http://bdtd.unoeste.br:8080/jspui/handle/tede/504 Mestrado em Agronomia 2026-10-22T06:35:10Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1803 Título: Qualidade fisiológica de sementes de Megathyrsus ma-ximus produzidas sob diferentes condições edafoclimáticas, de manejo e armazenamento Autor: OLIVEIRA, Gilson da Silva Primeiro orientador: MACHADO NETO, Nelson Barbosa Abstract: The physiological quality of tropical forage crop seeds is important for pasture esta-blishment and productivity. The objective of this study was to evaluate the physiolo-gical quality of Megathyrsus maximus seeds produced in different fields and subjec-ted to various storage conditions, taking into account soil, climate, and management variables. Batches of the M. maximus × M. infestum hybrid and the cultivars ‘Mas-sai,’ ‘MG-12 Paredão,’ ‘Miyagui,’ and ‘Mombaça’ were analyzed. Physical purity was determined upon receipt of the samples. Other evaluations included moisture con-tent, viability by the tetrazolium test, germination, germination rate index, thousand-seed weight, electrical conductivity, hydrogen peroxide content, and crude protein. The samples were evaluated at the initial stage and after six months of storage at room temperature and under refrigeration. The data were analyzed using analysis of variance and multivariate analyses. Variability was observed among the lots, along with distinct responses to storage conditions. In some lots, germination increased after storage, particularly in ‘Massai’ and ‘Mombaça,’ while refrigerated storage was associated with better maintenance of viability in some of the samples. Multivariate analyses revealed associations between physiological attributes, environmental va-riables, and management practices, with patterns that varied across the evaluated fields. Since these analyses identify associations, they do not allow for the attributi-on of an isolated causal effect to these factors. The results indicate that seed quality should be evaluated by considering both the production environment and storage conditions together. Instituição: Universidade do Oeste Paulista Tipo do documento: Tese 2026-09-29T00:00:00Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1802 Título: Correlação entre locais de produção e a qualidade de sementes de urochloa spp. (sin. Brachiaria spp.) em função do manejo e armazenamento Autor: LORENÇONI, Pedro Henrique Lopes Primeiro orientador: CUSTÓDIO, Ceci Castilho Abstract: As tropical forage seeds are not subject to intensive genetic improvement by humans and exhibit long and variable flowering periods depending on the species or cultivar, assessing the longevity of seed lots harvested in different production areas is an essential tool for seed companies. The present study aimed to collect and evaluate information from different production fields of five (5) Brachiaria cultivars: Urochloa brizantha cv. BRS Piatã, Urochloa brizantha cv. Marandu, Urochloa brizantha cv. MG-5 Vitória, Urochloa humidicola cv. Tully, and Urochloa ruziziensis cv. Kennedy. Samples obtained from each production field were physically and physiologically evaluated at three distinct time points and storage conditions: initially; after six months of storage under ambient conditions; and after six months of storage under short-term germplasm storage conditions (10 °C / 30% RH). Following the collection of the results, correlations were established between the parameters observed in the production fields and selected analytical parameters and the performance of the seed lots after the storage period. The results demonstrated that seed physiological quality and seed storage potential are determined by the interaction between weather conditions and crop management. Overall, higher solar radiation and suitable thermal conditions favored seed vigor, whereas high altitude, dry periods, and temperatures outside the optimal range reduced seed quality. Balanced nutrient management, combined with soil correction, was a crucial factor for better results, whereas unbalanced management practices, particularly for nitrogen utilization, impaired physiological quality. Regional differences were evident, with better performance of Urochloa brizantha cultivars produced in Mato Grosso do Sul, Urochloa humidicola in Minas Gerais, and Urochloa ruziziensis in the municipality of Jaborandi, Bahia. The conclusion is that seed quality and longevity depend on integrated management adapted to the environment and genetic material, making it essential to jointly consider field conditions and physiological attributes to optimize the production, storage, and commercialization of seed lots. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação 2026-09-25T00:00:00Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1800 Título: Efeito do níquel na mitigação da fitotoxidez de glufosinato aplicado em pós-emergência da soja IPRO RR2 Autor: Scabeni, Eduardo Verdi Primeiro orientador: Volf, Marcelo Raphael Abstract: New soybean cultivars tolerant to glufosinate ammonium enable more efficient weed management. However, herbicide drift can adversely affect susceptible crops. Nickel (Ni) nutrition has been studied as a potential strategy to mitigate herbicide-induced phytotoxicity, as several studies highlight its role in enhancing tolerance to environmental stresses, including toxicity in annual crops. This study evaluated the effect of foliar Ni application in mitigating phytotoxicity induced by glufosinate ammonium in the susceptible soybean cultivar Intacta RR2 PRO® (IPRO). The experiment was conducted in two locations: Area 1 (LRV) in the municipality of Lucas do Rio Verde and Area 2 (NMT) in the municipality of Nova Mutum. Herbicide applications were performed at the V6 phenological stage (sixth node of the main stem with fully developed leaves), followed by Ni application 120 hours later. Five doses of glufosinate ammonium (0%, 15%, 25%, 50%, and 100% of the maximum recommended dose) and two Ni doses (0% and 100%, equivalent to 60.0 g ha⁻¹) were tested. Phytotoxicity symptoms were assessed through visual observation at 7, 14, and 21 days after application using a standardized phytotoxicity rating scale. At the R8 stage, plant height and yield components were evaluated, including grain yield, thousand-grain weight (TGW), and total pod number (TPN). The results suggest that foliar Ni application partially mitigated the phytotoxic effects of glufosinate ammonium. This mitigating effect was evidenced by its influence on plant height, pod number, and grain yield, as well as by a reduction in visual phytotoxicity symptoms. Therefore, Ni supplementation may represent a promising strategy for alleviating glufosinate ammonium-induced phytotoxicity in soybean cultivation. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação 2026-04-25T00:00:00Z http://bdtd.unoeste.br:8080/jspui/handle/jspui/1755 Título: Identificação e caracterização molecular da família das expansinas no fruto do Coffea arábica L. Autor: Lobo, Luís Gustavo Gomes Primeiro orientador: Santos, Tiago Benedito dos Abstract: The mechanism of fruit development in coffee plants is characterized by intense cell division, elongation and relaxation of the cell wall, processes related to the action of certain proteins, including expansins. Expansins (EXPs) represent a gene family and symbol in four subfamilies: α-expansin (EXPA), β-expansin (EXPB), expansin-like A (EXLA) and expansin-like B (EXLB). The aim of this study was to characterize expansins using bioinformatics tools and the molecular characterization of coffee fruits in the perisperm, endosperm and pericarp phases. The characterization of these genes began with the collection of information contained in the NCBI (National Center for Biotechnology Information) and Phytozome databases. Then, the following tools were used: ExPASsy and GRAVY (for physicochemical information); PlantmPLoc (subcellular localization); TAIR (orthologous genes); Gene structure: GSDS (exon/intro); MapGene2chromosomoe (MG2C- physical mapping of chromosomes); sequence alignment using MEGA 11 (phylogenetic analysis); Phyre2 (3D protein structures); MEME (Multiple Em for Motif Elicitation- conserved domains); PlantCARE (gene regulatory regions); and TBtools information on Ka/Ks (non-coincident and symbolic) and collinearity test. For gene expression, C. arabica L. grains were found at four development stages (30 DAF, 90 DAF, 120 DAF and 180 DAF) and subjected to qRT- PCR (quantitative real-time reverse transcription PCR) analysis. Forty-five expansin genes were characterized in silico and their physicochemical patterns contained a variation of 240-300 amino acids (aa), molecular weight 21.18 to 32.27 kDa, isoelectric point (pI) 4.35 to 9.68, and all were located in the cell wall. However, it was observed that their appearances seemed hydrophobic. The gene structure (exon/introns) varied from 2/1 to 6/5. The phylogenetic relationship classified them according to the four expansin subfamilies, forming five groups. The genes were unevenly distributed in the 11 chromosomes of C. arabica L.. The conserved domains varied from two to five. The DPBB and CBM63 domains were described in their 3D structures of each protein. In the synthesis of the CaEXPA genes, it showed greater similarity with the genomes of Oryza sativa and Arabidopsis thaliana, and the duplication of some genes was positive in the Ka/Ks analysis. The qRT-PCR result showed that the CaEXPA1, CaEXPA2, CaEXPA4, CaEXPA6, CaEXLA10, and CaEXLB11 genes were expressed during the four periods of fruit development. The CaEXPA1 gene showed greater pressure during 30 DAF, 90 DAF, and 120 DAF, while the CaEXPA4 gene was the most expressed among the genes evaluated, having a high expression in all periods of coffee bean development. This information establishes the basis for future research on the functional characteristics and molecular mechanisms of expansion genes in C. arabica L. in different coffee bean development projects. Instituição: Universidade do Oeste Paulista Tipo do documento: Dissertação 2025-04-16T00:00:00Z