. alba are promising species for providing alternative resources to natural enemies when present in intercropping systems in ecological cultivation environments. The developed methodology can be adapted for other locations and objectives, depending on market interests and the areas of action of farmers and researchers. With the necessary adjustments, the methodology proved to be effective, as the highest-scoring plants were also the most attractive in the field.
Efeitos de uma multiprotease no desempenho, funcionalidade intestinal e digestibilidade em frangos de corte
(Universidade Federal de Lavras, 2025-08-22) Soares, Márcia das Neves; Bertechini, Antônio Gilberto; Pinheiro, Sarah Gomes; Kaneco, Isabelle Naemi; Fassani, Edison José; Silva, Vanessa Avelar
Multi-protease supplementation was evaluated for its effects on growth performance, carcass yield, intestinal morphology, microbiota, nutrient digestibility, and enzymatic activity in broiler chickens. Three experiments were conducted. In the first, performance, intestinal morphology, and microbiota were assessed in birds fed diets with reduced crude protein and amino acids levels (–4% and –8%) and supplemented with different enzyme doses (100, 200, and 300 g/t), using 2,250 broilers. The second experiment investigated the ileal digestibility of amino acids and the apparent metabolizable energy of corn, soybean meal, and deactivated full-fat soybeans, with or without protease addition (200 g/t), using 480 birds housed in metabolic cages. The third experiment evaluated in vitro the activity of four types of proteases (multi-protease, alkaline, acid, and neutral) at different pH values (3, 6, and 9), as well as the synergism between endo- and exo- proteases. Multi-protease inclusion significantly improved weight gain and feed conversion, positively modulated the intestinal microbiota by increasing the abundance of Firmicutes and Bacteroidetes, and enhanced intestinal morphology, particularly in diets with reduced amino acids. Protein and amino acid digestibility were significantly higher in enzyme-supplemented diets, especially for limiting amino acids such as methionine+cystine, lysine, threonine, and valine. Apparent metabolizable energy (AME and AMEn) was also increased with protease addition, particularly in diets containing deactivated full-fat soybeans. Enzyme activity varied according to protease type, pH, and concentration. Each enzyme performed best within its optimal pH range, with acid protease showing the highest activity at pH 3, neutral protease at pH 9, and alkaline protease exhibiting increasing activity up to pH 9. It is concluded that multi-protease supplementation is an effective strategy to improve productive performance, intestinal health, and nutrient utilization in broiler chickens, especially in diets with reduced crude protein and amino acid content.
Biodiversity and chitinase production of soil fungi in the Cerrado biome of Minas Gerais
(Universidade Federal de Lavras, 2025-09-26) Figueiredo, Cristiane Nascimento; Pylro, Victor Satler; Houbraken, Jos; Batista, Luís Roberto; Crous, Pedro; Carvalho, Teotonio Soares de; Souza, Jorge Teodoro de; Lemos, Leandro Nascimento; Barcante, Joziana Muniz de Paiva
The Brazilian Cerrado is the second largest biome in the country and extends mainly across the central region of Brazil, harboring an exuberant biodiversity of plants and animals. However, this biome has already lost more than 44% of its native vegetation as a result of land-use change for the production of grains, such as soybeans, corn, and coffee, in addition to meat production. The impact of land-use change on the fungal communities of the Cerrado is still poorly understood, as is the diversity of these microorganisms and their enzymatic potential. Thus, the main objectives of this study were to investigate and compare fungal diversity in soils under different land uses, including agricultural areas of regenerative and conventional coffee cultivation, and areas of native Cerrado vegetation, in the municipality of Patrocínio, Minas Gerais. In addition, the study aimed to test the chitinolytic potential and to identify, through polyphasic taxonomy, fungal isolates obtained from the soil of these three different land-use systems. The serial dilution technique was used to isolate a total of 1.481 fungal strains from 60 soil samples. Aliquots of 0.1 mL of the dilutions were transferred to standardized culture media, Dichloran Rose Bengal Chloramphenicol (DRBC) and Dichloran Glycerol 18% (DG18), incubated at 25 °C for 7 days. Through Next-Generation Sequencing (NGS), soil samples from native Cerrado showed significant differences in both alpha and beta diversities; the native Cerrado areas Ce1 and Ce2 presented the lowest alpha diversity among the analyzed areas (Chao1 consistently < 50). However, fungal groups were similar among Cerrado samples, with a higher relative abundance of the phylum Basidiomycota, genera Apiotrichum and Saitozyma. On the other hand, coffee cultivation areas, both conventional and regenerative, presented similar fungal groups belonging to the phylum Ascomycota. Regarding chitinase production, the highest number of fungal strains with activity above 70 U min−1 was isolated from conventional coffee soil, suggesting that the type of management may influence the synthesis of this enzyme. Seven new species of the genus Penicillium were described: P. patrocinensis (section Brevicompacta), P. guarae (section Cinnamopurpurea), P. seriamae (section Guizhouorum), P. beraoi and P. moreirae (section Lanata-Divaricata), P. pequii and P. pluvialis (section Ramosum). Other isolates were identified as occurrence records of 29 species. Of this total, four were identified using partial sequences of the BenA, CaM, and RPB2 genes, while the remaining 25 were identified only through the partial sequence of the BenA gene. These results reinforce that land-use change exerts a strong impact on the fungal communities of the Cerrado. Furthermore, they demonstrate that this biome constitutes an important reservoir of new species, whose diversity presents high potential for biotechnological applications, especially in the production of hydrolytic enzymes such as chitinases.
