Principais Coleções do Repositório
Submissões Recentes
tese
Integrative characterization of physiological and molecular regulation of hop (Humulus lupulus l.) development: photoperiod and hormonal signaling
(Universidade Federal de Lavras, 2026-09-18) Gutiérrez, Robert Yonel Márquez; Oliveira, Raphael Ricon de; https://orcid.org/0000-0002-3971-0021; Chalfun Junior, Antonio; https://orcid.org/0000-0002-1794-9429; Benedito, Vagner Augusto; https://orcid.org/0000-0002-2131-7651; Maia, Lucas Gontijo Silva; https://orcid.org/0000-0001-9545-7035; Zsogon, Agustin; https://orcid.org/0000-0001-7828-7425
Hop cultivation has expanded into tropical and subtropical regions due to its high added value and importance to the industry, particularly the brewing industry. However, large-scale production in these regions remains challenging, mainly because premature flowering limits the vegetative growth required to achieve high yields. Competitive production is estimated to require approximately 3 kg of female inflorescences, known as strobiles or cones, per plant, which develop mainly on reproductive lateral shoots. Under short-day conditions (<16 h of light), these shoots fail to develop, and plants transition prematurely to flowering. Extending the photoperiod to approximately 17 h delays flowering and maintains vegetative growth. However, the need for continuous artificial light supplementation over several months represents an environmental and socioeconomic limitation, particularly in rural regions affected by unreliable electricity supply, while the use of fossil fuels is not a sustainable alternative. The ability of hop plants to maintain vegetative growth under extended photoperiods suggests the existence of endogenous mechanisms capable of integrating environmental signals and regulating the reproductive transition. In this context, this thesis aimed to provide an integrative characterization of the physiological and molecular mechanisms involved in the response of hop to photoperiod extension. In the first study, we demonstrated that exogenous GA₃ application promotes lateral shoot development and delays flowering under short-day conditions. In the second study, we demonstrated that photoperiod extension alters the expression of genes involved in gibberellin biosynthesis and signaling, and that these responses are modulated by nocturnal temperature, revealing an interaction between photoperiodic and thermal signals. In the third study, we characterized a family of transcription factors with expression patterns associated with different tissues and developmental stages, whose members have been implicated in the regulation of plant architecture in other species. Together, these results contribute to understanding how hormonal regulation, gene expression, and plant architecture participate in maintaining vegetative growth and delaying flowering. Therefore, these findings provide a basis for breeding programs aimed at developing cultivars that are less dependent on artificial light supplementation, potentially enabling more efficient and sustainable hop production in tropical and subtropical regions.
tese
Governança e sustentabilidade hídrico-ambiental na UPGRH dos Afluentes do Alto São Francisco: do diagnóstico territorial ao desenvolvimento do ICSA e à proposição do Selo Carranca
(Universidade Federal de Lavras, 2026-09-30) Santos, Flávio Andreote dos; Borges, Luís Antônio Coimbra; https://orcid.org/00000-0003-0344-5008; Acerbi Júnior, Fausto Weimar; https://orcid.org/: 0000-0002-9553-0148; Guimarães, Bergson Cardoso; França, Luciano Cavalcante de Jesus; https://orcid.org/0000-0002-8885-972X
Water governance requires instruments capable of integrating territorial assessment, institutional capacity, environmental conservation, information production, and mechanisms for promoting improvements in public management. This thesis aimed to analyze hydroenvironmental sustainability in the Water Resources Planning and Management Unit of the Tributaries of the Upper São Francisco River (UPGRH SF1) through an investigative trajectory that began with the identification of weaknesses in regional water governance, advanced to the development of a composite index, and culminated in the proposal of a municipal certification system. The study adopted an applied, exploratory, descriptive, documentary, quantitative, and proposal-oriented approach and was organized into complementary studies. Initially, data on water-use permits and registrations of water uses considered insignificant were examined, revealing substantial growth in simplified water-use regularization, inconsistencies in selfreported information, and limitations in auditing and monitoring mechanisms. Subsequently, Payment for Environmental Services (PES) projects were analyzed, with emphasis on the participation of small-scale rural producers, the restoration of degraded areas, and the relevance of social mobilization in the UPGRH SF1. Based on these assessments, the Composite HydroEnvironmental Sustainability Index (ICSA) was developed, comprising 14 subindicators distributed across five dimensions: institutional management and governance; sanitation and pollution control; environmental conservation and restoration; water resources information and monitoring; and environmental education and mobilization. The index was applied to the 29 municipalities within the water resources management unit using official data, normalization on a scale from 0 to 100, statistical procedures, and geospatial analysis. The results revealed marked territorial heterogeneity and indicated that hydro-environmental performance depends on the convergence of infrastructure, planning, institutional capacity, information quality, environmental conservation, and social participation. Based on the ICSA, the Carranca Seal for Hydro-Environmental Sustainability was proposed as a certification system structured around progressive performance levels, technical criteria, information validation, institutional governance, monitoring, and periodic revalidation. It was concluded that integrating territorial assessment, composite indicators, and certification can enhance planning capacity, public policy prioritization, transparency, and the continuous improvement of water governance at the municipal and river-basin scales.
dissertação
Mapeamento do uso terapêutico e segurança da Cannabis sativa em Alzheimer, esclerose múltipla e Parkinson: revisão de escopo
(Universidade Federal de Lavras, 2026-05-29) Leite, Bruno da Silva; Dourado, Stela Márcia Pereira; Pereira, Luciano José; Soares, Mirelle Inácio; Pereira, Luciano José
Neurodegenerative diseases (Alzheimer's Disease, Parkinson's Disease, and Multiple Sclerosis) represent a growing global public health challenge, with conventional therapies showing limited efficacy. Cannabis sativa derivatives, especially cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), have attracted interest due to their pleiotropic properties and modulation of the Endocannabinoid System. The entourage effect suggests therapeutic superiority of full-spectrum formulations over chemical isolates. The objective of this study was to map the available scientific evidence on the therapeutic potential and safety profile of Cannabis sativa derivatives in adults and older adults with Alzheimer's Disease, Multiple Sclerosis, and Parkinson's Disease, identifying gaps in the literature. A scoping review was conducted according to the Joanna Briggs Institute (JBI) guidelines and reported following PRISMA-ScR. The search was performed in eight databases (PubMed, Cochrane Library, Web of Science, Scopus, Science Direct, SciELO, LILACS, and Google Scholar) in June 2026, without language or period restrictions. Primary and secondary studies with data on therapeutic efficacy and safety in humans were included. Data synthesis was conducted using basic qualitative content analysis with an inductive approach. A total of 150 studies were included (77 primary and 73 secondary). Multiple Sclerosis concentrated the largest volume of evidence (62.7%), followed by Parkinson's Disease (19.3%) and Alzheimer's Disease (10.0%). The United Kingdom, Italy, and Brazil were the countries with the highest number of publications. In MS, nabiximols (THC:CBD) significantly reduced subjective spasticity (NRS) in 75.0% of RCTs, with responders ranging from 37% to 77.4%, although without objective changes on the Modified Ashworth Scale. In PD, results were inconsistent for motor symptoms but promising for non-motor symptoms (anxiety, quality of life, dyskinesia). In AD, benefits were concentrated on agitation control, without consistent cognitive effects. Full-spectrum formulations showed superior efficacy (77.1%) compared to isolates (35.0%). The safety profile was favorable, with mild to moderate adverse events (dizziness 14-59%, somnolence 5-42%, fatigue 6-62%). Cannabis derivatives present variable therapeutic potential depending on pathology and formulation, with more robust evidence for spasticity in MS and non-motor symptoms in PD. Gaps include dosage standardization, long-term evidence, objective biomarkers, and studies in older populations. Future research should prioritize clinical trials with active comparators and prolonged follow-up to consolidate clinical guidelines.