Enhancing prediction accuracy of portland cement compressive strength at low cost using machine learning and chemometric techniques
(Universidade Federal de Lavras, 2025-08-25) Santos, Stephano Daniel; Ramalho, Teodorico de Castro; Ferreira, Danton Diego; Leal, Daniel Henrique Soares; Araújo, Eric Fernandes de Mello; Mendes, Rafael Farinassi
Portland cement is essential in civil construction, serving as the basis for concrete in modern infrastructures. The 28-day compressive strength is a critical factor in ensuring the durability of structures and is influenced by factors such as composition, proportions, curing process, and environmental conditions. Accurately predicting this strength is essential to optimize produc- tion and ensure concrete quality. Traditional prediction methods, such as MLR and PLS, are limited to complex systems with many variables. In this context, artificial intelligence (AI) techniques, such as artificial neural networks (ANNs), emerge as promising alternatives, capa- ble of modeling non-linear relationships between cement components and their strength. This study developed an ANN model, using a Multilayer Perceptron (MLP), to predict the 28-day compressive strength of Portland cement. The research sought a time- and cost-efficient pre- diction method to capture the complex interactions between cement components and curing conditions. The process included data collection and preprocessing, network architecture selec- tion, hyperparameter selection, model training, and validation. The results showed that the MLP achieved coefficient of determination (R2) of 0.9851, mean square error (MSE) of 0.8744, root- mean-square error (RMSE) of 0.9351, mean absolute error (MAE) of 0.7360 and mean absolute percentage error (MAPE) of 0.7360%, outperforming traditional methods. This demonstrates the potential of ANNs as a robust tool for predicting cement strength, optimizing production processes, and quality control. Validation was performed with independent data, confirming the superiority of the model.
Citogenética e análise genômica em Urochloa humidicola (Rendle) Morrone & Zuloaga
(Universidade Federal de Lavras, 2025-06-30) Damasceno, Ana Gabriela; Techio, Vânia Helena; Mendes, Andrea Beatriz Diverio; Torres, Giovana Augusta; Moraes, Isabella De Campos; Rocha, Laiane Corsini
Urochloa humidicola is among the most widely used forage grasses in Brazil, standing out for its adaptation to poor soils and areas subject to temporary flooding. The U. humidicola germplasm is predominantly composed of apomictic polyploids, with only the H031 accession described as sexual. This genotype presents controversies regarding its origin and genomic composition and was recently characterized as aneuploid (2n = 6x = 36 + 1). This accession has been used as the female parent in crosses with hexaploid apomictic plants of U. humidicola, such as the cultivar BRS Tupi (H016; 2n = 6x = 36).The present study aimed to: (1) comparatively evaluate meiosis and the mode of reproduction of the aneuploid and euploid parental accessions and their respective hybrids, in addition to determining the chromosome number and genome size of the hybrids; and (2) investigate the genomic relationships among the accessions H031, H016, and Dt158 of U. dictyoneura (all belonging to the Humidicola clade), as well as with three diploid species from the Brizantha clade, by applying genomic in situ hybridization (GISH).The hybrids presented 2n = 6x = 36 chromosomes and a smaller genome size. The p779/p780 marker confirmed only the H016 accession as apomictic. Meiotic analysis revealed a lower frequency of irregularities in the euploid accession H016, whereas the hybrids showed high rates of univalents and multivalents, reflecting the genomic differences between the parents. GISH using genomic DNA from diploids of the Brizantha clade and between accessions H031 and H016 enabled the discrimination of differences between the genomes that compose the hexaploid accessions. The U. dictyoneura 4x probe did not allow the discrimination of subgenomes in U. humidicola. The genome of the diploid species from the Brizantha clade (B1B 1 or B2B 2 ) is ancestral to the hexaploids of U. humidicola (H031 and H016). These accessions also present homeologous genomes, here designated A and A′, and have been characterized as autoallopolyploid.