dissertação
Síntese multicomponente de derivados de quinolinas e suas aplicações como fungicida
(Universidade Federal de Lavras, 2026-08-28) Vargas, Elías Leonel; Thomasi, Sérgio Scherrer; https://orcid.org/0000-0001-6493-0723; Bellete, Barbara Sayuri; https://orcid.org/0000-0001-7063-9449; Souza, Jorge Teodoro de; https://orcid.org/0000-0002-2970-4525; Oliveira, Lyege Magalhães; https://orcid.org/0000-0001-8995-0317
The increase in agricultural losses caused by phytopathogenic fungi, associated with the intensive use of synthetic fungicides and the emergence of microbial resistance, has encouraged the search for new molecules with antifungal potential. In this context, nitrogen-containing heterocyclic compounds, such as quinolines and hexahydroquinolines, stand out due to their structural versatility and the wide range of biological activities reported in the literature. Therefore, this study aimed to synthesize, characterize, and evaluate the antifungal activity of hexahydroquinoline and quinoline-4-carboxylic acid derivatives against phytopathogenic fungi. The hexahydroquinoline derivatives were obtained through a Hantzsch-type multicomponent reaction using aromatic aldehydes, ethyl acetoacetate, cyclohexane-1,3-dione, and ammonium acetate. The quinoline-4- carboxylic acid derivatives were synthesized through an adaptation of the Doebner reaction, using substituted anilines, aromatic aldehydes, and sodium pyruvate. The obtained compounds were characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry, and 1H and 13C nuclear magnetic resonance, allowing confirmation of the proposed structures. Antifungal activity was evaluated by the poisoned food method in PDA medium against Fusarium graminearum and Alternaria alternata. The hexahydroquinoline derivatives showed low inhibitory efficiency against the evaluated fungi, with the fluorinated derivative showing a relatively better performance against F. graminearum. In contrast, the quinoline-4-carboxylic acid derivatives showed greater potential against A. alternata with EC50 values of approximately 160 and 240 ppm. Overall, the results indicate that the quinoline-4- carboxylic acid core showed greater antifungal potential than the hexahydroquinoline core under the evaluated conditions.
dissertação
Seletividade de herbicidas pré-emergentes a cultivares de feijão-comum
(Universidade Federal de Lavras, 2026-07-10) Manoel, Pedro Lucas de Carvalho; Melo, Christiane Augusta Diniz; https://orcid.org/0000-0001-6385-2153; Moreira, Silvino Guimarães; https://orcid.org/0000-0002-3631-0305; Silva, Amilton Ferreira da; https://orcid.org/0000-0001-7122-2688; Carneiro, Vinícius Quintão; https://orcid.org/0000-0001-9697-1423
Common bean has a limited number of herbicides registered for pre-emergence application. In this context, this study aimed to evaluate the selectivity of different pre-emergence herbicides in four common bean cultivars. Four experiments were conducted per growing season, one for each bean cultivar, at the Center for Development and Technology Transfer (CDTT) of the Federal University of Lavras, in Ijaci, Minas Gerais, Brazil, during the 2024/2025 and 2025/2026 growing seasons. The experimental design was a randomized complete block design (RCBD), with four replications. Eleven herbicides were applied in pre-emergence, either individually or in mixtures, as follows (g a.i. ha⁻¹): flumioxazin + pyroxasulfone (80 + 120); flumioxazin + imazethapyr (100 + 200); S-metolachlor + fomesafen (1294 + 284); flumioxazin + S-metolachlor (31.5 + 630); ethoxysulfuron (24); flumioxazin (50); pyroxasulfone (150); imazethapyr (106); S-metolachlor (960); pendimethalin (910); and linuron (450), in addition to two controls, with and without mechanical weed control. Four common bean (Phaseolus vulgaris L.) genotypes were evaluated: IAC 1849, IAC 1850, IAC 2051, and TAA Marhe. Herbicides were applied immediately after crop sowing. Each plot consisted of five rows, six meters in length, spaced 0.6 m apart, with the three central rows considered the experimental unit. At 7, 14, 21, and 28 days after application (DAA), visual assessments of crop injury and weed control were performed in the useful area of each plot. Before harvest, the final bean plant population, plant height, number of pods per plant (NPP), and number of grains per plant (NGP) were evaluated. After bean harvest, the thousand-grain weight and yield were assessed, with yield corrected to 13% moisture content. Data were subjected to analysis of variance (ANOVA). When a significant effect was detected, herbicide treatment means were grouped using the Scott-Knott test at 5% significance level. In the 2024/2025 growing season, lower levels of crop injury and greater weed control efficiency were observed compared with the 2025/2026 growing season. It was concluded that ethoxysulfuron was selective for the TAA Marhe cultivar and S-metolachlor + fomesafen was selective for the IAC 1849 cultivar when applied in pre-emergence. The herbicides linuron, flumioxazin + S-metolachlor, S-metolachlor, S-metolachlor + fomesafen, flumioxazin, and pendimethalin were selective for the IAC 1850 cultivar, whereas linuron, flumioxazin + S-metolachlor, S-metolachlor + fomesafen, ethoxysulfuron, flumioxazin + pyroxasulfone, pendimethalin, and imazethapyr were selective for the IAC 2051 cultivar.